The GPU preview doesn’t properly draw above objects in the 3DS Max viewport. It seems to always draw below/under objects regardless of the angle it’s viewed - this must be because the viewport doesn’t also use the GPU so perhaps there is a way to get a representation of objects in the GPU preview. Even just some voxels to represent the object would be useful. Other than that, the GPU preview is fantastic!
Hey 
It’s a Max thing unfortunately, and Maya does roughly the same. We haven’t found a way to tell the viewport the exact depth of the volumetric effects, as they aren’t real geometries. What Max and Maya see in the viewport is the bounding box of the sim, and the sides of the box that face the camera would overlap everything inside the box and behind it…
Ok that’s understandable. Do you know of a trick to get it draw completely above instead of below? I’ve noticed that when I display smoke in the viewport, it draws above but when I disable smoke it draws below. Could be a glitch or something.
I guess one quick workaround I found is to enable the smoke and set it’s opacity to 0.01 - that way the fire draws on top and the smoke isn’t really visible.
Interesting effect - can you share a screenshot of how this looks?
Yea sure - Here are some screenshots:
If you have smoke in the sim it will draw above geometry and fire draws below. So if you have a sim that is just fire and you need it to draw above for a nicer viewport preview, you can force it to draw above by activating smoke and setting opacity really low (so it still appears to be just fire).
Wow, that’s an unexpected side effect. Gotta investigate to see if we could use it somehow..