glass invisible in multipass masks

[visualtracing__]

Hi guys,

I can't find the option to make a glass invisible in multipass masks. Can someone help me?

thank you

[zhanet.georgieva]

Hi visualtracing__,

To make the glass invisible in the multipass masks, you'll want to tweak the settings in the Refraction Tab. Here's how you can do it:

1. Open the Refraction Tab of the glass material and go to Refraction Advanced.
2. Under "Affect Channels," you have three options:
   • Color Only: This will make the transparency affect only the RGB channel of the final render, keeping the alpha intact.
   • Color+alpha: Choose this option, and the material will transmit the alpha of the refracted objects, instead of displaying an opaque alpha.
   • All channels: If you select this, all channels and render elements will be affected by the transparency of the material.

Depending on your specific needs, you can choose the most suitable option from these three. Find the one that works best for your project.

Hope this helps, and if you have any more questions, don't hesitate to ask.

[visualtracing__]

I'll try to attach an example scene.
thank you all

[visualtracing__]

oh sorry, we responded to the post at the same time. I'll try right away, thanks

[visualtracing__]

Hi visualtracing__,

To make the glass invisible in the multipass masks, you'll want to tweak the settings in the Refraction Tab. Here's how you can do it:

1. Open the Refraction Tab of the glass material and go to Refraction Advanced.
2. Under "Affect Channels," you have three options:
   • Color Only: This will make the transparency affect only the RGB channel of the final render, keeping the alpha intact.
   • Color+alpha: Choose this option, and the material will transmit the alpha of the refracted objects, instead of displaying an opaque alpha.
   • All channels: If you select this, all channels and render elements will be affected by the transparency of the material.

Depending on your specific needs, you can choose the most suitable option from these three. Find the one that works best for your project.

Hope this helps, and if you have any more questions, don't hesitate to ask.

I tried but I always get this result

[zhanet.georgieva]

Hi visualtracing__,

I've reviewed your scene, and here's what I found:

1. For the Multi Matte Render Element, it wasn't appearing as expected because the settings for this RE weren't configured. You'll need to access the settings of this RE and specify how the mask should be generated. (V-Ray > Render Elements)
   You can find more information regarding Multi Matte RE here: https://docs.chaos.com/display/VC4D/Multi+Matte+RE
2. Regarding the Render ID RE and Object ID - No issues there. This is how these REs work.
3. As for the Cryptomatte RE, I understand it might be a bit confusing. The information about refraction is indeed present in this RE. If you save it as an EXR file, you should be able to see the transparency of the glass. Additionally, when using this RE as a mask in the VFB, it should produce the expected results with the glass transparency.

[visualtracing__]

Hi zhanet_georgieva,

thank you very much, sorry, I was used to it like in Corona where I excluded the glass from the render ID while in vray I see that it's a little different.
Thank you