What's going on with this shading and how do I fix it ?

GoDomo

Alright I have to do some work and present it in an online 3d viewer (left), I'm not sure what it is but it doesn't seem special but I don't understand why it looks so different in Substance Painter (Right). It looks fine in ue4 and marmoset so I'm not sure why is there artifacts in the renderer. I'm I just beeing stupid and forgeting something.

dlz

it seems something related to the glossiness or specular map as i see. Can you show more about the parameters in each one? Maybe it can be solved with export settings to fit better to unreal engine

Eric Chadwick

Which online renderer? What file format? And which exporter?

dreamylake

The right image does not have any strong fresnell reflections at the outlines or anywhere else, you want similar environment for the left image so less bright sky behind the object.

With the current sky, it looks like artifacts due to lack of path tracing (AO) for the specular reflections.

poopipe

It's not a path tracing issue since painter doesn't path trace and it's not exhibiting the artefacts.
There is something wrong with the way the mesh and texture normals are interacting with the lighting.  This could be down to the assets or it could just be that the renderer / shader are shit.

My first test would be to remove the normal map and see if the artefacting still occurs

Try that and post back here with the results 

GoDomo

Hey, Thanks guys for helping out and sorry that i took a while to comeback.

Ok so Poopipe might be right and as he said "This could be down to the assets or it could just be that the renderer / shader are shit". Seems like the lighting breaks in when the normal is applied. I compared the same normal and asset in Susbstance Painter and Ue4 and they seem to work fine even though the normal is the same.

I should also mention that the model for the online viewer is exported as an FBX and the materials have to be set up in 3d max. I don't know if that could affect it in any way as the same FBX was used for Substance and UE4.

Eric Chadwick

Which online viewer? 

Looks like the viewer does not support the same tangent basis that you baked with. Many tools use Mikktspace, but not all.
http://wiki.polycount.com/wiki/Normal_Map_Technical_Details

Regardless, the colors in the normalmap are quite extreme... areas of bright green and red indicate a large disparity between the angles of the lowpoly and the highpoly. You should try to reduce these, see the Stickies in Technical Talk.

GoDomo

Damn It was on DirectX and not openGL

Eric Chadwick

Yay for quick solutions!

You should still reduce those extremes in the normal map. If you need lower texture resolutions for mobile web, the shading will get much worse as the texture MIPs down.