Hello,
I was trying different settings with standard scenes.
Opacity maps seem not to work.
I toggled also “Opacity Maps” in the render settings.
Attached a screenshot from street lamps
Thanks for looking
We support only the “clip” opacity mode, so a particular pixel can be only fully transparent or fully opaque.
I know the scene you’ve posted the screen-shot from, and this is a V-Ray Light material, which doesn’t use “clip” opacity.
I just tried it, and for this opacity texture, the clip mode doesn’t really work, all pixels are <128 so they are all considered fully transparent.
We might support the other opacity modes in the future, which will enable us to support the V-Ray Light material’s opacity.
Greetings,
Vladimir Nedev
Hello,
I have the same problem with “fire” material made with VraylightMtl + Opacity map. Work great on 3DS MAX 2021 + Vray 5 but dont work on Project Lavina 
Maybe you can use textured refraction color instead ?
Greetings,
Vladimir Nedev
Is it possible to use opacity map in vrayligthmaterial? I tried here and it didn’t work
Dear All,
I’d like to share a quick workaround on this topic.
We use trees all the time in Vantage, and most of the models out there have opacity maps on their leaves. The following is true for 3DSMax users, but I’m sure that the same logic can be applied to all software that supports Vray or Vantage.
What we are doing is:
- The opacity map is connected to the output node.
- We invert the map using the output node.
- We add the new inverted opacity map to the Vray Mtl - Refraction slot.
- We make sure the Refraction Glossy is set to 1.
- We change the Refraction IOR to 1.00.
This way, the Refraction is basically 1:1 to Opacity, but Vantage can understand the gradients and render the leaves properly.
We use trees all the time in Vantage, and most of the models out there have opacity maps on their leaves. The following is true for 3DSMax users, but I’m sure that the same logic can be applied to all software that supports Vray or Vantage.
You don’t have to do all of this for leaves, you can just enable “clip opacity”, since the leaf cutout texture is a black and white texture.
By using the refraction slot you are most likely making the rendering slower.
Greetings,
Vladimir Nedev
Where is clip opacity?
FOUND IT! Advanced setting.
HI Vladimir,
I am just checking that the latest Vantage still only supports the “clip” opacity mode, so a particular pixel can be only fully transparent or fully opaque and no intermediates options are yet supported.
If this is the case when might Vantage support the other opacity modes in the future? I’m looking to place an image sequence of steam rising on simple 2D plane located directly above a saucepan for an kitchen animation shot that I am working on.
Any update would be be greatly appreciated
Kind Regards
Josh
Hi Josh,
Adding support for full opacity support is in the future plans but cannot give an ETA. Until then you could go with the workaround to use refraction instead of opacity: https://drive.google.com/file/d/1J-BfvVq27x1KmFQytE3WndyStvJD8pby/view?usp=sharing The downside using this is that you can not use self-illumination to boost the smoke a bit. Let me know if this workflow works for in your case.
Best regards,
Alexander
Hi @Alexander.Atanasov there are more issues than just that with the current workaround.
One issue with the refraction workaround for opacity maps is that it can produce artifacts, likely due to the amount of bounces Vantage does with refractions… For example, a model from Character Creator, the characters hair uses opacity maps, as you move around the character in the scene it can produce black patches across the hair blades and that will change depending on the viewing angle this is with IOR set to 1 on refraction
And another one is that it doesn’t play well with overlapping meshes. Again on a character model coming out of Character Creator you need an opacity map on the scalp to blend in with the head and with the current workaround it produces an unwanted glare and an outline of the mesh that you otherwise would not get with a proper opacity map.
Another one is when used in conjunction with scattering fog and let’s say you have a large plane that you are adding a fog/cloud sprite too. Currently scattering fog has an issue when you turn on Affecting Secondary Rays which I’ve gone into detail on another post here https://forums.chaos.com/forum/chaos…-or-refraction
Personally, I think having the option to switch between clip and full mode in Vantage would be the easiest change/addition. That way if you are in control of whether you take the small performance hit for the sake of rendering things as they should be rendered…
Thanks
Hi vasile_bulgac1,
Can you check again to see if it works now?
https://drive.google.com/file/d/1J-B…ew?usp=sharing
Hi rita_sobral,
Again on a character model coming out of Character Creator you need an opacity map on the scalp to blend in with the head and with the current workaround it produces an unwanted glare and an outline of the mesh.
Can you please share a screenshot and material setup with that issue?
Best regards,
Alexander
One issue with the refraction workaround for opacity maps is that it can produce artifacts, likely due to the amount of bounces Vantage does with refractions… For example, a model from Character Creator, the characters hair uses opacity maps, as you move around the character in the scene it can produce black patches across the hair blades and that will change depending on the viewing angle this is with IOR set to 1 on refraction
The “full” opacity mode when implemented will have the same limitation in terms of number of bounces as refraction.
The “clip” opacity can be implemented at a lower level where ray/triangle intersections are being determined, but the same cannot happen with the “full” opacity.
Of course, we can have a separate “max opacity depth” parameter, but this will likely have an even bigger performance impact.
That way if you are in control of whether you take the small performance hit for the sake of rendering things as they should be rendered…
It’s not a given that switching to “full” opacity will have a “small” performance hit.
Especially if you have trees/vegetation in your scene that require only “clip” opacity, but their V-Ray material is not setup properly and they actually use “full” opacity.
Greetings,
Vladimir Nedev
“Full” would probably look worse in interactive mode when moving (Optix denoiser) or when using DLSS, because of increased noise. That’s what the option would be useful for, of course.
Here are some screenshots of the issue with the scalp on a character from Character Creator. I tried the same shader setup on vray gpu, and vray gpu does not have the issue that Vantage does with the same shader? I think it has something to do with reflections, maybe reflection bounces? Not sure…
Both of these are using the opacity map inverted in the refraction with IOR set to 1. If I disable reflections in Vantage using the global setting then you cannot see the outline.
Also included a couple of hair examples.
I can work around the above issues for now but the one I can’t work around is the scattering fog issue as the Affect Secondary Rays option is not working as it should when compared to Vray GPU.
Thanks
Tom
Can you send us the scene with this character (with materials and textures) ?
Greetings,
Vladimir Nedev