AnisotropicFun – part1

the following are the pics I created after a few days test session around anisotropy and specifically anisotropic reflections.
these two links from Neil Blevins helped a lot clarifying the subject :
Anisotropic Reflections tutorial
Anisotropic Highlights tutorial

I was looking for a way to synchronize the derivative vectors orientation/patterns and the texture maps used for bump or diffuse to help in the final shading of these kind of materials.
I came up with this idea to use the derivative vectors to drive a 2D directional blur.

Shading is done in XSI/MentalRay using MR physics lib (dgs or mib_glossy_reflection).
All these tests have been done with version 5 of XSI.
Directional Blur is done with ReVisionFX’s RSMBVector inside XSI FXtree.

NoAnisotropy

derivative vectors are defined using the deriver shader. here north pole at (0,0,0)

clean UVs

rendermapping U derivative vector : this is done using a special VectorState shader and applied as the color of the object . this is rendermapped as a .ct texture to keep negative informations intact.

transforming the derivative in the UVbasis : the rendermapped derivative is injected in the bump map slot of the material.

than everything is rendermapped again using rendermap option to render normals in the UVbasis.

if you get rid of the blue component it looks like a typical RSMB vectormap input.

visualising the vectors with lmVectorViewer

creating a noise pattern

applying directional blur with RSMB

using the map in bump and diffuse shaders

part2