Hello,

I am using the H10 default ‘Glass’ shader to render some underwater metaball bubbles but keep getting these black artifacts on many of them.
(see picture)
I don't get them with the ‘basic surface’ shader.
The bubbles are made of metaballs copied onto particles.

Does anyone know what is causing the black spots or how I can get rid of them?

cheers
fred

I have just noticed what seems to be the problem. But I still don't understand why!?

I have one popnet that ‘outputs’ two particle groups.
On one group i Copy spheres, on the other I Copy metaballs.
These Copy nodes are then combined with an ‘Object Merge’ group. This is inside a Geometry node.
To this geometry node I attach the glass shader.

When I disable the ‘spheres’ part in the Object Merge node, the metaballs on their own render fine.
When both are enabled I get the black spots on the metaballs.


Does anyone know why this happens?


cheers
fred