The lamps in this scene are stationary. Only the lit object is moving.
However, in this render, it seems like the lighting is being baked onto the object for several frames (perhaps 8 or 10) at a time, instead of being smoothly updated on every frame. Is that a bug?
If not, what could I be doing wrong?
I am new to this forum and cannot yet post links, but here is the YouTube ID of the rendered video:
The blend file is apparently too large to upload but you can see that the object consists of many smaller icospheres.
Looks like the shape of geometry is behind it. Light is not sticking anywhere, just at one point some faces move into position where light does not hit them anymore and they turn dark. There are a lot of small faces that are oriented towards the light. When they get occluded by other parts of geometry, they lose brightness very fast.
Thanks for your reply. There’s no underlying geometry (such as one large icosphere, for example). The thousands of tiny, visible icospheres are the only geometry in the file.
I think kesonmis was referring to the geometry of the thousands of tiny icospheres. What you’re seeing is (almost certainly) correct. As the mass rotates, groups of icospheres come into and out of alignment so their faces are reflecting light back to the camera. So a sphere made of tiny facets like yours will have a very different light falloff than a smooth sphere, and might look unintuitive or wrong. This is actually how most commercial retroreflectorswork.
Back in 2016, I was in a rush so I must have scanned kesonmis’ answer too quickly and took ‘behind it’ literally. My apologies. Now (five years later), I have read it properly. Thank you.
My apologies. Now (five years later), I have read it properly. Thank you.