Cubemaps not blurring with Roughness

[PixelSonic101]

When generating a cubemap, it doesn't blur with the roughness.is there a way to fix this?

[thexa4]

You have to start the game with the -forceallmips startup parameter for rough materials to look good. Can you try running with that parameter?

[vaqxai]

What's the reason we need this parametr? It kilka hacky

[thexa4]

Roughness is implemented by sampling from the lower mip levels so those need to be in memory. By default the engine only loads the highest level so then your rough metal things look smooth.