Scheme Extensions Aa thru ds:c*

 

 

Technical Article
Scheme is a public domain programming language, based on the LISP language, that uses an interpreter to run commands. ACIS provides extensions (written in C++) to the native Scheme language that can be used by an application to interact with ACIS through its Scheme Interpreter. The C++ source files for ACIS Scheme extensions are provided with the product. Spatials Scheme based demonstration application, Scheme ACIS Interface Driver Extension (Scheme AIDE), also uses these Scheme extensions and the Scheme Interpreter.

adv-cover:cover-circuit

Action
Creates a face from the circuit containing the given edge.

Filename
scm/scmext/ds/acovr_scm.cpp

APIs
api_advanced_cover

Syntax
(adv-cover:cover-circuit edge adv-cover-opts)

Arg Types
edge edge
adv-cover-opts AdvCover_Opt

Returns
face
Description
This Scheme extension attempts to create a face by covering the circuit containing the input edge. The AdvCover_Opt object adv-cover-opts (see adv-cover:options)is used to provide additional information to be used in creating the covering surface, such as requirements for continuity (G0 or G1) with adjacent surfaces.
Arguments
edge is the input edge.

adv-cover-opts is the Advanced Covering options.

Limitations
The circuit must be plane projectable. Refer to the Advanced Covering section of the ADM component for further discussion of limitations.
; adv-cover:cover-circuit
; Define the edge
(define e (edge:spline (list
       (position 0 0 0) (position 1 1 .3)
       (position 0 2 0) (position -1 1 .3)
       (position 0 0 0))))
;; e
; Make the wire body.
(define wire (wire-body e))
;; wire
(define e (list-ref (entity:edges wire) 0))
;; e
; Cover the wire.
(define my-ent (adv-cover:cover-circuit e ))
;; my-ent

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adv-cover:cover-edges

Action
Creates a face from the circuit composed of the given edges

Filename
scm/scmext/ds/acovr_scm.cpp

APIs
api_advanced_cover_no_stitch

Syntax
(adv-cover:cover-edges edge-list adv-cover-opts)

Arg Types
edge-list (edge... )
adv-cover-opts AdvCover_Opt

Returns
face
Description
This Scheme extension attempts to create a face by covering the circuit composed of the input edges. The edges may come from arbitrary combinations of wires and solids, but must form a closed circuit, within SPAresabs. The AdvCover_Opt object adv-cover-opts (see adv-cover:options) is used to provide additional information to be used in creating the covering surface, such as requirements for continuity (G0 or G1) with adjacent surfaces.
Arguments
edge-list is list of input edges.

adv-cover-opts is the Advanced Covering options.

Limitations
The list of edges must form a closed circuit, within SPAresabs. The circuit of edges must be plane projectable.
Refer to the Advanced Covering section of the ADM component for further discussion of limitations.
; adv-cover:cover-edges
(part:clear)
;; #t
; Make a spline edge
(define e1 (edge:spline (list (position 4 -3 -1)
       (position 5 0 0)(position 4 3 1)(position 3 4 2)
       (position 0 5 3)(position -3 4 2)(position -4 3 1)
       (position -5 0 0)(position -4 -3 -1)(position -3 -4 -2)
       (position 0 -5 -3)(position 3 -4 -2)(position 4 -3 -1))
       "periodic"))
;; e1
; Split spline edge and make 2 edges
(define elist (edge:split e1 (position 0 5 3)))
;; elist
; Make 2 wire bodies, one from each edge
(define wi1 (wire-body (list (list-ref elist 0))))
;; wi1
(define wi2 (wire-body (list (list-ref elist 1))))
;; wi2
; Get the handles for the edges in the wires
(define e1 (list-ref (entity:edges wi1) 0))
;; e1
(define e2 (list-ref (entity:edges wi2) 0))
;; e2
; Cover the edges
(adv-cover:cover-edges (list e1 e2))
;; #[entity 10 1]

Figure. adv-cover:cover-edges

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adv-cover:max-gap

Action
Reports the calculated covering surface gaps.

Filename
scm/scmext/ds/acovr_scm.cpp

APIs
None

Syntax
(adv-cover:max-gap adv-cover-opts)

Arg Types
adv-cover-opts AdvCover_Opt

Returns
(real ... )
Description
Given an options returned from adv-cover:options, this command will report the largest surface gaps calculated by the covering kernel. These are G0 and G1. G0 is in model units, G1 is in radians. A value of -1 means no information is available.
Arguments
adv-cover-opts is the Advanced Covering options.

Limitations
The gap reported measures how successful the covering kernel was in pulling the points on the covering surface onto corresponding points on the boundary edges. This is an upper bound on the gap that would be reported by point-perping from these edges to the surface.
; adv-cover:max-gap
; Define the edge
(define e (edge:spline (list
       (position 0 0 0) (position 1 1 .3)
       (position 0 2 0) (position -1 1 .3)
       (position 0 0 0))))
;; e
; Make the wire body.
(define wire (wire-body e))
;; wire
(define e2 (list-ref (entity:edges wire) 0))
;; e2
(define op (adv-cover:options "default_continuity" 0))
;; op
; Cover the wire.
(define my-ent (adv-cover:cover-circuit e2 op))
;; my-ent
(adv-cover:max-gap op)
;; (0.0022310700771418 1.0471975511966)

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adv-cover:options

Action
Sets the options in the data structure to be used by sheet:adv-cover.

Filename
scm/scmext/ds/acovr_scm.cpp

APIs
None

Syntax
(adv-cover:options [name-of-option value] [adv-cover-opts])

Arg Types
name-of-option string
value real | entity | integer
adv-cover-opts AdvCover_Opt

Returns
AdvCover_Opt
Description
The adv-cover:options Scheme extension defines elements in the AdvCover_Opt data structure that are later used for the adv-cover:cover-circuit or adv-cover:recover-face operation. See also the extensive Scheme examples in the ACIS Deformable Modeling Component Use Cases documentation.
Arguments
name-of-option is a string placed within quotation marks. Multiple pairs of name-of-option and value can be specified simultaneously, for example, (define opt (adv-cover:options "default_continuity" 1 "flattening" 0.1)).

     name-of-option values include:









Note: These options are explained in more detail with examples in the ACIS Deformable Modeling Component Use Cases documentation.


value is the value associated with name-of-option.

adv-cover-opts is the Advanced Covering options.
; adv-cover:options
; Example 1
; make an adv-cover-opts object
(define opt (adv-cover:options "default_continuity" 1 "flattening" 0.1))
; make a cylinder and pick an endcap to cover G1
(solid:cylinder 0 0 0 0 0 10 3)
(ray:queue -334.032 -146.77 341.948 0.67652 0.297272 -0.673759 1)
(define f (pick-face))
; recover the end cap
(adv-cover:recover-face f opt)
(render:rebuild)
; adv-cover:options
; Example 2
; make an adv-cover-opts object
(define G0_tol 1.e-4)
(define G1_tol 5.e-3)
(define opt (adv-cover:options "default_continuity" 1 "default_tolerance" G0_tol G1_tol))
; make a cylinder and pick an endcap to cover G1
(solid:cylinder 0 0 0 0 0 10 3)
(ray:queue -334.032 -146.77 341.948 0.67652 0.297272 -0.673759 1)
(define f (pick-face))
; recover the end cap
(adv-cover:recover-face f opt)
(render:rebuild)
; adv-cover:options
; Example 3
; make an adv-cover-opts object
(define v (vertex:from-position (position 0 0 15)))
(define opt (adv-cover:options "guides" (list v)))
; make a cylinder and pick an endcap to cover G1
(solid:cylinder 0 0 0 0 0 10 3)
(ray:queue -334.032 -146.77 341.948 0.67652 0.297272 -0.673759 1)
(define f (pick-face))
; recover the end cap
(adv-cover:recover-face f opt)
(render:rebuild)
; adv-cover:options
; Example 4
; make an adv-cover-opts object
(define e (edge:circular (position 0 0 15) 2))
(define wi (wire-body (list e)))
(define opt (adv-cover:options "guides" (entity:edges wi) ))
; make a cylinder and pick an endcap to cover G1
(solid:cylinder 0 0 0 0 0 10 3)
(ray:queue -334.032 -146.77 341.948 0.67652 0.297272 -0.673759 1)
(define f (pick-face))
; recover the end cap
(adv-cover:recover-face f opt)
(render:rebuild)

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adv-cover:recover-face

Action
Replaces a faces geometry with a surface obtained by covering the faces boundary.

Filename
scm/scmext/ds/acovr_scm.cpp

APIs
api_advanced_cover

Syntax
(adv-cover:recover-face face adv-cover-opts)

Arg Types
face face
adv-cover-opts AdvCover_Opt

Returns
face
Description
This Scheme extension attempts to create new geometry for a face by covering the faces boundary. The AdvCover_Opt object adv-cover-opts (see adv-cover:options) is used to provide additional information to be used in creating the covering surface, such as requirements for continuity (G0 or G1) with adjacent surfaces.
Arguments
face is the input face.

adv-cover-opts is the Advanced Covering options.

Limitations
The faces boundary must be plane projectable. Refer to the Advanced Covering section of the ADM component for further discussion of limitations.
;adv-cover:recover-face
; Define a solid block
(define b (solid:block (position 0 0 0)
                      (position 10 10 10))
;; b
; Pick a face
(define f (list-ref (entity:faces b) 0))
;; f
; Re-cover the face.
(define my-ent (adv-cover:recover-face f ))
;; my-ent

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ds:add-area-cstrn

Action
Adds an area constraint to the deformable model of the owner and returns its tag identifier.

