VRayLightMtl and alpha

[YoyoBoy]

Is it a bug that the VRayLightMtl can't access an image alpha like the VRayMtl can? See the attached image to understand what I'm talking about. Is the only way around this to make a copy of the bitmap loader and switch the RGB output to alpha?

[hermit.crab]

Have you checked the "Multiply color by opacity" option in the VRayLightMtl?

[YoyoBoy]

Yes, I have that checked. And it doesn't seem to matter if my file is a PNG or a flattened TIF with an alpha channel.

[hermit.crab]

Do attach (or send) the scene so we can take a look. Mention your V-Ray and host platform versions as well.

[YoyoBoy]

Sure. Scene attached. CutoutTest-1.zip

Oh, and it's Max 2024 and VRay Update6 1.2

[hermit.crab]

I see, my test was a bad one since I used a black-and-white image... Thank you for the report. It seems the VRayLightMtl reads the RGB output only. I've logged it (internal bug-tracker id: VMAX-13368 ) for dev investigation. For now, duplicate the bitmap and set the RGB output to Alpha as Grey.