Unreal caches files for the editor in the DDC cache. For the game, PSO is precaching.
Usually you don’t have to precompile all the materials for the editor, Epic recently made shader caching on demand. So that you don’t have to calculate all the permutations at once. In theory, it could help you. But I didn’t try it.
[ODSC - On-Demand Shader Compilation]
(https://portal.productboard.com/epicgames/1-unreal-engine-public-roadmap/c/847-odsc-on-demand-shader-compilation)
Btw: sometimes unreal starts to predict permutations of some parent material after opening a level. It’s because you don’t set material usage foer example for spline mesh, and after opening the level it will change for you so you don’t have artifacts. But then it start recompute permutations again, because you change master material. Same for example if you using Nanite and you dont have check usage in material for Nanite.
Check output log, in filters on top of the window uncheck messages and check warnings, if its there something about it. Or turn it off in the material if it is used incorrectly - for example, you don’t want to use Nanite on meshes with translucent material. It will warn you in editor.
But if you have tens of thousands of shaders computations after editing the master material, you can try to reduce them. Certain features in the engine (eg. support for stationary and static light) or static switches in the material will create more and more permutations for you, because it needs to cache all possibilities that you using.
Understanding Shader Permutations
Optimize Shader Compilation & Package Sizes
In summary:
- You can try turned off ODSC
- check material usage - should be yellow warnings in output log window (for me it looks like it will be this case)
- reduce shader permutations