[Bf-committers] render percentage and compositor behavior?

[David Jeske]

I wanted a quicker render+composite for proofing, so I set
render-percentage to 50% expecting it to work, and poof, my composite
started doing very weird things and crashing. I'm sure there are some bugs
here, but I'm not sure what the intended behavior is, so I'm not sure what
test-case to reproduce and what bug to file.

See attached blend for some examples. Try connecting nodes up and compare
the preview to the rendered output. Try changing the render percentage and
re-rendering.

Can someone familiar with the intent here answer some questions?

a) What is render-percentage supposed to do in the compositor? ..to
image/movie input nodes? ..scale/translate nodes? --- Seems like sane
options are to affect all inputs and scale/translate, or not affect
composite at all (aka only affect that scene's render layer's output).
Neither of these is happening right now.

b) Where are Mix and Alpha-Over nodes supposed to get their output size
from? Currently they seem to get preview size from their first input, but
their render size from the scene?. This leads to inconsistent
preview-and-render. I don't know how render-size from the scene can be
valid, since you can bring in render layers from multiple scenes with
different sizes.

c) I don't see any way to tell what size image is appearing at a
node-output. It would be nice to have some info in viewer, or perhaps an
"Viewer Info" Property panel when a viewer is the active object.

Thoughts?