Operating system: Windows-10-10.0.17763 64 Bits
Graphics card: GeForce GTX 1080 Ti/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 430.64
Broken: version: 2.80 (sub 74), branch: master, commit date: 2019-07-08 23:33, hash: rBac8c795429f9
Short description of error
Any update of material parameters in material properties editor causes short input blocking UI freeze roughly 2 seconds after parameter change. This is very annoying when user changes a material value, proceeds to interact with viewport which hitches a moment later. There is no logical reason 16px wide material thumbnail generation should cause entire UI and input to freeze. Especially with powerful hardware, such as GTX1080Ti.
Exact steps for others to reproduce the error
- In a new .blend file, open material tab of properties panel and create a new material
- Change any material property which has impact on material appearance and quickly proceed to orbit the viewport.
- Notice the viewport hitches and freezes for a short moment roughly 2 seconds after every material update
Result: Viewport and UI freezes for a short moment roughly 2 seconds after any material update.
Expected: No freezes ever occur during viewport navigation even if material properties are edited.
Proposed solution: Do not delay material thumbnail updates, but update material parameters only on mouse button up/num input enter. Not during the interaction with the UI elements but right after mouse button is released / numerical value is confirmed with enter key.