Best way to use "traditional" textures? (eg Arroway)

What would be the best way to use traditional textures from a site like Arroway in UE4?

I have a diffuse, a spec/gloss, and a bump map. I was thinking of taking it through Substance Designer but thought I’d check to see if there was a better way to do it.


I’ve tried taking them into Substance Designer 5 and Bitmap2Material 3 but nothing looks quite as good as they should. Should I stick to using these types of materials with Corona and VRay, and keep my UE4 procedural?

You mean your issue is with converting spec/gloss to metal/rough?

Yeah I suppose so, the diffuse works as intended hah. I’m just unsure how to convert a spec/gloss map and bump map for use with UE4, or if it is even worth the trouble.

There’s a “ConvertFromDiffSpec” material function in engine content that allows you to do this. This converts classic Diffuse + Specular textures to BaseColor, Metallic and Specular. In your example the gloss map should be inverted (for example with a OneMinus node) and would go into roughness.

This adds a handful of instructions, but the impact is quite minor so it might be worth it to save you some work. Converting a bump to a normal map can technically also be done inside your material, but this is quite expensive, even at a low quality, so I would recommend converting those outside of unreal.

You can also download the Elemental Demo and rip a fairly decent master material out that allows you to use spec/gloss :cool:

Thanks a lot Arnage and Chesire! That’s exactly what I needed. I must’ve been using the wrong phrases to search in Google because I couldn’t find anything.

I started learning about the world of 3D with PBR and I’m having trouble working with the spec/gloss workflow. I’m trying to determine if a texture pack from a company like Arroway would be a good solution for my materials. Can’t wait to try these solutions out!

One more quick question for Arnage, how do you know to invert the gloss map and stick it into roughness? Is this just common knowledge that comes with experience? Or is there some documentation?

I’ve been trying to learn the Substance suite, UE4, Vray, and Corona and I’m never sure about little things like this.

@James_Gallagher This is a very good read:

High gloss = sharp specular reflection
Low roughness = sharp specular reflection

There’s no one to one mapping, you just have to guestimate the min and max values for the roughness and then convert the specular to that range.

It comes from understanding what each map does. Gloss defines the shape of the specular highlight, where black is a very wide diffused highlight and white is a sharp point. This is the inverse effect of a roughness map as there black is shiny like a mirror and white is diffused.

Keep in mind though that this conversion is not 100% accurate as roughness in a PBR workflow also automatically scales the intensity of the specular highlight to preserve energy to stay “physically correct”, something that is not part of a classic spec/gloss workflow.

Thanks for all the information! I Look forward to reading that document from Marmoset, I should probably re-read Allegorithmics PBR guide as well. I appreciate the help!