Filename
scm/scmext/ds/dsscm.cpp

APIs
api_dm_get_attrib_dm2acis

Syntax
(ds:add-area-cstrn owner target=1 zone_flag=0
               {uv1 | pick1} {uv2 | pick2})

Arg Types
ght: bold;">
Arg Types
owner entity
target integer
zone-flag integer
uv1 par-pos

uv2

par-pos

pick1

pick-event

pick2

pick-event

Returns
integer
Description
Returns the tag identifier of an area constraint added to the target deformable surface of the owner. The area constraint partitions the shape of the deformable model into two zones, one zone that is free to move and one zone that is fixed. The shape of the zone is a square whose opposite corners are specified by the two uv points, uv1 and uv2.
Area constraints can be used as an alternative to hierarchical surface patches for enforcing local deformations. However, for B-splines and NURBs, this approach to local deformations has some limitations. The shape of the boundary between the fixed and the moving zones is limited to being composed of break line fragments. In addition, only relatively large regions within a surface can support local deformations.
For B-splines and NURBs the boundary of the square must be aligned with the breakpoint values. For convenience, any square shape may be input and the system finds the largest possible square whose boundaries are breakpoint lines that fit within the input square shape. For B-splines and NURBs small squares are too rigid to move. The rule for when a square is large enough to deform depends on the number of elements that the square contains. An element is the area in a B-spline or NURB surface found between a pair of neighboring breakpoints. To deform, a square must contain as many elements as are in the width of one basis function for a control point. For a cubic B-spline or NURB, this means that the smallest square which will deform will be a 4x4 element square. For a quartic surface, the smallest square that can deform is a 5x5 element square.
When zone-flag = 0, the area within the square is free to move and the complement area is fixed. When zone-flag = 1, the area within the square is fixed and the complement area is free to move. The free to move zones are unioned together to define the single free to move zone when multiple are constraints are used.
The uv points may be input as par-pos objects or as pick-events. When a pick-event is used, a domain point location is found by intersecting the ray defined by the pick-events location and viewing angle with the current shape of the target deformable model.

1 = active deformable model 2 = root deformable model

Otherwise, the target is the deformable model whose tag identifier equals target.

Arguments

owner is an ACIS face or edge on which the deformable model lives.

target specifies which deformable model to use in a patch hierarchy.

zone-flag indicates the fixed and complement area.

uv1 and uv2 specify the opposite corners of the square.

pick-event1 and pick-event2 add point constraint at the first intersection between a ray and the deformable surface or curve.
; ds:add-area-cstrn
; ds:add-area-cstrn
; Use an area constraint to enable an isolated
;   deformation
; Build a test square spline face.
; (25x25 control points, x and y side length = 36)
(define dsmodel1 (ds:test-face 25 25 36 36 0))
;; dsmodel1
; Render the elemnts, loads, and constraints.
(ds:set-draw-state dsmodel1 2 (+ ds-draw-elems (+ ds-draw-cstrns ds-draw-loads)))
; Add an area constraint and a pressure load.
(define c1 (ds:add-area-cstrn dsmodel1 2 0 (par-pos 0.2 0.2) (par-pos 0.8 0.8)))
(define c2 (ds:add-dist-press dsmodel1 2 100000))
; solve for the new shape.
(ds:solve dsmodel1 2)
; The square shape, constrained along its edges
; rises in the middle where deformations are allowed
; Commit the deformable surface back to the model.
(ds:commit dsmodel1)
; Perform a zoom-all to see everything.
(zoom-all)

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ds:add-attractor

Action
Adds an attractor load to a deformable model and returns the new attractors tag identifier.

Filename
scm/scmext/ds/dsscm.cpp

APIs
api_dm_get_attrib_dm2acis

Syntax
(ds:add-attractor owner target=1 [xyz-position] [power=2]
gain=100)

Arg Types
owner entity
target integer
xyz-position position
power integer
gain real

Returns
unspecified
Description
Adds an attractor to the owners deformable model and returns the new loads tag identifier. owner is the face or edge being deformed.
The target argument specifies which deformable model to use in a patch hierarchy. Valid values for target are:
 1 = active deformable model
 2 = root deformable model
-1 = active deformable model and offspring
-2 = root deformable model and offspring

Otherwise, the target is the deformable model whose tag identifier equals target.

An attractor acts like a concentrated charge either attracting (negative gains) or repulsing (positive gains) the entire deformable model shape with a 1/distance**power law. The distance is measured from the attractors location to each point on the deformable model.

The input argument xyz-position is optional. When given it is used to define the location of the attractor. When omitted the location is taken as an offset from center of the deformable model in the direction of surface normal at that point.

The input argument power is optional. When omitted it is set to 2. The power specifies how local the effect is. Values of 0 and 1 are global and values of 2 and higher are more local.

Arguments
owner is an ACIS face or edge on which the deformable model lives.

target specifies which deformable model to use in a patch hierarchy.

xyz-position is used to define the location of the attractor.

power specifies how local the effect is.

gain is a measure of how strongly the load pulls the deformable model to its target.
; ds:add-attractor
; Use an attractor to deform a faces shape.
; Build a test square spline face
; (6x6 control points, x and y side length = 36)
(define dsmodel1 (ds:test-face 6 6 36 36 0))
;; dsmodel1
(define erase (entity:erase dsmodel1))
;; erase
; Dont render the face.
; Add a attractor and solve for the new shape.
(define c1 (ds:add-attractor dsmodel1 2 100))
;; c1
(ds:solve dsmodel1 1 1)
;; ()
; OUTPUT Original
; The square shape, constrained along its edges
; rises at its center.
; Move the attractors xyz point and see the effect.
(ds:set-pt-xyz dsmodel1 c1 0 (position 25 25 15))
;; 15
(ds:solve dsmodel1 1 1)
;; ()
; The center of the surface moves to the side.
; OUTPUT Result

Figure. ds:add-attractor

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ds:add-circ-cstrn

Action
Adds and returns the tag identifier for a circular constraint curve to a deformable model.

Filename
scm/scmext/ds/dsscm.cpp

APIs
api_dm_get_attrib_dm2acis

Syntax
(ds:add-circ-cstrn owner target=1 behavior uv-center
    uv-a uv-b [element-count=8 integral-degree=10])

Arg Types
owner entity
target integer
behavior string
uv-center par-pos
uv-a par-pos
uv-b par-pos
element-count integer
integral-degree integer

Returns
integer
Description
Adds a circular curve constraint to the target deformable model of the owner and returns its target identifier. The curve constraints force the surface to interpolate exactly the circular constraint during subsequent deformations.
The target argument specifies which deformable model to use in a patch hierarchy. Valid values for target are:
 1 = active deformable model
 2 = root deformable model
-1 = active deformable model and offspring
-2 = root deformable model and offspring

Otherwise, the target is the deformable model whose tag identifier equals target.

The parameter curve shape is specified by a point: uv-center and two vectors: uv-a, and uv-b. The curve is centered on point uv-center and its minimum and maximum radii are set by the vectors uv-a and uv-b. The equation for the parameter space curve is:
 
P-curve(s) = uv-center + cos(s)uv-a + sin(s)uv-b for 0 <= s <= 2*pi

The u and v values in uv-center, uv-a, and uv-b are scaled to range from 0.0 to 1.0.

The parameter space curve is divided into element-count elements for building the constraint equations. More elements increase the cost of computation but reduce the size of the error.

integral-degree specifies the accuracy of numerical integration used within each element. (A polynomial function of degree integral-degree will be integrated exactly.) Increasing the integral-degree increases the computation cost and reduces the error.

behavior specifies whether the position and/or the tangent of the deformable model across the curve is constrained along the length of the curve. The valid string values for behavior are:
- "position" or "p"
- "tangent" or "t"
- "curvature" or "c"
- "pos_tan" or "pt"
- "pos_cur" or "pc"
- "tan_cur" or "tc"
- "pos_tan_cur" or "ptc"

For link constraints, one of three states for four different parameters must be specified. The valid states are:
0 = off
f = fixed
l = linked

The four different parameters to set are:
- curve_1_position
- curve_1_tangent
- curve_2_position
- curve_2_tangent

Therefore, a total of 81 different behavior states are allowed for a link constraint. These states can be specified by the string pos_?_?_tan_?_? where the question marks can be one of off or o, fixed or f, or linked or l. As an example, the string pos_linked_linked_tan_off_off or pll_too sets the behavior to DM_POS_LINKED | DM_POS_2_LINKED | DM_TAN_FREE | DM_TAN_2_FREE.

Arguments
owner ACIS face or edge on which the deformable model lives.

target  specifies which deformable model to use in a patch hierarchy.

behavior  whether the position and/or the tangent of the deformable model across the curve is constrained along the length of the curve.

uv-center is a center point.

uv-a minimum radius.

uv-b maximum radius.

element-count elements for building the constraint equations.

integral-degree specifies the accuracy of numerical integration used within each element.

Limitations
Circular constraints may only be added to deformable surfaces. They are not supported for deformable curves.
; ds:add-circ-cstrn
; Create a test face for this constraint.
; (6x6 control points, x and y side length = 36)
(define dsmodel1 (ds:test-face 6 6 36 36 0))
;; dsmodel1
; Dont display entity / ds test face exists.
(define erase (entity:erase dsmodel1))
;; erase
; Render the loads and constraints.
(ds:set-draw-state dsmodel1 1
    (+ ds-draw-cstrns ds-draw-loads))
;; ()
; Add a circular constraint at the squares center
(ds:add-circ-cstrn dsmodel1 1 "position"
    (par-pos 0.5 0.5) (par-pos 0 0.3)
    (par-pos 0.3 0))
;; 7
; Toggle off the default crv-cstrns
(ds:toggle-cstrn dsmodel1 1)
;; 0
(ds:toggle-cstrn dsmodel1 2)
;; 0
(ds:toggle-cstrn dsmodel1 3)
;; 6
(ds:toggle-cstrn dsmodel1 4)
;; 6
; OUTPUT Original
; Add a pt-cstrn at the center and track it.
(define cc1 (ds:add-pt-cstrn dsmodel1 1
    "position" (par-pos 0.5 0.5)))
;; cc1
(ds:set-pt-xyz dsmodel1 cc1 0
    (position 20 10 0))
;; 8
; Compute a new deformable model position.
(ds:solve dsmodel1 1 1)
; *** Warning
; (dshusk/ds2acis:DS_LOW_DOF_CNT_WARNING)
; DS_warning - low dof count - Consider ds:split-d
;; ()
; dsmodel1 deforms to interpolate the point
; and the curve constraint.
; Commit the deformable surface back to the model.
(ds:commit dsmodel1)
;; ()
; OUTPUT Result

Figure. ds:add-circ-cstrn

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ds:add-circ-load

Action
Adds a circular curve load and returns its tag identifier to a deformable model.

Filename
scm/scmext/ds/dsscm.cpp

APIs
api_dm_get_attrib_dm2acis

Syntax
(ds:add-circ-load owner target=1 uv-center uv-a uv-b
[gain=100 element-count=8 integral-degree=10])

Arg Types
owner entity
target integer
uv-center par-pos
uv-a par-pos
uv-b par-pos
gain real
element-count integer
integral-degree integer

Returns
integer
Description
Adds a circular curve load to the target deformable model of the owner and returns its target identifier.
The target argument specifies which deformable model to use in a patch hierarchy. Valid values for target are:
 1 = active deformable model
 2 = root deformable model
-1 = active deformable model and offspring
-2 = root deformable model and offspring

Otherwise, the target is the deformable model whose tag identifier equals target.

The curve loads force the points of the surfaces parameter space curve to lie near the image space curve during subsequent deformations. Increasing the gain value forces the load points to remain closer to their current locations. Use curve constraints to interpolate those points.

The parameter space curve is specified by a point: uv-center and two vectors: uv-a, and uv-b. The parameter space curve is centered on point uv-center and its minimum and maximum radii are set by the vectors uv-a and uv-b. The equation for the parameter space curve is:
 
P-curve(s) = uv-center + cos(s)uv-a + sin(s)uv-b for 0 <= s <= 2*pi

The u and v values in uv-center, uv-a, and uv-b are scaled to range from 0.0 to 1.0. gain specifies the stiffness operating between the curves current position and its position in subsequent deformations. Large gain values limit the motion of the curve.

The parameter space curve is divided into element-count elements for building the load equations. More elements increase the cost of computation but reduce the size of the error. The default value is 8.

integral-degree specifies the accuracy of numerical integration used within each element. (A polynomial function of degree integral-degree will be integrated exactly.) Increasing the integral-degree increases the computation cost and reduces the error.

Arguments
owner ACIS face or edge on which the deformable model lives.

target specifies which deformable model to use in a patch hierarchy.

uv-center is a center point.

uv-a minimum radius.

uv-b maximum radius.

gain is a measure of how strongly the load pulls the deformable model to its target.

element-count elements for building the load equations.

integral-degree specifies the accuracy of numerical integration used within each element.

Limitations
Circular loads are only for deformable surfaces. They are not supported for deformable curves.
; ds:add-circ-load
; Add and use a circ crv-cstrn to a square test face
; Build a test square spline face.
; (6x6 control points, x and y side length = 36)
(define dsmodel1 (ds:test-face 6 6 36 36 0))
;; dsmodel1
; Dont display entity / ds test face exists.
(define erase (entity:erase dsmodel1))
;; erase
; Render the loads and constraints.
(ds:set-draw-state dsmodel1 1
    (+ ds-draw-cstrns ds-draw-loads))
;; ()
(ds:add-circ-load dsmodel1 1
    (par-pos 0.5 0.5) (par-pos 0 0.3)
    (par-pos 0.3 0) 100)
;; 7
; Toggle off the default crv-cstrns.
(ds:toggle-cstrn dsmodel1 1)
;; 0
(ds:toggle-cstrn dsmodel1 2)
;; 0
(ds:toggle-cstrn dsmodel1 3)
;; 6
(ds:toggle-cstrn dsmodel1 4)
;; 6
; OUTPUT Original
; Add a pt-cstrn at the center and track it.
(define cc1 (ds:add-pt-cstrn dsmodel1 1
    "position" (par-pos 0.5 0.5)))
;; cc1
(ds:set-pt-xyz dsmodel1 cc1 0
    (position 16 16 10))
;; 8
; Compute a new deformable model position.
(ds:solve dsmodel1 1 1)
;; ()
; dsmodel1 deforms to interpolate the point and
; the curve constraint.
; OUTPUT Result

Figure. ds:add-circ-load

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ds:add-cstrn

Action
Adds point and curve constraints to the specified owners deformable model.

Filename
scm/scmext/ds/dsscm.cpp

APIs
api_dm_get_attrib_dm2acis

Syntax
(ds:add-cstrn owner target=1 {shape | tag} behavior
{uv-pts}+ [integral-degree=10])

Arg Types
owner entity
target integer
shape string
tag integer
behavior string
{uv-pts}+ par-pos | pick-event
integral-degree integer

Returns
integer
Description
Adds a constraint to the owner target deformable model and returns the new constraints tag identifier.
The target argument specifies which deformable model to use in a patch hierarchy. Valid values for target are:
 1 = active deformable model
 2 = root deformable model
-1 = active deformable model and offspring
-2 = root deformable model and offspring

Otherwise, the target is the deformable model whose tag identifier equals target.

Subsequent arguments to this extension specify what kind of constraint is being added.

owner is the face or edge being deformed.

shape specifies which loci of points in the deformable model are constrained. The supported constraints include point constraints and curve constraints in the form of straights, parabolas, and ellipses. An ellipse may be used to insert a circle constraint.

Valid values for shape are:
- "point"
- "straight"
- "parabola"
- "circ"

tag is the shape of a constraint taken from an existing load. When tag identifies a spring, a pressure point, or a spring load, one or more point constraints are added to the system and the loads are deleted. When tag identifies a curve load, a curve constraint is added.

behavior specifies whether the position, the tangent, and/or the curvature of the deformable model across the curve is constrained along the length of the curve. The valid string values for behavior are:
for single behaviors:
- "position" or "p"
- "tangent" or "t"
- "tan2" or "t2"
- "normal" or "n"
- "binormal" or "b"
- "curvature" or "c"
- "curv2" or "c2"

for 2 behavior combinations:
- "pos_tan" or "pt"
- "pos_tan2" or "pt2"
- "pos_norm" or "pn"
- "pos_binorm" or "pb"
- "pos_cur" or "pc"
- "pos_cur2" or "pc2"
- "tan_tan2" or "tt2"
- "tan_norm" or "tn"
- "tan_binorm" or "tb"
- "tan2_norm" or "t2n"
- "cur_cur2" or "cc2"

for 3 behavior combinations:
- "pos_tan_tan2" or "ptt2"
- "pos_tan_norm" or "ptn"
- "pos_tan_binorm" or "ptb"
- "pos_tan2_norm" or "pt2n"
- "pos_tan2_cur" or "pt2c"
- "pos_tan_cur2" or "ptc2"
- "pos_cur_cur2" or "pcc2"
- "tan_tan2_norm" or "tt2n"
- "pos_tan_tan2_norm" or "ptt2n"

Therefore, a large number of different behavior states are allowed for a link constraint. These states can be specified by the string pos_?_?_tan_?_? where the question marks can be one of off or o, fixed or f, or linked or l. As an example, the string pos_linked_linked_tan_off_off or pll_too sets the behavior to DM_POS_LINKED | DM_POS_2_LINKED | DM_TAN_FREE | DM_TAN_2_FREE.

uv-pts are one or more par-pos point locations that parameterize a shape. Each par-pos location specifies a point in the domain space of the deformable model. The coordinates of any par-pos point are scaled to the range of 0.0 to 1.0. Any uv-pt may be specified explicitly by a par-pos object or by a pick event. When a uv-pt is specified by a pick event, the required par-pos is calculated as the first intersection between the pick ray contained within the pick event and the shape of the deformable model. Different shapes require different numbers of uv-pts. Do not combine uv-pts into a list.

Shape Count Description
point

1

 The points uv point
straight

2

 Begin uv point and end uv point
parabola

3

 Begin uv point, tangent intersection point, and end uv point
circ

3

 Center uv point, a axis end uv point, and b axis end uv point
tag

0

 Shape is taken from an existing load and the load is deleted

A parabola is defined by three uv points: the two end points and a point at the intersection of the two end tangent vectors.

A circ is a closed elliptical arc defined by a center point (uv_ctr), and two vectors (uv_a and uv_b) which mark the distance between the center point and two points on the ellipse. The shape of the curve in domain space is given by:
C(theta) = uv_ctr + uv_a*cos(theta) + uv_b*sin(theta)
When the a and b vectors have the same lengths the circ is a circle centered on the given center point. A well paramaterized circ is best built when the a and b vectors are orthogonal to one another. For example:
uv_ctr = [.5,.5], uv_a = [.2,0], uv_b = [0,.2]

This makes a well parameterized circle.

integral-degree specifies the accuracy of numerical integration used within each element. (A polynomial function of degree integral-degree will be integrated exactly.) Increasing the integral-degree increases the computation cost and reduces the error.

Arguments
owner is an ACIS face or edge on which the deformable model lives.

target specifies which deformable model to use in a patch hierarchy.

shape is specifies which loci of points in the deformable model are constrained.

tag is the shape of a constraint taken from an existing load.

behavior specifies whether the position, the tangent, and/or the curvature of the deformable model across the curve is constrained along the length of the curve.

{uv-pts} are one or more par_pos point locations that parameterize a shape.

integral-degree specifies the accuracy of numerical integration used within each element.

Limitations
This Scheme extensions will not always work correctly if the target argument is not already the active deformable model. A target deformable model can be made active by calling a query Scheme extensions on it, such as ds:get-tag-summary or ds:get-alpha. This should be used immediately before calling the extension.
; ds:add-cstrn
; Add and use a point constraint to a square test
; face
; Build a test square spline face.
; (6x6 control points, x and y side length = 36)
(define dsmodel1 (ds:test-face 6 6 36 36 0))
;; dsmodel1
; Dont display entity / ds test face exists.
(define erase (entity:erase dsmodel1))
;; erase
; Render the loads and constraints.
(ds:set-draw-state dsmodel1 1
    (+ ds-draw-cstrns ds-draw-loads))
;; ()
; OUTPUT Original
; Add a point constraint at the squares center.
(define cc1 (ds:add-cstrn dsmodel1 1
    "point" "position" (par-pos 0.5 0.5)))
;; cc1
(ds:set-pt-xyz dsmodel1 cc1 0
    (position 16 16 10))
;; 8
; Compute a new deformable model position.
(ds:solve dsmodel1 1 1)
;; ()
; dsmodel1 deforms to interpolate the point and
; the curve constraint.
; OUTPUT Result

Figure. ds:add-cstrn

[Top]

ds:add-dist-press

Action
Adds a distributed pressure to the deformable model and returns its tag.

