I’m doing a fluid sim using the mantaflow beta version of Blender. It works perfectly using a Principled BSDF, but as soon as I plug in a Principled Volume node, it turns invisible. I tried switching between CPU rendering, CUDA, and OPTIX. No changes. The volumetrics will render just fine on other objects, but not my fluid mesh.
Anybody have any ideas why this might be?
Is the fluid mesh a closed surface? Or is there some bug in surface generation with Mantaflow. There being no other surface to hit after passing through a volume, is the most likely cause for volume shaders not working.
It appears to be a closed surface, but I’m not sure how to check that properly. Refraction seems to work when the Principled BSDF is plugged in.
It is not important that the surface is watertight (no pun intented), just that the place where the ray leaves the volume has a surface.
Can you post a blend file for the case where it is not working?
