Is it possible to specify a complex rendering area in Blender? I am trying to render a complex object (suppose this is a torus). The area occupied by the object itself is much smaller than the area of the object bounding rectangle. I only need to render this object.

The surrounding scene is not important to me (besides its effect on the object lighting). I try to adjust the object material and I often have to rerender the scene.

It takes a lot of time, so I want to throw out the rendering of all the excess. I know about rendering boundaries, but this only works for a rectangular area, which is not effective for a torus. Can I somehow define the rendering area including only interesting object?

My guess how I could do it:


Disable some tiles during rendering.
Determine the non-standard ray density distribution for tracing.


Unfortunately, I did not find the standard functions and plugins for this. Maybe someone has already solved a similar problem and knows the solution.
You could put your model on a renderlayer and then model a plane with a custom shape hole on another layer and then tick exclude and mask for that layer on the model-layer.