Filename
scm/scmext/ds/dsscm.cpp

APIs
api_dm_get_attrib_dm2acis

Syntax
(ds:add-dist-press owner target=1 gain=100 [pos-param1 pos-param2])

Arg Types
owner entity
target integer
gain real
pos-param1 par-pos
pos-param2 par-pos

Returns
integer
Description
Adds a distributed pressure to the target deformable model of the owner and returns the tag identifier of newly added distributed pressure.
The target argument specifies which deformable model to use in a patch hierarchy. Valid values for target are:
 1 = active deformable model
 2 = root deformable model
-1 = active deformable model and offspring
-2 = root deformable model and offspring

Otherwise, the target is the deformable model whose tag identifier equals target.

The distributed pressure is a force of amplitude (gain) acting in the normal direction of the surface. The distributed pressure is applied to the entire surface by default.

If the two optional parametric position arguments, pos-param1 and pos-param2, are used, they limit the distributed pressure domain to a box whose corners are specified by pos-param1 and pos-param2 in the parameter space of the deformable surface. The param1 and param2 values in pos-param1 and pos-param2 are scaled to range from 0.0 to 1.0. The distributed pressure is an effective puff command. It causes surfaces to billow in the direction of the applied pressure.

Arguments
owner is an ACIS face or edge on which the deformable model lives.

target specifies which deformable model to use in a patch hierarchy.

gain is a measure of how strongly the load pulls the deformable model to its target.

pos-param1 is positional parameter.

pos-param2 is positional parameter.
; ds:add-dist-press
; Add a distributed pressure to puff a faces shape
; Build a test square spline face.
; (6x6 control points, x and y side length = 36)
(define dsmodel1 (ds:test-face 6 6 36 36 0))
;; dsmodel1
; Dont display entity / ds test face exists.
(define erase (entity:erase dsmodel1))
;; erase
; Render the loads and constraints.
(ds:set-draw-state dsmodel1 1
    (+ ds-draw-cstrns ds-draw-loads))
;; ()
; Add a distributed pressure and solve for new shape.
(define c1 (ds:add-dist-press dsmodel1 1 2000))
;; c1
(ds:solve dsmodel1 1 1)
;; ()
; The square shape, constrained along its edges,
; rises in its center.
; OUTPUT Original
; Increase the pressures amplitude and effect.
(ds:set-load-gain dsmodel1 c1 10000)
;; 3
(ds:solve dsmodel1 1 1)
;; ()
; The center of the surface moves more.
; OUTPUT Result

Figure. ds:add-dist-press

[Top]

ds:add-parab-cstrn

Action
Adds a curve constraint along a parabolic arc within the parameter space of a deformable surface and returns the constraints tag.

Filename
scm/scmext/ds/dsscm.cpp

APIs
api_dm_get_attrib_dm2acis

Syntax
(ds:add-parab-cstrn owner target=1 behavior
start-ppt tang-xsect-ppt stop-ppt
[integral-degree=10])

Arg Types
owner entity
target integer
behavior string
start-ppt par-pos
tang-xsect-ppt par-pos
stop-ppt par-pos
integral-degree integer

Returns
integer
Description
Adds a curve load to the target deformable model of the owner along a parabolic arc within the domain of the deformable surface. This function is for deformable surfaces only.
The target argument specifies which deformable model to use in a patch hierarchy. Valid values for target are:
 1 = active deformable model
 2 = root deformable model
-1 = active deformable model and offspring
-2 = root deformable model and offspring

Otherwise, the target is the deformable model whose tag identifier equals target.

The parabolic arc runs from start-ppt to stop-ppt and the arcs end tangents intersect at the point tang-xsect_ppt. The u and v values in start-ppt, tang-xsect-ppt, and stop-ppt are scaled to range from 0.0 to 1.0.

integral-degree specifies the accuracy of numerical integration used during the construction of the constraint equations.

behavior specifies whether the position and/or the tangent of the deformable model across the curve is constrained along the length of the curve.

For curve constraints, the allowed behaviors include:
- "position" or "p"
- "tangent" or "t"
- "curvature" or "c"

For the combinations:
- "pos_tan" or "pt"
- "pos_cur" or "pc"

Therefore, a number of different behavior states are allowed for a link constraint. These states can be specified by the string pos_?_?_tan_?_? where the question marks can be one of off or o, fixed or f, or linked or l. As an example, the string pos_linked_linked_tan_off_off or pll_too sets the behavior to DM_POS_LINKED | DM_POS_2_LINKED | DM_TAN_FREE | DM_TAN_2_FREE.

Arguments
owner is an ACIS face or edge on which the deformable model lives.

target specifies which deformable model to use in a patch hierarchy.

behavior specifies whether the position, the tangent, and/or the curvature of the deformable model across the curve is constrained along the length of the curve.

start-ppt starting point of parabolic arc.

stop-ppt ending point of parabolic arc.

tang-xsect-ppt points where arcs end tangents intersect.

integral-degree specifies the accuracy of numerical integration used during the construction of the constraint equations.

Limitations
This is used for deformable surfaces only; it has no effect on deformable curves.

This Scheme extension will not always work correctly if the target argument is not already the active deformable model. A target deformable model can be made active by calling a query Scheme extension on it, such as ds:get-tag-summary or ds:get-alpha. This should be used immediately before calling the extension.
; ds:add-parab-cstrn
; Add to a square test face a parabolic crv-load
; and use it.
; Build a test square spline face.
; (6x6 control points, x and y side length = 36)
(define dsmodel1 (ds:test-face 6 6 36 36 0))
;; dsmodel1
; Dont display entity / ds test face exists.
(define erase (entity:erase dsmodel1))
;; erase
; Render the loads and constraints.
(ds:set-draw-state dsmodel1 1
    (+ ds-draw-cstrns ds-draw-loads))
;; ()
; Toggle off the default edge crv-cstrns.
(ds:toggle-cstrn dsmodel1 1)
;; 0
(ds:toggle-cstrn dsmodel1 2)
;; 0
(ds:toggle-cstrn dsmodel1 3)
;; 6
(ds:toggle-cstrn dsmodel1 4)
;; 6
; Add corner constraints.
(ds:add-pt-cstrn dsmodel1 1 "position"
    (par-pos 1 0))
;; 7
(ds:add-pt-cstrn dsmodel1 1 "position"
    (par-pos 1 1))
;; 8
(ds:add-pt-cstrn dsmodel1 1 "position"
    (par-pos 0 1))
;; 9
; OUTPUT Original
; Add a parabolic load across the squares corner.
(ds:add-parab-cstrn dsmodel1 1 "position"
    (par-pos 0 0.4) (par-pos 0 0)
    (par-pos 0.4 0))
;; 10
; Add a pt-cstrn at the center and track it.
(define cc1 (ds:add-pt-cstrn dsmodel1
    1 "position" (par-pos 0.5 0.5)))
;; cc1
(ds:set-pt-xyz dsmodel1 cc1 0
    (position 18 18 20))
;; 8
; Compute a new deformable model position.
(ds:solve dsmodel1 1 1)
;; ()
; The dsmodel1 deforms to interpolate all the point
; constraints while remaining near the load curve.
; OUTPUT Result

Figure. ds:add-parab-cstrn

[Top]

ds:add-parab-load

Action
Adds a curve load along a parabolic arc within the parameter space of the deformable surface and returns a loads tag.

Filename
scm/scmext/ds/dsscm.cpp

APIs
api_dm_get_attrib_dm2acis

Syntax
(ds:add-parab-load owner target=1 start-ppt
tang-xsect-ppt stop-ppt
[gain=100 integral-degree=10])

Arg Types
owner entity
target integer
start-ppt par-pos
tang-xsect-ppt par-pos
stop-ppt par-pos
gain real
integral-degree integer

Returns
integer
Description
Adds a curve load to the target deformable model of the owner along a parabolic arc within the domain of the deformable surface.
The target argument specifies which deformable model to use in a patch hierarchy. Valid values for target are:
 1 = active deformable model
 2 = root deformable model
-1 = active deformable model and offspring
-2 = root deformable model and offspring

Otherwise, the target is the deformable model whose tag identifier equals target.

The parabolic arc runs from start-ppt to stop-ppt and the arcs end tangents intersect at the point tang-xsect-ppt. The u and v values in start-ppt, tang-xsect-ppt, and stop-ppt are scaled to range from 0.0 to 1.0.

gain specifies the stiffness that attracts the loads domain curve towards its image space curve. The loads image space curve is made by projecting the domain curve into image space using the surfaces shape. This starts the curve load out with two curves that have the same shape.

integral-degree specifies the accuracy of numerical integration used during the construction of the constraint equations.

Arguments
owner is an ACIS face or edge on which the deformable model lives.

target specifies which deformable model to use in a patch hierarchy.

start-ppt starting point of parabolic arc.

stop-ppt ending point of parabolic arc.

tang-xsect-ppt points where arcs end tangents intersect.

gain specifies the stiffness that attracts the loads domain curve towards its image space curve.

integral-degree specifies the accuracy of numerical integration used during the construction of the constraint equations.

Limitations
Parabolic load curves may only be added to deformable surfaces. They cannot be added to deformable curves.

This Scheme extensions will not always work correctly if the target argument is not already the active deformable model. A target deformable model can be made active by calling a query Scheme extensions on it, such as ds:get-tag-summary or ds:get-alpha. This should be used immediately before calling the extension.
; ds:add-parab-load
; Add to a square test face a parabolic crv-load
; and use it.
; Build a test square spline face.
; (6x6 control points, x and y side length = 36)
(define dsmodel1 (ds:test-face 6 6 36 36 0))
;; dsmodel1
; Dont display entity / ds test face exists.
(define erase (entity:erase dsmodel1))
;; erase
; Render the loads and constraints.
(ds:set-draw-state dsmodel1 1
    (+ ds-draw-cstrns ds-draw-loads))
;; ()
; Toggle off the default edge crv-cstrns.
(ds:toggle-cstrn dsmodel1 1)
;; 0
(ds:toggle-cstrn dsmodel1 2)
;; 0
(ds:toggle-cstrn dsmodel1 3)
;; 6
(ds:toggle-cstrn dsmodel1 4)
;; 6
; Add corner constraints.
(ds:add-pt-cstrn dsmodel1 1 "position"
    (par-pos 1 0))
;; 7
(ds:add-pt-cstrn dsmodel1 1 "position"
    (par-pos 1 1))
;; 8
(ds:add-pt-cstrn dsmodel1 1 "position"
    (par-pos 0 1))
;; 9
; OUTPUT Original
; Add a parabolic load across the squares corner.
(ds:add-parab-load dsmodel1 1
    (par-pos 0 0.4) (par-pos 0 0)
    (par-pos 0.4 0) 300)
;; 10
; Add a pt-cstrn at the center and track it.
(define cc1 (ds:add-pt-cstrn dsmodel1 1
    "position" (par-pos 0.5 0.5)))
;; cc1
(ds:set-pt-xyz dsmodel1 cc1 0
    (position 18 18 20))
;; 8
; Compute a new deformable model position.
(ds:solve dsmodel1 1 1)
;; ()
; dsmodel1 deforms to interpolate the point
; constraints while remaining near the load curve.
; OUTPUT Result

Figure. ds:add-parab-load

[Top]

ds:add-patch

Action
Adds a patch to a parent deformable model in preparation for local deformations.

Filename
scm/scmext/ds/dsscm.cpp

APIs
api_dm_add_patch, api_dm_get_attrib_dm2acis

Syntax
(ds:add-patch owner target=1 shape point1 point2 point3
refinement)

Arg Types
owner entity
target integer
shape integer
point1 par-pos
point2 par-pos
point3 par-pos
refinement integer

Returns
integer
Description
Adds a patch to a parent target deformable model in preparation for local deformations. This returns a tag identifier of the patch newly added to the deformable model.
The value of shape selects the seam shape of the boundary. The values are:
1 = square seam
2 = elliptical seam
3 = fillet_square seam

When shape equals 1, a square seam, point1 and point2 define the upper and lower corners of the box and the values of point3, while required, are not used. When shape equals 2, an elliptical seam, the patch is an ellipse defined by the function:
 
W(s) = point1 + point2  * cos(s) + point3 * sin(s)

where s ranges from 0 to 2Pi.

The center of the ellipse is point1. One axis of the ellipse is defined by the vector point2, and the second axis of the ellipse is defined by the vector point3. point2 and point3 are stored as par-pos objects instead of pos-vec objects only because the pos-vec object has not yet been exposed to the Scheme interface. All point arguments are par_pos objects. The points point1, (point1+point2), and (point1+point3) may all have values which range over the unit square which is mapped to the domain of the actual target deformable model.

When shape equals 3, a fillet square seam, point1 and point2 define the upper and lower corners of a square seam where each of the squares corners are rounded off with an arc fillet whose radius equals point3.

The refinement argument specifies the density of the patch control points as compared to the parents. A refinement value of 1 specifies that the new patch control point density is the same as that of the target deformable model. A refinement value of 2 specifies that the new patch has twice the density of control points as the parent. The refinement value must be an integer greater than 0.

The target argument specifies which deformable model to use in a patch hierarchy. Valid values for target are:
 1 = active deformable model
 2 = root deformable model
-1 = active deformable model and offspring
-2 = root deformable model and offspring

Otherwise, the target is the deformable model whose tag identifier equals target.

Arguments
owner is an ACIS face or edge on which the deformable model lives.

target specifies which deformable model to use in a patch hierarchy.

shape selects the seam shape of the boundary.

point1 specifies particular point depending on the model.

point2 specifies particular point depending on the model.

point3 specifies particular point depending on the model.

refinement specifies the density of the patch control points as compared to the parents.

Limitations
At present, elliptical patches cannot be added. Face patches must be completely contained within the interior of their parents. That is, the boundary of the child may not touch or overlap the boundary of its parent.
; ds:add-patch
; Create deformable topology/geometry to illustrate
;   command.
(define dsmodel1 (ds:test-face 6 6 36 36 0))
;; dsmodel1
(define cc1 (ds:add-pt-cstrn dsmodel1
    1 "position" (par-pos 0.5 0.5)))
;; cc1
(ds:set-pt-xyz dsmodel1 cc1 0
    (position 18 18 10))
;; 8
(ds:solve dsmodel1 1 1)
;; ()
; Add patch to deformable model.
(define patch1 (ds:add-patch dsmodel1 1 1
    (par-pos 0.3 0.3) (par-pos 0.5 0.5)
    (par-pos 0.7 0.7) 3))
;; patch1

[Top]

ds:add-pt-cstrn

Action
Adds a point constraint to the specified deformable model of the owner.

Filename
scm/scmext/ds/dsscm.cpp

APIs
api_dm_get_attrib_dm2acis

Syntax
(ds:add-pt-cstrn owner target=1 behavior
    {uv-position | pick-event})

Arg Types
owner entity
target integer
behavior string
uv-position par-pos
pick-event pick-event

Returns
integer
Description
Adds a point constraint to the target deformable surface of the owner and returns the new constraints tag identifier.
The target argument specifies which deformable model to use in a patch hierarchy. Valid values for target are:
1 = active deformable model
2 = root deformable model

Otherwise, the target is the deformable model whose tag identifier equals target.

When a parametric position location is supplied for uv-position, the point constraint is added at the given parametric location. The u and v values in uv-position are scaled to range from 0.0 to 1.0.

behavior specifies whether the position, the tangent, and/or the curvature of the deformable model across the curve is constrained along the length of the curve. The valid string values for behavior are:
for single behaviors:
- "position" or "p"
- "tangent" or "t"
- "tan2" or "t2"
- "normal" or "n"
- "binormal" or "b"
- "curvature" or "c"
- "curv2" or "c2"

for 2 behavior combinations:
- "pos_tan" or "pt"
- "pos_tan2" or "pt2"
- "pos_norm" or "pn"
- "pos_binorm" or "pb"
- "pos_cur" or "pc"
- "pos_cur2" or "pc2"
- "tan_tan2" or "tt2"
- "tan_norm" or "tn"
- "tan_binorm" or "tb"
- "tan2_norm" or "t2n"
- "cur_cur2" or "cc2"

for 3 behavior combinations:
- "pos_tan_tan2" or "ptt2"
- "pos_tan_norm" or "ptn"
- "pos_tan_binorm" or "ptb"
- "pos_tan2_norm" or "pt2n"
- "pos_tan2_cur" or "pt2c"
- "pos_tan_cur2" or "ptc2"
- "pos_cur_cur2" or "pcc2"
- "tan_tan2_norm" or "tt2n"
- "pos_tan_tan2_norm" or "ptt2n"

Therefore, a large number of different behavior states are allowed for a link constraint. These states can be specified by the string pos_?_?_tan_?_? where the question marks can be one of off or o, fixed or f, or linked or l. As an example, the string pos_linked_linked_tan_off_off or pll_too sets the behavior to DM_POS_LINKED | DM_POS_2_LINKED | DM_TAN_FREE | DM_TAN_2_FREE.

Trimmed surfaces occupy only a portion of the unit square. An error is generated if the uv-position is not in a valid portion of the deformable model. When the pick-event is supplied, a point constraint is added at the first intersection between a ray and the deformable surface or curve. The ray starts at the pick point and moves in the viewing direction.

Arguments
owner is an ACIS face or edge on which the deformable model lives.

target specifies which deformable model to use in a patch hierarchy.

behavior specifies whether the position, the tangent, and/or the curvature of the deformable model across the curve is constrained along the length of the curve.

uv-position is  a parametric position location.

pick-event  to add  point constraint at the first intersection between a ray and the deformable surface or curve.
; ds:add-pt-cstrn
; Add and use a point constraint to a square test
; Build a test square spline face.
; (6x6 control points, x and y side length = 36)
(define dsmodel1 (ds:test-face 6 6 36 36 0))
;; dsmodel1
; Dont display entity / ds test face exists
(define erase (entity:erase dsmodel1))
;; erase
; Render the loads and constraints.
(ds:set-draw-state dsmodel1 1
    (+ ds-draw-cstrns ds-draw-loads))
;; ()
; OUTPUT Original
; Add a pt-cstrn at the center and track it
(define cc1 (ds:add-pt-cstrn dsmodel1
    1 "position" (par-pos 0.5 0.5)))
;; cc1
(ds:set-pt-xyz dsmodel1 cc1 0 (position 16 16 10))
;; 8
; Compute a new deformable model position
(ds:solve dsmodel1 1 1)
;; ()
; OUTPUT Result

Figure. ds:add-pt-cstrn

[Top]

ds:add-pt-press

Action
Adds a point pressure load to the deformable model of the owner and returns its tag.

Filename
scm/scmext/ds/dsscm.cpp

APIs
api_dm_get_attrib_dm2acis

Syntax
(ds:add-pt-press owner target=1 {uv-position | pick} gain=100)

Arg Types
owner entity
target integer
uv-position par-pos
pick pick-event
gain real

Returns
integer
Description
Returns the tag identifier of a point pressure added to the target deformable surface of the owner.
The target argument specifies which deformable model to use in a patch hierarchy. Valid values for target are:
 1 = active deformable model
 2 = root deformable model
-1 = active deformable model and offspring
-2 = root deformable model and offspring

Otherwise, the target is the deformable model whose tag identifier equals target.

The point pressure is a single force vector acting in the direction of the surfaces normal with an amplitude set by the input gain. The uv location of the force on the surface is specified explicitly by uv-position or by defining a pick-event. The u and v values in uv-position are scaled to range from 0.0 to 1.0. When a pick-event is input, a line passing through the pick point in the viewing direction is intersected with the surface to find the point at which the pressure is applied.

Arguments
owner ACIS face or edge on which the deformable model lives.

target specifies which deformable model to use in a patch hierarchy.

uv-position is the u and v position values.

pick is a pick event.

gain is a measure of how strongly the load pulls the deformable model to its target.
; ds:add-pt-press
; Use a point pressure load to puff a faces shape
; Build a test square spline face.
; (6x6 control points, x and y side length = 36)
(define dsmodel1 (ds:test-face 6 6 36 36 0))
;; dsmodel1
; Dont display entity / ds test face exists
(define erase (entity:erase dsmodel1))
;; erase
; Render the loads and constraints.
(ds:set-draw-state dsmodel1 1
    (+ ds-draw-cstrns ds-draw-loads))
;; ()
(define c1 (ds:add-spring dsmodel1 1
    (par-pos 0.5 0.5) (position 10 10 15) 200))
;; c1
; Add a point pressure load and
; solve for the new shape
(ds:add-pt-press dsmodel1 1
    (par-pos 0.4 0.8) 10000))
;; 7
(ds:solve dsmodel1 1 1)
;; ()
; OUTPUT Original
; The square shape, constrained along its edges
; rises towards one corner
; Increase the gain for a larger motion
(ds:set-load-gain dsmodel1 c1 20000)
;; 4
(ds:solve dsmodel1 1 1)
;; ()
; Motion is exaggerated.
; Commit the deformable surface back to the model.
(ds:commit dsmodel1)
;; ()
; Perform a zoom-all to see everything. This
; is part of acis.scm.
(zoom-all)
;; #[view 10768947]
; OUTPUT Result

Figure. ds:add-pt-press

[Top]

ds:add-spring

Action
Adds a spring load to the deformable model of an owner and returns its tag.

