PK_ERROR_code_t PK_VECTOR_make_view_transf ( --- received arguments --- PK_VECTOR1_t direct, --- direction(normalised) --- returned arguments --- PK_TRANSF_t *const transf --- viewing transformation ) This function accepts a PK_VECTOR1_t view direction and returns a viewing transform entity which incorporates this direction. This function accepts a normalised direction vector and creates a viewing transform entity from it with zero translation and perspective components, unit scale and a rotation sub matrix with determinant 1. The viewing matrix is right handed. The following table describes the view matrix in "column major" order (using the notation of the Parasolid Functional Description manual). [ Hi Vi Di Px=0.0 ] [ Hj Vj Dj Py=0.0 ] [ Hk Vk Dk Pz=0.0 ] [ Tx=0.0 Ty=0.0 Tz=0.0 Sc=1.0 ] The rotation sub matrix defines 3 three orthogonal axes H, V, D where D = -(direct) and V and H are calculated so that when D is parallel to a principal axis, these vectors will be parallel to the other two principal axes.