I stumbled on some unexpected behaviour:
Having a MeshStandardMaterial with Roughness 0, Metalness 1
seems to not use the best available Envmap and this makes reflections more blurry then they should be.
Googling leads to lots of former problems with the PMREM or its internal resolution.
However looking at the created texture and its use for scene.background shows the expected details.
So this is not the problem here.
White Car where the difference is clearly visible, left reflection, right background.
Expectation:
Metalness 1, Roughness 0 should look like a “perfect” mirror (depending on the envmap resolution),
as can be seen in Substance Designer and Blender as well.
Current state:
Metalness 1, Roughness 0 is far more blurry then the background or the highest PMREM Level
To me it looks like it accesses the wrong level of the PMREM result ?
Resources:
Standalone demo based on hdr example,
however the PMREM rendertarget is attachet to the window object in threejs
and then added to a big cube in my demo.
Live version
Deployed files as zip:
https://tmp.intelligentgraphics.biz/gARAx/threejs181_blurrymetal.zip
I made a fiddle (unfortunately without seeing the PMREM)