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Displacement misery

Posted: Sun Feb 12, 2012 5:07 pm
by garyswindell
I am trying to get a handle on mxm displacement scale in Sketchup.

In this test I am using the Soft Carpet mxm from the gallery
- http://resources.maxwellrender.com/download.php?id=3562

The tiling in the mxm is all set at X=1 Y=1 and real scale is turned off.

I import the MXM into sketchup and then apply the mxm texture to the sketchup material (from the Maxwell Scene Manager).

Shown here are the results when the material texture scale is set at 1m and 0.1cm. Wavy, bumpy, surface results in both cases.

I can understand on the 1M scale, but at the 0.1cm scale it makes no sense. It seems to scale the texture maps but not the displacement. ???

http://imageshack.us/photo/my-images/191/carpet1m.jpg/

http://imageshack.us/photo/my-images/27/carpet01cm.jpg/

Re: Displacement misery

Posted: Sun Feb 12, 2012 6:48 pm
by Half Life
Did you also change the scale for all the maps in MXED? The texture map looks scaled but you also have to scale the displacement map (as well as any others) to the same scale.

Best,
Jason.

Re: Displacement misery

Posted: Sun Feb 12, 2012 8:44 pm
by Half Life
OK, so I finally got back to the studio and was able to look at the MXM that you are using --the problem is one of precision.

What you need to do is set the displacements "subdivision" setting higher -- or simply use the adaptive setting (my preference).

But before you do that, make sure you understand something very basic for successful displacement in Maxwell -- the more subdivided the geometry you are applying the displacement material to is, the faster and better the material will render.

I prefer to use the SketchUp Sandbox tools to quickly generate highly subdivided planes for displacement materials... in this example I made a 1m x 1m plane with subdivision every .01m (I did say highly subdivided :wink: )... then I smoothed the co-planar edges and applied the SketchUp material I made.
softcarpet.png
I set the displacement for adaptive at 1cm with the offset at 0.5 --therefor in SketchUp I also dropped the ground plane to -0.005m.

This combination of settings allows for very fine detail that renders fairly quickly (this render took about 9 minutes) at the cost of a geometrically heavy SketchUp file.

Best,
Jason.

Re: Displacement misery

Posted: Mon Feb 13, 2012 2:30 am
by garyswindell
I appreciate the pointers. This advice will assist me greatly.