Forest invisible to camera

[pingus]

Hello
We have a problem rendering Forest invisible to camera.

It's pretty easy to reproduce, a simple teapot in a Forest and put it invisible to cam.
Changing Max Transparency Levels off course resolve partially the problem (if you don't have too munch objects in the forest) but increase drastically the render times...

Collapsing the forest in objets revolve totally the problem.
So i tough it was a Forest bug so i reported it : https://forum.itoosoft.com/forest-pr...l-render-bits/
But it seems vray handle Forest object differently.

Confirmed with 2 pipelines : 3dsmax 2021 & Forest 6 and 3dsmax 2022 & Forest 7.4.1

That's a damn bug we face on every productions.
Could be cool to find a fix or workaround one day

Thanks !
-p-

[hermit.crab]

Maybe this thread will clear things up?

[pingus]

Indeed it's the same problem, and the answer is still the same : increase max transp. level and render time.

The fact is, with a teapot forest i don't have any opacity maps, and if i collapse forest into object, i don't have the problem.

So i still think there's a difference of treatment between standards objects and forest

[Morne]

Indeed it's the same problem, and the answer is still the same : increase max transp. level and render time.

The fact is, with a teapot forest i don't have any opacity maps, and if i collapse forest into object, i don't have the problem.

So i still think there's a difference of treatment between standards objects and forest

Yes this also suggest to me the issue lies in the VRay code hermit.crab

[hermit.crab]

Indeed it's the same problem, and the answer is still the same : increase max transp. level and render time.

The fact is, with a teapot forest i don't have any opacity maps, and if i collapse forest into object, i don't have the problem.

So i still think there's a difference of treatment between standards objects and forest

Try disabling the forest's "cast shadows" option as well.

[pingus]

- Disabling 'fake forest' option in Forest, doesn't change anything.
- Disabling object properties > cast shadow doesn't work. I don't have any shadows and alpha is still cropped

[hermit.crab]

Could you attach the scene from the screencap here? Also, share your V-Ray version build.

[pingus]

I've recreated the scene. (simple forest of teapot, change forest properties to invisible to cam)
I've also down the max transparent level to 30, just to make the problem more visible, but i confirm that even with 80 or 100 problem is still (but less) visible, and just longer to render.

Confirmed with
- 3dsmax 2021, Forest 6 and Vray 4.30.03
- 3dsmax 2022, Forest 7.4.1 and vray 5.20.03

[pingus]

For science, i've tested with 3ds2023 & vray 6 with the new scatter tool.
If i change the scatter objet to invis to cam, it doesn't change anything
But if i change the object that is scattered it works !

[hermit.crab]

Just so you know, we're investigating the matter. We've contacted iToo as well. For now, you may either increase the max. transp. levels or use VRayScatter as a workaround.