Transparency inside volumes

[twistedpoly]

Hi,

at the moment I'm trying to figure out an issue or limitation, with using objects with transparency channel inside octane volume object.

Attached is the very simplified version of the problem, where you can still see 100% transparent plane inside volume. I've tried pretty much every option there is to fix this but can't find a solution.

My problem is basically trying to use objects with alpha/transparency channel inside volume object but doesn't seem to be usable for now.

Thanks,
Nejc

[bepeg4d]

Hi twistedpoly,
could you share an image of what do you want to obtain?
Which kernel are you using?
In the particular case, the plane is totaly invisible, not trasparent
ciao beppe

[twistedpoly]

thanks for your reply beppe.

So I'll try to simplify this even more for you.

What I'm trying to do it use image with an alpha on a plane inside volume object.

As you can see, alpha works well on image without volume.
On image with volume you can see the problem, visible plane borders that should be invisible. So that is my main problem, why is that border visible and how to get rid of that.

Let me know if this makes sense now.

Thanks,
Nejc

[bepeg4d]

Hi Nejc,
yes correct, there is an issue with alpha and volumes:

a workaround is to substitute the volumes objects with a normal cube and special specular material that mimics the fog effect:

The only disadvantage of this technique is that you cannot have the Camera inside the cube fog, otherwise the fog effect will not be visible.
ciao beppe

[twistedpoly]

thanks for clarifying beppe.

I see, I know about the workaround, only issue is that I'm not sure if I can use same 3d noise with it as with Volume object? Can you define different density based on a 3d noise inside the cube using this?

Thanks,
Nejc