(Open) [HOU-4616] Opacity Maps are culling geometries when using GPU or RTX

V-Ray for Houdini V-Ray for Houdini :: Issues
, , ,
1

scene setup like this: I have copied bunch no thickness planes in front of a thickness geometry, but they were no interactive.

When I use GPU engine render, Or RTX engine render, I got this result:

​

image.jpg
image.jpg2139×1126 349 KB

planes are culling geometry that below them. No intersection with each other:

image.jpg
image.jpg1472×1048 173 KB
​

When I switch to CPU engine, Everything is fine:

image.jpg
image.jpg2139×1126 400 KB

And CPU mode does not work like GPU mode when using “setprimintrinsic” VEX function, base on result, GPU mode works as expected, And CPU mode looks like have some bugs. (Animation of leaves would delay lots of time), But when I open another houdini and load those files I saved in disk before, It works fine.. Strange behavior.
CPU mode would showing this warning, and GPU mode would not:

image.png
image.png367×354 32.1 KB
​

2

Hi @leo_bao Thank you for sharing this with us! Could you please confirm if this happen only in this scene with this geometry or there are other scenarios as well?

What’re the versions of Houdini ( Help > About Houdini ) and V-Ray ( V-Ray > About V-Ray ) that you are using?

What are your GPU drivers?

Do you get the same results with CUDA and RTX?

Is it correct to understand that there is a material applied on the geometry? If you remove it, will the issue disappear?

3

@viktor_angelov ​
Could you please confirm if this happen only in this scene with this geometry or there are other scenarios as well?
Other scene also happened. When they did not cross each other, Geometry generated by this node “quixel_atlas_splitter” would cause culling (GPU mode, Both CUDA and RTX):

image.png

image.jpg
image.jpg4188×1078 325 KB
​
CPU is fine:

image.jpg
image.jpg4422×1087 327 KB
​
When they crossed each other(no “quixel_atlas_splitter” node), GPU mode(Both CUDA and RTX) would cause culling:

image.jpg
image.jpg3916×1162 397 KB

CPU mode would not:

image.jpg
image.jpg3877×1088 350 KB
​
What’re the versions of Houdini ( Help > About Houdini ) and V-Ray ( V-Ray > About V-Ray ) that you are using?​
20.5.445, 6.20.25

What are your GPU drivers?
566.36 Both Game Ready and Studio Driver - WHQL have been tested
566.14 Studio Driver - WHQL has been tested

Do you get the same results with CUDA and RTX?
Same

Is it correct to understand that there is a material applied on the geometry? If you remove it, will the issue disappear?
There is only a default vray material with an opacity texture applied on the geometry. I can’t remove it, I have to connect an opacity texture to get it work.​

4

And vray GPU for 3ds Max 2025 doesn’t have this problem though
​

image.jpg
image.jpg4174×1115 617 KB
​

5

Hi @leo_bao We are currently investigating the matter, however, it would be useful if you could share the scene with us so we can look into it.

Please, use V-Ray > Pack Scene

6

@viktor_angelov Here you go. If you need “quixel_atlas_splitter” node for debugging, please download it from here Quixel

image.png
image.png1817×437 15 KB
​
VRAY_RFE.rar (1.49 MB)

7

@viktor_angelov I have tested latest build: 6.20.25 0acf306_22839. But BUG still remains.

8

Hi @leo_bao We managed to reproduce the issue. I have discussed it with the team and will log it into our system for future resolution. I will reach out if I have more information on the matter.

Thank you for taking the time to share this with us!

9

Hello @leo_bao We have logged it into our system [HOU-4616​] and will be looking into it.

10

Hi @viktor_angelov i am looking forward to it, hope next stable build could fix it.

11

Has been at least a year, still not fixed.