I'm trying to composite a set of rendered frames on top of a photo of the beach. This works if I'm rendering the whole 3D scene, but I was trying to use the strip of pre-rendered images, in OpenEXR format, each with their own alpha channel. (I completed the Blender Guru beginners tutorial)
Following this tip on Reddit https://www.reddit.com/r/blenderhelp/comments/rl1g1m/how_to_change_compositing_after_rendering_image/
This is what I have come up with:
Using the Image Sequence instead of the Render Layers at the start, an image source, the 'Alpha Over node' and the compose node for output. You can see in the screenshot that the output preview looks perfect. However, when I click F12 to render a single frame, I can only see the doughnut with the checkered background.
I select the Composite node, then click 'reset node' in the node properties panel and the preview panel looks correct again, as far as I know, I didn't change any of the composite settings to reset, this feels like a bug.
Turning Compositing on or off in 'Output -> Post Processing' makes no difference, although turning off 'Sequencer' gives me a completly black 300 frames.