anisotropy problem

[Lucas van Rossum]

Hi 

 

I have some artefacts when i render polygon with anisotropic materials.

My polygon have Uv and my tangent style is set to computeUV in the surface model.

 

If i subdivide the the mesh or if i check  "render polygon as subdivision" it work.

But i want  to keep my low poly mesh.

cheers

 

lucas

 

 

testAni.hip

[davpe]

you can try larger smoothing angle for vertices (vertex SOP). but I think with low poly mesh like this and raytracing you will allways get this kind of look. technically it is not an artifact. it is a correct rendering of the mesh that happens to be too low poly.

 

you could create your own custom shader (videogame like kind of shader) that is intepolating just a few samples, therefore giving smoothed out result (with less accuracy of course). not sure how technically challenging would that be though...

[Lucas van Rossum]

thank you , i will try to interpolate the uv in the shader.

cheers

[fathom]

i think your tangents are faceted.  rather than computing from uv, compute tangent and binormal in a polyframe sop and pull them into your shader.  transform them into current space, normalize them, and push them into the utan/vtan parms on your surface and select the tangent style "from connected source" (or whatever it's called).  see if that works.