I have some problems with Particles and opacity in 3DS Max 2020, Vray 5 (1.3)

[harald_martinoff]

Hi all.

I m back to Vray after awhile and testing Vray 5 (1.3) with Max 2020 and working on a subsea scene. See image. I like to have some particles float around like "fluffy" debris, but I have problem getting the opacity map work on the camera facing 2D particles when I combine it with the VrayEnvironmentfog. I also use some normal standard Volume fog on gizmos, but they don't create any problem. In the second image (only fog and particles) I have scaled the particles up so you can see the problem (the particle square is showing. Opacity map is desaturated and the black part is fully black. Yes it is a low resolution render.). I have been searching online and I have done this before, but now I m suddenly stuck. Can anyone point me in the direction for of to make the opacity map work with VrayEnvironmentFog. I also added a screen shot of the particles setup/material setup. Everything is just a simple, but I do something wrong

Br Harald Martinoff

[fixeighted]

It all works as expected using Max 22. Have you tried using a checker map to check this?

[harald_martinoff]

Hi. Yes I have tried the checker and it is the same. Black doesn't create fully transparency, in combination with the VrayEnvironmentFog. I will work on and see if I can manage to fix it

[fixeighted]

You can post your (stripped down ofc) scene if you like, and I or others can check it to see if it works, as there is no problem, as I mentioned, with the setup I have.

[hermit.crab]

Do you have by any chance a VRayAerialPerspective active? There is a known issue with Aerial perspective and opacity mapped objects. If not, do send the scene via the contact form so we can take a look. Mention me and include a link to this thread in the message.

[harald_martinoff]

Hi. Thanks for answering. I used some time to check and re-check, but I m still having problems when I have two or more fog-systems in the same scene. I attach a simple scene (Max 2020, Vray 5, 1.3) with one particle system with facing particles and a material with an opacity map. It has two Vray fog-systems. One VrayEnvironmentFog normal system and one VrayEnvironmentFog with a Gizmo. Some descriptions in the images.
Test-fog-particles.zip

[fixeighted]

It seems that if you move the one with the gizmo up in the list then it will work...well, as you see in this image there is one that doesn't, for whatever reason..maybe I made a tweak too far as I was testing it

[harald_martinoff]

Oh... what? I didn't know there was some kind of order of things when it comes to the fogs! If this fix it then, but of course there is one, as you said, that still keep the full particle "plane" visible. Basically it shouldn't be a problem at all to mix fogs and then use opacity map. Maybe someone else have an answer, but .I see now that Chaos support also want to check. If anybody knows it will be them Thank you so much

[fixeighted]

Yes the order makes a difference with some stuff apparently.
It is odd that there is just that one that is not resolving, so maybe devs have an insight to that
I've got renders going now but might have another look in the morning....maybe it actually was something that I changed whilst testing, unless it shows in any of yours of course.

[hermit.crab]

The issue is still there, though not as visible when reordering the fogs. I've logged it (internal bug-tracker id: VMAX-11397) for developer investigation. A workaround may be rendering the overall fog separately through a VRayAtmosphere element and later apply it in comp.

[harald_martinoff]

Thanks! I will do the separation and apply through comp for now I also made a ticket on it (#3814) before I saw your answer