Operating system: Windows-8.1-6.3.9600 64 Bits
Graphics card: GeForce GT 635M/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 391.35
Broken: version: 2.81 (sub 16), branch: master, commit date: 2019-11-20 14:27, hash: rB26bd5ebd42e3
Bug or unintended behavior:
Baking using "Selected to Active" does not take into account transparency
How to reproduce:
Create two objects with materials and textures assigned to each;
One texture to be baked to One texture with an alpha channel (optionally a normal map)
In the shader editor, modify the material of the object with a transparency channel
Join the transparent textures' alpha into the alpha of the shader that is being used (optionally join the color of a normal map)
In render properties, enable Selected to Active and use an appropriate ray distance
When baking combined or most channels, the transparent areas will assume the color as if it were completely opaque,
When baking normals with transparency, the transparent areas will mix with the normal of the geometry that is being baked to the active selection.
Both outcomes are unfavorable when working with transparent cards/ribbons.