Operating system: Windows-10-10.0.18362 64 Bits
Graphics card: GeForce GTX 1080/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 430.86
Broken: version: 2.80 (sub 74), branch: master, commit date: 2019-07-11 13:50, hash: rB06312c6d2db8
Short description of error
Exporting an object with a material to Collada seems to set the material's roughness to 0, as evident by re-import.
Exact steps for others to reproduce the error
- Apply a material to a mesh object
- Preferrably set roughness to 1.0 in principal BSDF
- Export to Collada, selected objects only
- Reimport Collada file, preferrably in a new workspace.
- Test .blend file: