Author Topic: Cameras inside fog volumes don't work as expected  (Read 1514 times)

2017-05-30, 15:42:28

somedoggy

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I was testing light shafts with volumetrics and when unable to get anything working I searched online. Although I found a workaround, this seems to be a pretty strange issue, and for any scenario other than a static camera this technique does not work at all.

At first I was using a global volume, but switched to a box to allow more light to get in initially. This didn't work, and the workaround I found is to move the volumetrics box just outside the camera. For some reason this works perfectly, and I'm guessing booleaning a tiny sphere out right at the camera would work too.

Camera is inside fog volume:


Volume mesh is edited so camera is just outside, but the rest of the volume is kept as identical as possible.


An observer should not need to be in a different participating media (or here vacuum) to see light shafts inside the media.

2017-05-30, 19:19:02
Reply #1

PROH

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Hi. This is a well known issue, caused by the fact that Corona volume material used on an object isn't a 3D volume but a "surface" material.

The "workarounds" you're mentioning are ATM the way to go.

2017-05-30, 20:26:43
Reply #2

somedoggy

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Yikes. I guess for the most accurate results you can always bool a small sphere at the camera source, but that's not the most flexible workflow.

This information makes sense of similar problems I've had with participating media in Corona when playing with planet renderings, and a few other points of volumetric weirdness I've encountered.