Another 'zbrush to octane displacement problem' post

[cristiangiro]

Hi,
it's been months of research of a workflow that works and every time i give up octane and render with modo.
I still can't figure it out how to make a zbrush displacement work into octane, and it's disappointing.
In the joined picture you can see the same render with modo and the other with octane.

the displacement map is a 32bit exr with mid value of 0
the ray epsilon in octane is of 1 um
i'm running octane 3
i have the same problem with octane on cinema 4d

do we have a known solution for this problem?

[face_off]

Hi - are you able to provide the scene pls? Then I can submit it to Otoy to get a response. Also, have you tried using the Render Cache displacement mapping with the OctaneRender for Modo plugin?

Paul

[cristiangiro]

Do you mean activating the "use modo render cache" in the octane preferences?
if yes, yes it's enabled
i'm uploading the scene for you

[face_off]

The Octane displacement mapping is indeed producing artifacts. I have uploaded the scene to Otoy, who can investigate further.

You can use Modo displacement by a) ticking Preferences->Rendering->Octane->Use Modo Render Cache and b) ticking Kernel->Setting->Polygon Displacement. This will ignore the displacement map in Modo, and will instead use the micro-polys generated by the Modo renderer. Unfortunately I ran out of memory on my 16GB Windows PC doing this, but you might have better hardware. You can reduce the tessellation rate of the displacement polys via the Renderer->Settings->Geometry settings - but I don't know enough about those settings to get it working.

You could also try scaling the geometry 100x if the cause of the problem is the ray epsilon.

Paul

[gordonrobb]

Been waiting for Otoy to do something about this for a while in standalone. Frustrating as hell.

[cristiangiro]

Yeah, it's not like a 'niche' thing, displacement is quite fundamental and it's been really surprising to see very old posts about this problem that keep coming back after ages with no solution...

[voto1979]

Hi, I know that I can use the Modo internal displacement map!
But with the Octane displacement node in Modo I get some strange results (artefact's in form of polygons).

You can see sort of a polygonal or chase pattern! Is this know?
With the Modo displacement map I don't get this?

[face_off]

Hi, I know that I can use the Modo internal displacement map!
But with the Octane displacement node in Modo I get some strange results (artefact's in form of polygons).

You can see sort of a polygonal or chase pattern! Is this know?
With the Modo displacement map I don't get this?

This occurs when you have very long, thin triangles with a displacement map applied. It /may/ be improved with release 3.04.2 (since there have been some tweaks to displacement map rendering). But removing the long, thin triangles is worth a try too.

You can test with the pre-release of the 3.04.2 version of the Modo plugin at https://render.otoy.com/customerdownloa ... _64bit.exe.

Paul

[voto1979]

thanks for the quick answer ... I will test the new plugin!