uname -r: 4.3.0-1-amd64
Debian 8 testing (sid)
Broken: 2.77a (official tar'ed build from blender.org)
Short description of error
My compositing node system relies extensively on nodegroups, sometimes nested several layers deep. Sometimes, these nodegroups need to process not a bitmap, but simply an individual scalar value - which might be inputted using the RGB node, or the Value node. It's when outputting a scalar from a nodegroup that it breaks; the output value is a bitmap that is one pixel large.
I suspect that any person or studio interested in creating a nested node system for their own ease of use will run into this issue!
Exact steps for others to reproduce the error
- Load compositing scene.
- Create 2 Math nodes. Put each in its own nodegroup.
- Let each nodegroup have one input and one output, passing through the Math node's first input within each group. In both cases set the Math node to Multiply, and the second input to 1.
- Pass in the value 1 for the first nodegroup, and let the output of nodegroup 1 become the input of nodegroup 2.
- Find any image, and plug it into the first input of a color Multiply node. In input 2, plug in the output of nodegroup 2.
- Notice as a single pixel in the image remains unchanged, as the rest of the image becomes black.
I attached screenshots to better illustrate the setup: