Help with rendering vector displacement on a multij uv tiled object!

[radcliffe.chris]

I successfully rendered a vector displacement map out of Zbrush. Its a simple horn with some interesting details and curvature. I am able to render the single 0 to 1 uv'd horn, but when I tested multi-uv's on the same mesh, the result was unexpected!

I used the same exact settings out of Zbrush for the multi-tile object and it gave different unwanted results. It almost looks like the multi-tile vector displacement values are being clamped somehow. I'm trying to pinpoint whether it is zbrush or vray rendering the maps incorrectly.

[IMG][/IMG]

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[Mihail.Djurev]

Would it be possible for you to send us the scene with the texture, so we can see what's going on?
You can either post it here on the forum, or send it to support @ chaosgroup.com with a link to this thread for reference.

[radcliffe.chris]

Of course! I have emailed a zip file with the scene file, all the geometry, and the maps in corresponding folders for displacing. Thanks in advance!
Just emailed in to the support @ chaosgroup.com!

[Morbid Angel]

The issue is clipping bounds of the displacement. By default vray uses automatic clipping to determine where the min / max values of the displacement map are. However when you use 32 bit float exr especially mip mapped exr, you need to manually specify the clipping boundary. By default the manual clipping boundary is 0/1, however in a float image there is both negative and positive value, so I would set the clipping boundary to manual and set min value to 1- and max to 1 and see if you get the proper result.

[radcliffe.chris]

Awesome! Thats exactly what it was! Thanks Dmitry!