CoronaVolumeGrid overlap workaround for animation?

[Jens]

Hi guys

I've never worked with all these fancy schmancy volumegrids, openVDPBFBP clouds etc, but I'm having a lot of fun. However, I notice that when the bounding boxes of the volume grinds overlap I'm getting these "artifacts". I know it's the same when using normal geometry with the volume material added, but then it's much easier to move volume objects around so they don't intersect. Here I can't get the result I want as I can't influence the cloud data other than scale the volumegrids. And to get the look I want I have to have them overlap. Is there a workaround for having multiple clouds in different altitudes so I can fly through them (animation)?

[maru]

Could you send us this specific scene, or a part of it and/or try the newest daily build? There were some fixes to similar issues in it (but still impossible to put a camera inside a volume grid).
The workaround with a camera is to place a "boolean bubble" around the camera. So the camera would be technically outside of the volumetric object (but this isn't always possible).

[Jens]

Done: Uploaded with file assigned prefix: 1616084867

I don't want to try the daily build again during this project as I had big problems rolling back from it (see the daily build discussion for further info). Hope there's a workaround with the current stable build. Else I have to keep trying with IR and move/scale the grids so it's not visible.

I like the idea of a "boolean bubble". But I can't quite figure out how to do this with the corona distance map. Something with linking a large sphere to the the camera and then... I probably need to go through your render time boolean thread again haha

[TomG]

Personally I wouldn't use the Distance map for the bubble, it isn't really needed and adds extra calculations. Instead, use Max's Realtime Booleans. Should be fine so long as you are using cubes with a sphere to be cut out from them (more complex geo runs into issues, as with any booleans).

EDIT - also I am not sure the Distance map would then count as being "outside the geometry" as it is really just an effect of opacity on the object, not actually changing the geo, so Realtime Booleans may be a must in fact. It's how I have done it in the past.