Displacement artifacts with procedural textures (3D and Subdiv displacement)

[insanetk]

(using VRay 2.30.01 and 3ds Max 2013 64bit)

I'm getting some odd displacement artifacts along the outline of some mountains I'm working on. I'm using VrayDisplacementMod with subdivision displacement. The same artifacts appear in 3D mapping displacement. The problem seems to appear whenever there is a strong outline (visible edge) from the view of the model. I'm not sure what causes this, but it looks like VRay seems to not keep form continuity around the outline (visible edge), yet the model is one whole mesh and I do have keep continuity on just in case. The scale of the scene is in meters and the mountain is approximately 1000 meters wide and 500 tall, and centered in 3Ds max, so scale shouldn't be an issue I think.

The displacement texture is made of procedural textures, mainly bercon maps. But these same problems arise with regular 3ds max procedural as well, like cellular.



update:



In this render the model seem to peel open almost.

[Macker]

Adjust the "edge threshold" until it fixes the problem. It's pretty much the same as a vertex weld afaik. It's a radius that specifies how close/far things have to be for the seam to be kept continuous.

[insanetk]

Adjust the "edge threshold" until it fixes the problem. It's pretty much the same as a vertex weld afaik. It's a radius that specifies how close/far things have to be for the seam to be kept continuous.

I've rendered with 0,5 in edge threshold which is the highest VRay allows me to set it to, and i still get these broken splits. Nothing changes visually. On top of that the splits happen regardless of how low or high the displacement amount is set to, but the amount it is splitting apart is proportional to the amount the displacement is. It is view dependent, so if I render the broken region from another angle it is fine, artifacts appear along other outlines instead. I almost get a feeling that VRay doesn't look "around" the model properly when displacing it since it is messing up the displacement exactly where the contour is starting based on the cameras point of view.

[Macker]

Have you tried 3D mapping, rather than subdivision? I can honestly say I've never needed to use the subdivision feature.

[insanetk]

Have you tried 3D mapping, rather than subdivision? I can honestly say I've never needed to use the subdivision feature.

It happens with 3D mapping as well. Creates exactly the same result.

[Dariusz Makowski (Dadal)]

Vertexes arent merged or something like that ?

[vlado]

It looks like the textures don't blend seamlessly, for whatever reason the displacement values on one side of a split are different from the values on the other side.

Are you trying to combine multiple texture tiles into one texture with the Composite map?

Best regards,
Vlado

[insanetk]

It looks like the textures don't blend seamlessly, for whatever reason the displacement values on one side of a split are different from the values on the other side.

Are you trying to combine multiple texture tiles into one texture with the Composite map?

Best regards,
Vlado

I'm combining several procedural textures with the composite map.

EDIT: I am suspecting that the fall-off procedural I'm using to mask two different procedurals might cause some of the problem.

[Dariusz Makowski (Dadal)]

If I remember correctly remember that 3ds max standard procedural files are 8 bit... Use bercon as they are 16 or 32 I cant remember...

[insanetk]

I've made a quick animation where i use a Falloff in local Z-axis as displacement. This provokes the artifact in the displacement.

This is with 3D mapping. Same result would happen with subdivision as well.

[svetlozar.draganov]

Hello insanetk

Is it possible to attach the scene used in your animation?
Thank you very much in advance.

[insanetk]

Hello insanetk

Is it possible to attach the scene used in your animation?
Thank you very much in advance.

Here it is: https://docs.google.com/open?id=0B95...XRYX0lCb0lKNFk

Click file -> download

[insanetk]

I really need a fix on this by Monday, would really appreciate if someone could really look into this. In case the previous link didn't work for you. https://dl.dropbox.com/u/55232501/3d...ment_bug01.max


Update: I've tested with berconmaps own gradient falloff, creates the same result as 3Ds Max default falloff map.

[vlado]

Well, I can reproduce the issue here; looking into it now... it looks like a bug and I don't know how long it will take me to fix it, but for the moment it works fine if I bake the falloff map into an .exr texture and use that instead.

Best regards,
Vlado

[insanetk]

Well, I can reproduce the issue here; looking into it now... it looks like a bug and I don't know how long it will take me to fix it, but for the moment it works fine if I bake the falloff map into an .exr texture and use that instead.

Best regards,
Vlado

Thanks Vlado, I'm gonna use the EXR baking technique for now. Hope you get it fixed soon!