Transparent object issue

[markus_s_cg]

Hi,

I'm trying to render a transparent object in front of a backplate (self illuminating geo with a mattepainting/photo), but I'm encountering black artifacts in the render.
The material opacity is set to 100% black, yet these artifacts persist, and they're also visible in the Alpha channel as black. The object consists of thousands of overlapping components with millions of polygons, so there’s significant overlap. While removing objects helps reduce the issue, it’s not a viable solution.

I’ve tried using a basic grey V-Ray material with a black color plugged into the opacity and tested all three opacity modes: stochastic, clip, and normal. Unfortunately, the problem remains.

I'm not sure what’s causing this or how to resolve it.

Here’s a link to the video: https://vimeo.com/1015645228

V-Ray version: 5.20.24

[vladimir_krastev]

Hi, thanks for posting. Have you tried to increase the Max transparency levels?

Is this a single render (no compositing) in video? How do you control the opacity to create this appearing/disappearing effect?

[markus_s_cg]

Thanks, I will try that!! I forgot that this was a setting. It's a single render, no compositing.

[markus_s_cg]

Hi, thanks for posting. Have you tried to increase the Max transparency levels?

Is this a single render (no compositing) in video? How do you control the opacity to create this appearing/disappearing effect?

Looks like you "hit the nail on the head!" Thank you!!

I control the opacity with a gradient map and UV mapping to reveal the object. That way it also works in the reflections and everything is done in one single renderpass. I only use AE for compositing the graphics on top.

[vladimir_krastev]

Great news! Thanks for the follow-up.