User's Manual

Bounding Volumes
187
• A csVec3f::xformPt(const csVec3f& v, const csMatrix4f& m) transform vector sets a
csVec3f vector, v, to be the first three components of (v,1) * m where v is treated as a
row vector.
• A csVec3f::xformVec(const csVec3f& v, const csMatrix4f& m) transform point sets
this vector to be v, thought of as a row vector, times the 3X3 submatrix formed by
the first 3 rows and first three columns of m. This is most useful for non-projective
transformations.
Bounding Volumes
Bounding volumes provide an efficient means of determining which shapes are in and
out of the view frustum. The bounding volume for all csNodes is a sphere, as shown in
Figure A-1.
Figure A-1 Bounding Sphere