compositing result as uv-texture

Hello beloved blender paramedics!
after one year diggin into blender, i am now that far to start my first question here in this aiding forum.
right now i am into greenscreen keying of persons (stills only) and want to map the result as uv-texture on a 3D plane.
but i cant find any way to use the final compositing node as image texture in the material setup.

my currently solution is to exchange the ready-key with the used texture after the render node with the “mapUV”.
i dont like this way because there are 3d-object overlaps which are disturbing after adding the keyed output.

i also dont want to save the keying result as extra file. everything should be in-line for fast changes.

so… is there a way to use a final comp as texture?

No. The scene gets rendered and compositing comes after that, it’s a post-processing step. Save it in a file. You could use file output node to automatically save the compositing result, just pay attention that you don’t use it in a scene with the same compositing setup. It either wouldn’t render the scene or if it has render layer node, overwrite the file.

it’s a post-processing step

mhm - i see …