Strange Displacement issue

V-Ray V-Ray for 3ds Max Issues
1

Hey guys,

I am having a very strange issue with displacement. I have a plane that i’m trying to displace grass on, it has a turbosmooth modifier on it (so plenty of geometry for VRay to work with) and has a UVW map - but I keep getting these strange light/dark bands.

The displacement map is a simple jpeg with noise.

It’s not down to mapping, but does shift around to produce a different pattern (though just as noticable) when I turn turbosmooth off. Even taking the Edge Length setting down to 1 pixel doesn’t fix it, if anything it makes it more prominent. Strangely the noise modifier in max also produces similar results, suggesting that it may not be VRay… Really stuck for ideas here!

It’s not normals either, just checked.

displ.jpg
displ.jpg817×612 211 KB

2

looks like youve got double faces to me.

3

I wish.

Checked that, no double faces. :frowning:

4

Check this out, just turned on wireframe mode and upped the iterations on turbosmooth massively, and it has recreated the effect in the viewport…

So it appears that the turbosmooth modifier isn’t subdividing everything? Only certain parts?

Swapped to a meshsmooth modifier instead and seems to be working in the viewport, however the proof is in the render…

Displ2.jpg
Displ2.jpg944×530 218 KB

5

use subdivide instead of turbosmooth.. that will give you even subdivision across the surface. turbosmooth and meshsmooth will always subdivide larger polys less finely than small ones.