Re-render part of your render

Is there a way to user the ‘Render Region’ option, but have it overlayed on your previous render?
So when you change a part of your scene you can re-render only that part but still see the complete image.

I wish. But no, not that I know of.

1 Like

I think it is possible with use of render layers and merging them together in the compositor, but at that stage you might as well use the easier method: doing it all externally in an image editor.


Ok, thanks for the info!

Maybe I’ll try to make an add-on to do this.
I know how to program, but have never made a blender add-on.

1 Like

The compositor is definitely the simpler and better way to go.
Don’t forget that if you have an alpha channel, you should only use the original one. Otherwise the region you lay on top will add opacity to the semi-transparent pixels.

1 Like

Thanks for the tip!
I tried it in the compositor and it works, but it’s kind of a hassle to always have to save the image and reopen the compositor.

maybe this helps: Add-on : Camera Regions

1 Like

I made a compositing setup for this purpose.

  1. F12 to render the full frame and alt+s to save the image.
  2. Open the saved render in the image node.
  3. Select a region to update with render region ctrl+B.
  4. Now on rendering the only selected region will render and be overlayed.
  5. Disable by unchecking Output Properties > Render Region.

You can download the file here: