RayTraced Reflections problem

KirilZangagolev

Hey guys, I have a weird problem with ray traced reflections. On the first image its just a lowpoly cube with metalic and 0 roughness in the engine. The next images I made a few mirror objects with highpoly baked normal and standard unique textures from painter. The baked objects look really weird with ray traced reflections. How do I fix this?

Obscura

Don't use a normal map on the glass parts? Its unnecessary anyways. Its a completely flat surface. A roughness map is more useful.

It looks like you have 2 different issues occuring with those normal maps.
Image2: Wrong tangent space
Image3: low precision normal map.

KirilZangagolev

Yeah thank you when I remove the normal the noisiness goes away but how do I change the tangent space so there isn't that distortion? 

Obscura

Substance should bake for mikk tangent space by default. Thats what Unreal engine uses.

KirilZangagolev

But I  dont have a normal on the mirror polygon anymore

Obscura

And its still warping?

KirilZangagolev

ye

Obscura

Look at the world normal pass, and see if it shows flat there.

rollin

Could it be the mesh normals of that mirror / frame aren't pointing straight forward?

KirilZangagolev

world normal isnt flat

KirilZangagolev

OMG such a dumb problem. I had the mirror objects as one smoothing group before export for unreal. When the mirror polygon is its own smoothing group the world normal is flat and the reflection is correct.

Obscura

Thats why we were suggesting looking at the world normal pass.