Filename
scm/scmext/ds/dsscm.cpp

APIs
api_dm_get_attrib_dm2acis

Syntax
(ds:add-spring owner target=1 {uv-position | pick} [xyz-position]
gain=100 [slide-state=0])

Arg Types
owner entity
target integer
uv-position par-pos
pick pick-event
xyz-position position
gain real
slide-state integer

Returns
integer
Description
Returns the tag identifier of a spring load added to the target deformable surface of an owner input face.
The target argument specifies which deformable model to use in a patch hierarchy. Valid values for target are:
 1 = active deformable model
 2 = root deformable model
-1 = active deformable model and offspring
-2 = root deformable model and offspring

Otherwise, the target is the deformable model whose tag identifier equals target.

A spring load is a force that acts on a point in the surface in the direction of a point in three dimensional space with
Amplitude = gain * (distance between the two points)**2

This force acts to keep the point in the surface near its associated three dimensional space point. Increasing the gain value keeps the two points closer together. Use the point constraint feature to force a point on the surface to interpolate a point in three dimensional space. The location of the point in the surface can be given explicitly by the uv-position par-pos or computed from a pick-event. Deformable curves only use the u component of the input par-pos object. The u and v values in uv-position are scaled to range from 0.0 to 1.0.

When a pick-event is used, a line passing through the pick point in the viewing direction is intersected with the surface to compute the surface location for the spring. The three dimensional space point may be given explicitly by including the input position xyz-position. When xyz-position is omitted, the springs uv-position point is projected into three dimensional space through the surfaces shape to find the springs (x,y,z) position.

Springs may slide within the deformable surface so that they tend to act in a direction normal to the surface. If slide-state is 0 (default), the spring is fixed in the surface; if slide-state is 1, the spring is allowed to slide in the surface.

Use point constraints to force a point on the surface to interpolate a point in three dimensional space.

Arguments
owner is an ACIS face or edge on which the deformable model lives.

target specifies which deformable model to use in a patch hierarchy.

uv-position is the location of the point in the surface where force is applied.

pick is a pick event.

gain is a measure of how strongly the load pulls the deformable model to its target.

xyz-position input position in the three dimensional space for the springs position.

slide-state is an integer value which specifies whether the spring is fixed or sliding.
; ds:add-spring
; Use a spring load to puff a faces shape
; Build a test square spline face.
; (6x6 control points, x and y side length = 36)
(define dsmodel1 (ds:test-face 6 6 36 36 0))
;; dsmodel1
; remove entity / ds test face exists
(define erase (entity:erase dsmodel1))
;; erase
; Add a spring and solve for the new shape
(define c1 (ds:add-spring dsmodel1 1
    (par-pos 0.5 0.5) (position 18 18 15) 100))
;; c1
(ds:solve dsmodel1 1 1)
;; ()
; OUTPUT Original
; The square shape, constrained along its edges rises
; at its center
; Move the springs xyz pt and see the affect
(ds:set-pt-xyz dsmodel1 c1 0
    (position 25 25 15))
;; 4
(ds:solve dsmodel1 1 1)
;; ()
; The center of the surface moves to the side
; OUTPUT Result

Figure. ds:add-spring

[Top]

ds:add-spring-curve

Action
Adds a curve load between a straight parameter curve and a line, or between a parameter curve line and an ellipse.

Filename
scm/scmext/ds/dsscm.cpp

APIs
api_dm_get_attrib_dm2acis

Syntax
(ds:add-spring-curve owner target=1 pos-param1 pos-param2
{{position1 position2} | {positionc positiona positionb}}
[gain=100 integral-degree=10])

Arg Types
owner entity
target integer
pos-param1 par-pos
pos-param2 par-pos
position1 position
position2 position
positionc position
positiona position
positionb position
gain real
integral-degree integer

Returns
integer
Description
Builds and returns the tag identifier of a curve load acting between a parameter curve line in the surface of the target and a three dimensional line, or between a parameter curve line in the surface of the target and an ellipse.
The target argument specifies which deformable model to use in a patch hierarchy. Valid values for target are:
 1 = active deformable model
 2 = root deformable model
-1 = active deformable model and offspring
-2 = root deformable model and offspring

Otherwise, the target is the deformable model whose tag identifier equals target.

The load causes the line in the surface to lie near the shape of the three dimensional curve during subsequent deformations. This load is helpful in forcing the shape of the overall surface.

owner identifies the owning entity of the deformable model to be modified. The par-pos, pos-param1 and pos-param2 mark the end points of a straight pcurve in the deformable surface. The u and v values in pos-param1 and pos-param2 are scaled to range from 0.0 to 1.0. The three dimensional space curve type is specified by the number of positions entered. Entering two positions, position1 and position2, causes the command to build a three dimensional space line from point position1 to position2. Entering three positions causes the system to build a closed elliptical three dimensional space curve centered on positionc with minimum and maximum radii specified by the vectors positiona and positionb. The equation of the ellipse is:

Ellipse(s) = pc + cos(s) pa + sin(s) pb
                                                                     where s is 0 <= s <= 1.

gain specifies the stiffness of the spring acting between the pcurve and the three dimensional space curve. Large gain values cause the points along the pcurve to lie closer to the points on the three dimensional space curve during subsequent deformations.

integral-degree specifies the accuracy of numerical integration used within each element. (A polynomial function of degree integral-degree will be integrated exactly.) Increasing the integral-degree increases the computation cost and reduces the error.

Arguments
owner is an ACIS face or edge on which the deformable model lives.

target specifies which deformable model to use in a patch hierarchy.

pos-param1 start point of a straight pcurve in the deformable surface.

pos-param2 end points of a straight pcurve in the deformable surface.

position1 specifies a position to build a three dimensional space line from point position1 to position2.

position2 specifies a position to build a three dimensional space line from point position1 to position2.

positionc specifies a position to build a closed elliptical three dimensional space curve centered on positionc with minimum and maximum radii specified by the vectors positiona and positionb.

positionb specifies a position to build a closed elliptical three dimensional space curve centered on positionc with minimum and maximum radii specified by the vectors positiona and positionb.

positiona specifies a position to build a closed elliptical three dimensional space curve centered on positionc with minimum and maximum radii specified by the vectors positiona and positionb.

gain specifies the stiffness of the spring acting between the pcurve and the three dimensional space curve.

integral-degree specifies the accuracy of numerical integration used within each element.

Limitations
This Scheme extensions will not always work correctly if the target argument is not already the active deformable model. A target deformable model can be made active by calling a query Scheme extensions on it, such as ds:get-tag-summary or ds:get-alpha. This should be used immediately before calling the extension.
; ds:add-spring-curve
; Build a test square spline face.
; (6x6 control points, x and y side length = 36)
(define dsmodel1 (ds:test-face 6 6 36 36 0))
;; dsmodel1
; Dont display entity / ds test face exists
(define erase (entity:erase dsmodel1))
;; erase
; Render the loads and constraints.
(ds:set-draw-state dsmodel1 1
    (+ ds-draw-cstrns ds-draw-loads))
;; ()
; Add a spring and solve for the new shape
(define c1 (ds:add-spring-curve dsmodel1 1
    (par-pos 0 0.5) (par-pos 0.5 0)
    (position 0 18 10) (position 18 0 20) 10000))
;; c1
; OUTPUT Original
; Toggle off the default crv-cstrns
(ds:toggle-cstrn dsmodel1 1)
;; 0
(ds:toggle-cstrn dsmodel1 2)
;; 0
(ds:toggle-cstrn dsmodel1 3)
;; 6
(ds:toggle-cstrn dsmodel1 4)
;; 6
; Add some corner point constraints.
(ds:add-pt-cstrn dsmodel1 1 "position"
    (par-pos 0 0))
;; 8
(ds:add-pt-cstrn dsmodel1 1 "position"
    (par-pos 0 1))
;; 9
(ds:add-pt-cstrn dsmodel1 1 "position"
    (par-pos 1 1))
;; 10
(ds:add-pt-cstrn dsmodel1 1 "position"
    (par-pos 1 0))
;; 11
; Compute a new deformable model position.
(ds:solve dsmodel1 1 1)
;; ()
; The dsmodel1 deforms to interpolate the corner
; points and to lie near the crv-load.
; OUTPUT Result

Figure. ds:add-spring-curve

[Top]

ds:add-spring-set

Action
Adds a spring set to the deformable model and returns its tag.

Filename
scm/scmext/ds/dsscm.cpp

APIs
api_dm_get_attrib_dm2acis

Syntax
(ds:add-spring-set owner target=1 [domain-points] position gain)

Arg Types
owner entity
target integer
domain-points real | (real ...)
position position | (position ...)
gain real

Returns
integer
Description
Returns the tag identifier of a spring set added to the target deformable surface from the owner entity.

The target argument specifies which deformable model to use in a patch hierarchy. Valid values for target are:
 1 = active deformable model
 2 = root deformable model
-1 = active deformable model and offspring
-2 = root deformable model and offspring

Otherwise, the target is the deformable model whose tag identifier equals target.

