Cull away objects that are out of camera FOV, but for renders

I used to think that clipping regions (ALT+B) can be used to speed up rendering large scenes by removing unseen objects from the rendering buffer. So you’d set up a clipping region slightly larger than your camera FOV, and you’d cut out, say, a thousand trees that are not seen by your camera.
Turns out, it doesn’t work that way. Clipping regions only work in solid view mode - not in material preview, nor in rendered view mode. They also don’t affect renders. Pity.
Certainly, there are manual methods of excluding certain objects from renders. There are collections, hierarchies, and all that stuff. But if I have a large scene and multiple cameras all over, for multiple renders, each covering only a small part of the scene, it would be very handy to have an automated tool for culling geometries unseen by the active camera. For large scenes, it would tremendously reduce the number of rays traced during render, not affecting the visual result much or at all.
The culling/ cutting could be either precise - roughly cutting a frustum boundary through the entire scene, just like clipping region does, or just hiding away the objects that have their entire bounding boxes out of the camera FOV.
Are there any toys like this for Blender?

You could try something like this, that uses geometry nodes:

Clipping regions vs render regions and last one have to be enabled in Output Properties → Dimension → Render Region

Okidoki, I think you don’t understand me.
I’m not talking about render regions, but clipping regions, which I’d love to have in renders.

This looks promising, yet I’d like to stick to Blender 2.92 for now, because not all the addons I need have yet been ported to 2.93. But I’ll try it out, since I’ll eventually move to 2.93.

Oh i mentioned because you was talking of alt-B (clipping region) and the next would be ctrl-B (render region)… i was too quick … :sweat_smile:

Any way to do it without geometry nodes?

Amazing what you can find in the manual.
https://docs.blender.org/manual/en/latest/render/cycles/render_settings/simplify.html#culling

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Thank you!
I know it was there somewhere. For some reason I couldn’t find it, but I swear, I’ve done my googling first :smiley: