Offsetting
New wires or faces can be created by offsetting from a reference wire body or face. Laws may be used for offsetting.
Figure. Offsetting
The Offsetting Component (OFST), provides the tools for creating new wires or faces that have been offset in some manner from a reference wire body or face. OFST incorporates ACIS laws to permit nonlinear and nonplanar offsetting, and provides APIs for offsetting: api_offset_planar_wire and api_offset_face.
Topics include:
Wire Offsetting
The function api_offset_planar_wire and the Scheme extension wire-body:offset are provided for wire offsetting. The API is overloaded. One version takes a multi-wire body input, another takes a single wire input, and another allows specification of the gap fill type as well as the use of laws for specifying the offset.
Wire Offsetting Gap Fill Type
If the offsets of adjacent, nontangential wire edges do not touch at a common vertex, the gap can be filled using several gap fill types. The extended type linearly extends the offset curves along their tangents until they intersect (creates a corner). The round type connects the endpoints with a tangential arc. The natural extension type extends the curves using curvature extension rather than linear extension. Refer to the following figure.
Figure. Gap Fill Types
Wire Offsetting with Laws
If laws are used for wire offsetting, the wire is offset by the given law and trimmed for self-intersections. If a nonzero twist law is given, then the resulting wire will twist around the given wire and trimming will not be done. The offset direction is given by the cross product of the wire's tangent and the planar normal. If a twist law is given, then the twist starts in the offset direction and rotates around the wire by the given radians of the twist law (using the right hand rule). A negative offset twists in the opposite direction. The function expects a body containing at least one independent wire (not connected to any faces). If the body contains multiple independent wires, each independent wire in the body will be offset and united with the offsets of the others.
Face Offsetting
The function api_offset_face is provided for face offsetting, and the Scheme extension face:offset can also be used. They create a face whose surface is offset from a given face. The edges of the new face are offset by a specified distance from the edges of the given face.
Scheme Example
; face:offset ; Create a face. (define face1 (face:plane (position 0 0 0) 30 30)) ;; face1 ; Create a face offset. (define offset1 (face:offset face1 5)) ;; offset1 ; OUTPUT Example |
Figure. face:offset
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