Vray 3 - Displacement 32bits + UDIMS + vrayHDRI = mini black seams

[olygraph]

Hi, I can't figure out how to remove these little black line seams from the render when I have diffenrent UDIMS and a 32 bits displacement on one character.

1. First of all, I created my maps in zbrush with the smooth uvs options on.. and with the exact same scale on each maps.
2. In the disp Modifier, I set the scale multiplier to 15 (my object scale) because it was scale and change the offset to : -1 x (scale / 2) so 15 and -7.5.
3. All my displace looks fine and have continuty on the edges but there is small black line between my uv seams.
4. When I lower the filtering on the vrayHDRI map the seams get smaller..
5. I can't lower the filter lower than 0.01 and there is no option to disable the filtering in the vrayHDRI map.

Is there another way to disable filtering for vrayHDRI maps?

Here are my settings. (Displacement quality does not fix the problem)

Click image for larger version.



Is there another to set up this to avoid theses seams?

Thanks!

[vlado]

Try setting also the interpolation to "bilinear" and see if it helps. Otherwise, we can probably add an option to turn off the filtering completely.

Best regards,
Vlado

[olygraph]

Umm bilinear filtering seems to give a very similar result. The seams is very very small tho. I wonder if it is really a filtering problem, but I guess an option to disable the filtering on this node could be a good addition.

Bilinear + Smaller edge pixels = way better but way longer render time and still a very small seams.

Thanks!

[vlado]

Ok. Do you think you can get me some part of that model for testing?

Best regards,
Vlado

[Nearl]

Has there been any progress on this? I've been dealing with the same issue for a while.

[vlado]

Nope, nothing new on that front for the moment (other than reducing filtering, that is). I know what I want to do about the issue, just need to find the time for it.

Best regards,
Vlado

[Nearl]

The filter texmap check box seems to not be functioning. I had just check it off to remove filtering, but it appears to still filter per the Filter blur value. If you set the Filter Blur to 0.0 then all of the displacement seam issues go away....don't trust the check box. Here are some quick examples...

[vlado]

Can you get me the scene for that?

Best regards,
Vlado

[Nearl]

We were able to reproduce the same effect in multiple scenes, fyi. Below is a link to a test scene.

http://www.trinityanimation.com/FTP/...um-DM-Test.zip

[Morbid Angel]

We were able to reproduce the same effect in multiple scenes, fyi. Below is a link to a test scene.

http://www.trinityanimation.com/FTP/...um-DM-Test.zip

I don't think there is anything that vray can do in your particular case Nearl. If you set the filter blur size to a low value like 0.05 the edges go away.

The issue is if you use adaptive uv tiles, the uvs are spaced very close to each other. So, there is no bleed area to allow for pixels in displacement map to bleed out after filtering is performed some of the values from adjacent uvs get sampled into the displacement.

[Pionier]

Hello,

just a quick question, It has been a while since I used vray but I need to use it again, I'm on version 3.30.05 now and I'm trying to apply 32 bit disp base on this tutorial: http://www.cggallery.com/tutorials/displacement/
We are doing disp in zbrush and I'm using vray for max.

Now, when I disable filter texmap in vraydisp mod - I get really ugly looking render, the very first thing I wanted to change to improve it was to lower Edge length, but this dosne't made any visual different to my render. Then I switch from 3D to Sub mode, but still nothing change. Lowering edge length to 1 and increase max subd still doesn't made a different.

Lowering blur in VrayHDRI map or using VraBmpFilter starts make visual different, however Edghe length sitll don't affect my renders (the only think that is affecting is render time). And, there are some "AA" artefacts on the disp.

is this normal or something has change since version hmm 2.x ?

Regards,
Peter.

[Morbid Angel]

can you show us examples? Generally displacement look quality depends on the resolution of the map and the resolution of the geometry its been generated from.

[Pionier]

sure,

here you have some screenshots,
I just have that feeling that lowering Edge length shoud make some difference on the render.
As for the map, this is 4k res map, ane there is a TS with 3/4 iterations before vrayDispMod.

Thanks,
Peter.

[Pionier]

another few, I will also check out how the model looks like in Zb tomorrow when my zb artist will be in the office

[Morbid Angel]

without seeing the actual scene + the map I can only guess that the map it self is too low res.