Anisotropy reflections issue.

[REDVERTEX]

Hi there!
We have a real pain. We use Vray 1.5 SP4a on 3DSmax2008 with all updates.
Anisotropy reflections on perfect geometry causes problem. The geometry was already checked for perfection. It is converted to EDIT MESH. The material renders perfectly without Anisotropy. But when the Anisotropy is set ON, we have this problem and cannot solve them. I already talked with Nikki Candelero and Zdravko form support, but still no solution.
We are looking for smooth material (brushed stainless steel) reflections, but when the reflection reaches a 100% planar zone, it produces an edge.
Here are some of the images illustrating the problem:

RENDERED IMAGE


BOX OBJECTS TRIANGLES


BOX OBJECTS TRIANGLES AFTER TURBO SMOOTH


ONE SMOOTHING GROUP

[vlado]

What should be the direction of the anisotropy on the flat surface? You can try to use a UVW map channel for the anisotropy direction, and use the UVW Mapping modifier to adjust that.

Best regards,
Vlado

[REDVERTEX]

Vlado,

thank you for the fast reply. The problem is, that the UVW map will help for that particular box, but it is not the real solution. It is because we have a hundreds of kitchen hoods with complex geometry. Trying to use different UVW map on every problem area and to adjust it manualy will take ages

As I see, probably this is known issue ?!?

We may continue rendering without anisotropy. The images still look good, but I want to try to fix this issue. It's much better when using anisotropy.

[vlado]

Right now, if you are using the "Map channel" UV vector derivation for the anisotropy, then the effect follows the object UV coordinates for the specified channel and if there are seams in it, there will be seams in the anisotropy as well. If you are using the "Local axis" option, then you will get issues on any faces are are strictly perpendicular to the chosen axis (e.g. if it is the Z axis, then any horizontal faces of your object have undefined anisotropy vectors, as V-Ray has no idea how to orient them).

What I can do, is make the anisotropy vectors on these faces circular around the object pivot... would that work?

Best regards,
Vlado

[REDVERTEX]

Vlado,

Thank you for your ideas.
We'll do some test renderings on your last tip and I'll post the results back here.

cheers,

[REDVERTEX]

Still no positive result. Here are more shots from the situation:


RAMP Map for aniso direction


RAMP Map for aniso direction - 2nd option


Z vector direction


NO anisotropy


GEOmetry

[3DMK]

Just remember also that you can't bend stainless steel sheets the way you have in the first render. There would be a join on one of the edges as it's almost impossible to bend it over 3 different angles/faces.

Cheers

[REDVERTEX]

3DMK,

Thank you for the reminder, but this is not the issue. It's about the material anisotropy.
The 1st set of renders is only an example box located in the camera FOV.

cheers

[vlado]

Can't say much about the last images without the scene, but what do you think of my question above? What would you like the anisotropy direction to be on the bottom face of the box?

Best regards,
Vlado

[trixian]

At least show the geometry with the anisotropic rotation map visible....no way of knowing what you have done...or post a part of the scene.