The domain-points array is interpreted as follows:
case 1d: [u0, u1, ... un]
case 2d: [u0, v0, u1, v1, ... un, vn]

This Scheme extension is only provided to demonstrate the idea of how spring sets can shape deformable surfaces. They are for creating surface descriptions from scattered point sets. The success of the operation depends on a good mapping of image space points to domain locations on the surface. This extension hard codes a very simple mapping. x and y values are mapped directly to u and v values. To try this capability, create point sets that span an xy square and vary in z.
Arguments
owner is an ACIS face or edge on which the deformable model lives.

target specifies which deformable model to use in a patch hierarchy.

domain-points specifies the array of points.

position specifies the surface position.

gain is a measure of how strongly the load pulls the deformable model to its target.
; ds:add-spring-set
; Example command for demonstrating how a deformable
; model can be used to generate a surface shape
; from a set of scattered points.
; Build a test square spline face.
; (12x12 control points, x and y side length = 36)
(define dsmodel1 (ds:test-face 12 12 36 36 0))
;; dsmodel1
; Dont display entity / ds test face exists
(define erase (entity:erase dsmodel1))
;; erase
; Render the loads and constraints.
(ds:set-draw-state dsmodel1 1
    (+ ds-draw-cstrns ds-draw-loads))
;; ()
(ds:set-default-shape dsmodel1 1 0)
;; ()
; toggle the edge constraints
(ds:toggle-cstrn dsmodel1 1)
;; 0
(ds:toggle-cstrn dsmodel1 2)
;; 0
(ds:toggle-cstrn dsmodel1 3)
;; 6
(ds:toggle-cstrn dsmodel1 4)
;; 6
; Sample a simple surface function at a set of
; random points and connect each point to
; the deformable surface with a spring.
(define spr1 (ds:add-spring-set dsmodel1 1
    (ds:test-scatter 65 36 36 25) 5000))
;; spr1
; OUTPUT Original
; Force the surface to deform to the points.
(ds:solve dsmodel1 1 1)
;; ()
; Increase the spring gain and solve again.
(ds:set-load-gain dsmodel1 spr1 30000)
;; 5
(ds:solve dsmodel1 1 1)
;; ()
; Refine the rendering to improve the look
(ds:set-draw-grid dsmodel1 1 30 30)
;; ()
; OUTPUT Result

Figure. ds:add-spring-set

[Top]

ds:add-str-cstrn

Action
Adds a curve constraint that is a straight line in the parametric space of the deformable model and returns its tag.

Filename
scm/scmext/ds/dsscm.cpp

APIs
api_dm_get_attrib_dm2acis

Syntax
(ds:add-str-cstrn owner target=1 behavior
start-point stop-point [integral-degree=10])

Arg Types
owner entity
target integer
behavior string
start-point par-pos
stop-point par-pos
integral-degree integer

Returns
integer
Description
Adds a curve constraint to the target deformable model of the owner along a straight line segment within the domain of the deformable surface. The line runs from start-point to stop-point.
The target argument specifies which deformable model to use in a patch hierarchy. Valid values for target are:
 1 = active deformable model
 2 = root deformable model
-1 = active deformable model and offspring
-2 = root deformable model and offspring

Otherwise, the target is the deformable model whose tag identifier equals target.

For deformable curves only the u values of the input par-pos objects are used. The u and v values in start-point and stop-point are scaled to range from 0.0 to 1.0.

integral-degree specifies the accuracy of numerical integration used within each element. (A polynomial function of degree integral-degree will be integrated exactly.) Increasing the integral-degree increases the computation cost and reduces the error.

behavior specifies whether the position and/or the tangent of the deformable model across the curve is constrained along the length of the curve. The valid string values for behavior are:
For curve constraints allowed behaviors include:
- "pos_tan" or "pt"
- "pos_cur" or "pc" (turns on tangent)
Arguments
owner ACIS face or edge on which the deformable model lives.

target specifies which deformable model to use in a patch hierarchy.

start-point is the starting point of a line.

stop-point is the ending point of a line.

behavior specifies whether the position, the tangent, and/or the curvature of the deformable model across the curve is constrained along the length of the curve.

integral-degree specifies the accuracy of numerical integration used within each element.

Limitations
This Scheme extensions will not always work correctly if the target argument is not already the active deformable model. A target deformable model can be made active by calling a query Scheme extensions on it, such as ds:get-tag-summary or ds:get-alpha. This should be used immediately before calling the extension.
; ds:add-str-cstrn
; Add to a square test face a straight crv-cstrn
; and use it.
; Build a test square spline face.
; (6x6 control points, x and y side length = 36)
(define dsmodel1 (ds:test-face 6 6 36 36 0))
;; dsmodel1
; Dont display entity / ds test face exists
(define erase (entity:erase dsmodel1))
;; erase
; Render the loads and constraints.
(ds:set-draw-state dsmodel1 1
    (+ ds-draw-cstrns ds-draw-loads))
;; ()
; toggle off the default edge crv-cstrns
(ds:toggle-cstrn dsmodel1 1)
;; 0
(ds:toggle-cstrn dsmodel1 2)
;; 0
(ds:toggle-cstrn dsmodel1 3)
;; 6
(ds:toggle-cstrn dsmodel1 4)
;; 6
; Add in corner constraints
(ds:add-pt-cstrn dsmodel1 1 "position"
    (par-pos 1 0))
;; 7
(ds:add-pt-cstrn dsmodel1 1 "position"
    (par-pos 1 1))
;; 8
(ds:add-pt-cstrn dsmodel1 1 "position"
    (par-pos 0 1))
;; 9
; Add straight constraint across squares corner
(ds:add-str-cstrn dsmodel1 1 "position"
    (par-pos 0 0.4) (par-pos 0.4 0))
;; 10
; Add a pt-cstrn at the center and track it
(define cc1 (ds:add-pt-cstrn dsmodel1
    1 "position" (par-pos 0.5 0.5)))
;; cc1
(ds:set-pt-xyz dsmodel1 cc1 0
    (position 18 18 20))
;; 8
; OUTPUT Original
; Compute a new deformable model position
(ds:solve dsmodel1 1 1)
;; ()
; The dsmodel1 deforms to interpolate
; all the point and the curve constraints
; OUTPUT Result

Figure. ds:add-str-cstrn

[Top]

ds:add-str-load

Action
Adds a curve load to a deformable model along a straight parametric line and returns the loads tag.

Filename
scm/scmext/ds/dsscm.cpp

APIs
api_dm_get_attrib_dm2acis

Syntax
(ds:add-str-load owner target=1 start-point stop-point
[gain=100 integral-degree=10])

Arg Types
owner entity
target integer
start-point par-pos
stop-point par-pos
gain real
integral-degree integer

Returns
integer
Description
Adds a curve load to target deformable model of the owner along a straight line segment within the domain of the deformable surface.
The target argument specifies which deformable model to use in a patch hierarchy. Valid values for target are:
 1 = active deformable model
 2 = root deformable model
-1 = active deformable model and offspring
-2 = root deformable model and offspring


Otherwise, the target is the deformable model whose tag identifier equals target.

The line runs from start-point to stop-point. The u and v values in start-point and stop-point are scaled to range from 0.0 to 1.0. The loads image space curve is made by projecting the domain curve into image space using the surfaces shape. This starts the curve load out with two curves that have the same shape.

integral-degree specifies the accuracy of numerical integration used within each element. (A polynomial function of degree integral-degree will be integrated exactly.) Increasing the integral-degree increases the computation cost and reduces the error

Arguments
owner is an ACIS face or edge on which the deformable model lives.

target specifies which deformable model to use in a patch hierarchy.

start-point is the starting point of a line.

stop-point is the ending point of a line.

gain is a measure of how strongly the load pulls the deformable model to its target.

integral-degree specifies the accuracy of numerical integration used within each element.

Limitations
This Scheme extensions will not always work correctly if the target argument is not already the active deformable model. A target deformable model can be made active by calling a query Scheme extensions on it, such as ds:get-tag-summary or ds:get-alpha. This should be used immediately before calling the extension.
; ds:add-str-load
; Add to a square test face a straight crv-load
; and use it.
; Build a test square spline face.
; (6x6 control points, x and y side length = 36)
(define dsmodel1 (ds:test-face 6 6 36 36 0))
;; dsmodel1
; Dont display entity / ds test face exists
(define erase (entity:erase dsmodel1))
;; erase
; Render the loads and constraints.
(ds:set-draw-state dsmodel1 1
    (+ ds-draw-cstrns ds-draw-loads))
;; ()
; toggle off the default edge crv-cstrns
(ds:toggle-cstrn dsmodel1 1)
;; 0
(ds:toggle-cstrn dsmodel1 2)
;; 0
(ds:toggle-cstrn dsmodel1 3)
;; 6
(ds:toggle-cstrn dsmodel1 4)
;; 6
; Add in corner constraints
(ds:add-pt-cstrn dsmodel1 1 "position"
    (par-pos 1 0))
;; 7
(ds:add-pt-cstrn dsmodel1 1 "position"
    (par-pos 1 1))
;; 8
(ds:add-pt-cstrn dsmodel1 1 "position"
    (par-pos 0 1))
;; 9
; OUTPUT Original
; Add a parabolic constraint across the
; squares corner
(ds:add-str-load dsmodel1 1 (par-pos 0 0.4)
    (par-pos 0.4 0) 200)
;; 10
; Add a pt-cstrn at the center and track it
(define cc1 (ds:add-pt-cstrn dsmodel1 1
    "position" (par-pos 0.5 0.5)))
;; cc1
(ds:set-pt-xyz dsmodel1 cc1 0
    (position 18 18 20))
;; 8
; Compute a new deformable model position
(ds:solve dsmodel1 1 1)
;; ()
; dsmodel1 deforms to interpolate
; all the point constraints while staying near the
; curve load
; OUTPUT Result

Figure. ds:add-str-load

[Top]

ds:add-vector-load

Action
Adds a vector load argument to a deformable model and returns the new vector loads tag identifier.

Filename
scm/scmext/ds/dsscm.cpp

APIs
api_dm_get_attrib_dm2acis

Syntax
(ds:add-vector-load owner target=1 [image-vector]
gain=100)

Arg Types
owner entity
target integer
image-vector gvector
gain real

Returns
unspecified
Description
The target argument specifies which deformable model to use in a patch hierarchy. Valid values for target are:
 1 = active deformable model
 2 = root deformable model
-1 = active deformable model and offspring
-2 = root deformable model and offspring

Otherwise, the target is the deformable model whose tag identifier equals target.

A vector load is a constant vector force applied to the entire deformable shape. This load can be used to simulate a gravity-like effect. The input argument image-vector is optional. When given, it is used to define the direction of the vector load. When omitted, the direction is taken as the surface normal for the center of the deformable model.

