Vector Tsumuji

**Tsumuji = Hair Whorl























Image 1:
Function preparation for Tsumuji on surface. Among the point field, user can assign a center point (I call it Tsumuji point) so that all the other surrounding vectors will be effected.

1. Create direct vector from the center Pt to a target Pt.
2. VectorCrossProduct 1. and Z axis.
3. VectorAdd 2. and Z axis.

Keep the dblLength of 1, then use later to adjust the length of each vector according to how far a target point is from the Tsumuji point.

Image 2:
Applying the above function on surface normals.