Specular in Unreal vs. Specular in Substance Designer

dread_companion

Unreal supports specular as some kind of legacy thing right? But sometimes it's useful.

But materials in Substance are either spec/gloss or metal/roughness. Is there a way to preview a material in Substance to mimic what the extra specular tweaks in Unreal can do? Or is that pointless and I should just forget about specular in Unreal?

Jerc

If you add a specular channel to a metal/roughness project in Painter or Designer, it will be used by the default shader the same way as Unreal uses it, to modulate the overall strenght of the specular term.

Froyok

Little correction here : you need to differentiate specular and specular level.
The Specular channel in substance is a color map used in the specular/glossiness workflow. If you want the behavior of the specular input of the UE4 shader, you want to use the "Specular Level" instead.

Also the specular input in UE4 is not a legacy parameter, I suggest reading their documentation for more details : https://docs.unrealengine.com/latest/INT/Engine/Rendering/Materials/PhysicallyBased/

dread_companion

@Froyok @Jerc thanks! I will try using spec level instead. Froyok, my intel was wrong. I took the hint off the 2nd reply on this post: http://polycount.com/discussion/132714/what-does-the-specular-channel-in-ue4-actually-do