Geometric Utility Functions
This topic documents some global utility functions for doing geometric computations.
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BaryCoords()- Given three points in 2D space (or 3D space) forming a triangle, and a fourth point in the plane of that triangle, this function returns the barycentric coordinates of that point relative to the triangle. Note: If the face (or set of 3 points) is degenerate, i.e. if it has a zero length normal vector ((p1-p0)^(p2-p0)), the methods return Point3(-1,1,1). -
RayHitsBox()- Returns TRUE if the specified ray intersects the specified box; otherwise FALSE. -
DistPtToLine()- Computes the distance of pointqfrom the line with endpointsp0andp1. -
Dist3DPtToLine()- Computes the distance of pointqfrom the line with endpointsp0andp1. -
ComputeBumpVectors()- Computes the 3 Bump basis vectors from the UVW's at the triangle. Takes as input the coordinates of triangle vertices (usually in camera space). The output is the 3 bump basis vectors (normalized) corresponding to the U,V,and W axes -
ComputeBumpVec2D()- Computes the 2 Bump basis vectors from the UV, VW, or WU at a triangle. The axis value is 0 for UV (AXIS_UV), 1 for VW (AXIS_VW), and 2 for WU (AXIS_WU). The output of this function are 2 bump basis vectors (normalized) corresponding to the specified axes. -
CompressNormal()- Compresses a unit vector from aPoint3to aULONGand returns it. Note that it is only accurate to 1 part in 512. -
DeCompressNormal()- Decompresses a unit vector into a Point3. -
ArbAxies()- This is used to come up with an arbitrary axis system given an "up" direction. This conforms to the AutoCAD algorithm.
