Cycles Pointlessly Rendering Blank Empty Space

Is there a way to prevent cycles from rendering useless empty space? I have a single object over a transparent background. I’m doing a panoramic shot in 4K. Cycles spends minutes and minutes rendering absolutely nothing. Just as a test, I even had cycles render a completely empty scene - it took forever. I’m trying to send the scene to a renderfarm. They quoted $1000. The idea of paying $1000 for all this empty scenery is just insane. Is there any way to prevent cycles from rendering useless empty space?


Is it just blank, or is there a volume or something there that mmay not be physically visible to the eye but cycles still has to check

Blank - nada

Can you border render?

No - because it’s animated. The object moves around the frame and at times right in front of the camera.

You still should be able to trim off some of the top and bottom if it never passes below / above camera… remember, border render in preview rendered mode, not solid / material modes.

apart from that… how will blender know where the object is? it needs to render that space to confirm its not in those areas. Plus… blank areas render pretty fast in general.

Branched path integrator is significantly faster than the regular path tracing integrator on empty space in most cases. Just make sure it’s set up properly (minimum # of AA samples, do the rest with the subsamples and lamp samples)

It does pass above and below the camera. Because I’m using 200 samples in 4K, it takes cycles 4 minutes to render a completely blank frame. But I have 4000 frames to render.

I don’t know how cycles will know where the object is. All I know is we put a man on the moon, we reduced massive computers to the size of a cell phone, and we’re on the verge of printing human organs. Human ingenuity can accomplish extraordinary things. Rendering blank space is well within the realm of human capabilities. I know someone out there has the ingenuity to accomplish this. I’m just hoping that person finds this thread.

Thank you - the branch path integrator really speeds things up!

There is already a solution for that - Adaptive sampling. The blank tiles would be stopped almost instantly in this case. This was attempted in Cycles but AFAIK not kept due to some problems.

thank you zeealpal and burnin - i will check it out!