Arguments
owner is an ACIS face or edge on which the deformable model lives.

target specifies which deformable model to use in a patch hierarchy.

gain is a measure of how strongly the load pulls the deformable model to its target.

image-vector defines the direction of the vector load.
; ds:add-vector-load
; Use a vector_load to puff a faces shape
; define some helpful globals
; Build a test square spline face
; (6x6 control points, x and y side length = 36)
(define dsmodel1 (ds:test-face 6 6 36 36 0))
;; dsmodel1
(define erase (entity:erase dsmodel1))
;; erase
; Dont render the face
; Add a vector_load and solve for the new shape
(define c1 (ds:add-vector-load dsmodel1 2 100))
;; c1
(ds:solve dsmodel1 1 1)
;; ()
; OUTPUT Original
; The square shape, constrained along its edges
; rises at its center
; Move the vector_loads xyz pt and see the affect
(ds:set-pt-xyz dsmodel1 c1 0 (position 25 25 15))
;; 14
(ds:solve dsmodel1 1 1)
;; ()
; The center of the surface moves to the side
; OUTPUT Result

Figure. ds:add-vector-load

[Top]

ds:adm-options

Action
This extension returns an adm-options object for use in ds:start-adm.

Filename
scm/scmext/ds/dsscm.cpp

APIs
None

Syntax
(ds:adm-options name-of-option

 

 {value(s)} {options})

Arg Types
name-of-option string
value integer
options adm-options

Returns
adm-options

Description
This extension returns an adm-options object for use in ds:start-adm and ds:add-link. This allows the use of legacy algorithms in subsequent adm operations.

Errors
use_boundary_loads option requires integer argument.

trim_faces option requires integer argument.

Incorrect adm option.
Arguments
name-of-option is a string containing the name of the option.

value is an integer value containing the value of option.

options is the different adm-options.
; ds:adm-options
; Create a block
(define b1 (solid:block
    (position 5 10 15) (position 10 20 30)))
;; b1
; define adm options
(define ao1 (ds:adm-options "trim_faces" 0))
;; ao1
(define ao2
    (ds:adm-options "use_boundary_loads" 0))
;; ao2
; pick a face
(ray:queue 8.00781 14.6484 500 0 0 -1 1)
;; #[ray (8.00781 14.6484 500) (0 0 -1)]
(define ds-model (pick-face))
;; ds-model
; start adm
(ds:start-adm ds-model)
;; #t

[Top]

ds:commit

Action
Copies a deformable model shape and data back to its ACIS owner.

Filename
scm/scmext/ds/dsscm.cpp

APIs
api_dm_commit_attrib_dm2acis, api_dm_get_attrib_dm2acis

Syntax
(ds:commit owner)

Arg Types
owner entity

Returns
unspecified
Description
Replaces the owner shape data with the shape of the deformable model. Also saves all the deformable model data used to create this shape as an ATTRIB_DSMODEL attribute associated with the owner. When the owner already has an ATTRIB_DSMODEL, it overwrites its data with the current deformable model data. The information in ATTRIB_DSMODEL allows the sculpting to be resumed at the same state in the future.
Arguments
owner ACIS face or edge on which the deformable model lives.
; ds:commit
; Copy a deformable surface model shape and
; deformable model data back to its ACIS face.
; Build a test square spline face.
; (6x6 control points, x and y side length = 36)
(define dsmodel1 (ds:test-face 6 6 36 36 0))
;; dsmodel1
(ds:commit dsmodel1)
;; ()
; No external graphical differences are seen on the
; screen but the internal data structures are now
; different.
; Another Example
; Do not display entity / ds test face exists
(define erase (entity:erase dsmodel1))
;; erase
; Render the loads and constraints.
(ds:set-draw-state dsmodel1 1
    (+ ds-draw-cstrns ds-draw-loads) )
;; ()
; Add a circular constraint at the square's center
(ds:add-circ-cstrn dsmodel1 1 "position"
    (par-pos 0.5 0.5) (par-pos 0 0.3)
    (par-pos 0.3 0))
;; 7
; toggle off the default crv-cstrns
(ds:toggle-cstrn dsmodel1 1)
;; 0
(ds:toggle-cstrn dsmodel1 2)
;; 0
(ds:toggle-cstrn dsmodel1 3)
;; 6
(ds:toggle-cstrn dsmodel1 4)
;; 6
; Add a pt-cstrn at the center and track it
(define cc1 (ds:add-pt-cstrn dsmodel1 1
    "position" (par-pos 0.5 0.5)))
;; cc1
(ds:set-pt-xyz dsmodel1 cc1 0 (position 16 16 10))
;; 8
; Compute a new deformable model position
(ds:solve dsmodel1 1 1)
;; ()
; dsmodel1 deforms to interpolate
; both the point and the curve constraint.
; Commit the deformable surface back to the model.
(ds:commit dsmodel1)
;; ()
; Perform a zoom-all to see everything. This
; is part of acis.scm.
(zoom-all)
;; #[view 10768947]

[Top]

ds:crv-cstrn-from-load

Action
Converts a curve load into a curve constraint and returns the curve constraints tag.

Filename
scm/scmext/ds/dsscm.cpp

APIs
api_dm_get_attrib_dm2acis

Syntax
(ds:crv-cstrn-from-load owner tag memory=remember)

Arg Types
owner entity
tag integer
memory string

Returns
integer
Description
Converts a curve load into a curve constraint. tag defines the tag ID for the cstrn to be converted. memory can be "r" for remember or "f" for forget. Returns the tag identifier of the converted object.

The curve load is converted into a curve constraint, keeping the same tag ID and behaviors. When memory is remember, the constraint has the same target as the load. When memory is forget, the constraints target curve is generated by projecting the parameter space curve into image space through the surface function. In this case, the surface is constrained to maintain its current position all along the parameter space curve.

Arguments
owner ACIS face or edge on which the deformable model lives.

tag defines the tag ID for the cstrn to be converted.

memory is "r" for remember or "f" for forget.
; ds:crv-cstrn-from-load
; Add a crv-load which forces a line in a surface to
; lie near a 3-space line then convert it to a
; constraint.
; Build a test square spline face.
; (6x6 control points, x and y side length = 36)
(define dsmodel1 (ds:test-face 6 6 36 36 0))
;; dsmodel1
; Dont display entity / ds test face exists
(define erase (entity:erase dsmodel1))
;; erase
; Render the loads and constraints.
(ds:set-draw-state dsmodel1 1
    (+ ds-draw-cstrns ds-draw-loads))
;; ()
; Add a spline to a 3-space line crv-load
(define cc1 (ds:add-spring-curve dsmodel1 1
    (par-pos 0 0.5) (par-pos 0.5 0)
    (position 0 18 10) (position 18 0 20) 1000))
;; cc1
; toggle off the default crv-cstrns
(ds:toggle-cstrn dsmodel1 1)
;; 0
(ds:toggle-cstrn dsmodel1 2)
;; 0
(ds:toggle-cstrn dsmodel1 3)
;; 6
(ds:toggle-cstrn dsmodel1 4)
;; 6
; Add some corner point constraints
(define cc2 (ds:add-pt-cstrn dsmodel1 1
    "position" (par-pos 0 0)))
;; cc2
(ds:add-pt-cstrn dsmodel1 1
    "position" (par-pos 0 1))
;; 9
(ds:add-pt-cstrn dsmodel1 1
    "position" (par-pos 1 1))
;; 10
(ds:add-pt-cstrn dsmodel1 1
    "position" (par-pos 1 0))
;; 11
; Compute a new deformable model position
(ds:solve dsmodel1 1 1)
;; ()
; OUTPUT Original
; Convert the load to a constraint
(ds:crv-cstrn-from-load dsmodel1 cc1 "forget")
;; 7
; OUTPUT Result

Figure. ds:crv-cstrn-from-load

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ds:crv-load-from-cstrn

Action
Creates a curve load from a topological curve constraint or converts a user-added curve constraint into a curve load.

Filename
scm/scmext/ds/dsscm.cpp

APIs
api_dm_get_attrib_dm2acis

Syntax
(ds:crv-load-from-cstrn owner tag memory=remember)

Arg Types
owner entity
tag integer
memory string

Returns
integer
Description
Converts a curve constraint into a curve load. tag defines the tag ID for the cstrn to be converted. memory can be "r", "remember", "f", or "forget". Returns the tag identifier of the converted object.

When the constraint is user-added, it is converted into a curve load, keeping the same tag ID and behaviors. If it is a sheet boundary constraint, a new curve load is created and the constraint is disabled. The loads parameter space curve lying within the surface is taken from the curve constraints parameter space curve. If the curve constraint has a target and the memory argument is remember, the load has the same target as the constraint. Otherwise, the loads image space curve is generated by projecting the parameter space curve into image space through the surface function. In this case, the two curves of the curve load start out at the same location.

Arguments
owner ACIS face or edge on which the deformable model lives.

tag defines the tag ID for the cstrn to be converted.

memory is "r" for remember or "f" for forget.
; ds:crv-load-from-cstrn
; Builds a crv-load from a crv-cstrn.
; Returns the crv-cstrns tag.
; Build a test square face with some tag objects
; (6x6 control points, x and y side length = 36)
(define dsmodel1 (ds:test-face 6 6 36 36 0))
;; dsmodel1
; Dont display entity / ds test face exists
(define erase (entity:erase dsmodel1))
;; erase
; Render the loads and constraints.
(ds:set-draw-state dsmodel1 1
    (+ ds-draw-cstrns ds-draw-loads))
;; ()
; Add corner and center point constraints
(define cc1 (ds:add-pt-cstrn dsmodel1
    1 "position" (par-pos 0.5 0.5)))
;; cc1
(ds:add-pt-cstrn dsmodel1 1 "position"
    (par-pos 0 0))
;; 8
(ds:add-pt-cstrn dsmodel1 1 "position"
    (par-pos 1 0))
;; 9
(ds:add-pt-cstrn dsmodel1 1 "position"
    (par-pos 1 1))
;; 10
(ds:add-pt-cstrn dsmodel1 1 "position"
    (par-pos 0 1))
;; 11
; convert the edge constraints into edge loads
(ds:crv-load-from-cstrn dsmodel1 3 "forget")
;; 12
(ds:crv-load-from-cstrn dsmodel1 4 "forget")
;; 13
(ds:crv-load-from-cstrn dsmodel1 5 "f")
;; 14
(ds:set-pt-xyz dsmodel1 cc1 0
    (position 18 18 36))
;; 8
; OUTPUT Original
(ds:solve dsmodel1 1 1)
;; ()
; The edges of the curve move with the point
; but not as much as with no edge curve-loads
; OUTPUT Result

Figure. ds:crv-load-from-cstrn

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