ANSWERED: Quixel > UE4 mats

KageMao

Hi all, so I have searched the web for some time now looking for some solid information on using Quixel with UE4 - in particular, which maps go into which material slots~

So, some are obvious ---
AlbedoM = Diffuse
AO = Ambient Occlusion
Normal = Normal
Metalness = Metalness

But what about the others?
Bump
Gloss

Can I use Quixel to make all of the other map slots that UE4 has to offer?

Sands

I posted an environment made in UE4 using quixel in the previews thread. UE4 relies on color, roughness, normal and ao map for most items. Metalness textures you make in DDO do not render well in UE4, because UE4 uses metalness texture as a mask.

For example say you have a painted scratched metal, the scratches are showing on your metalness map in quixel, but UE4 as of now will not be able to render them properly, so inside the engine you will see blown out flat white scratches that look nothing like metal. What you have to do is just give a 100% black value to your metal slot inside UE4 and push the scratches on your roughness map instead. Metalness is only used for separating metals from other objects on your texture, say a gun with a wooden handle for example. High frequency metal detail on metalness maops don't do well in UE4.

As far as glass materials go, there are a lot of different ways of creating glass in UE4, but i got decent results using quixel and just adding an opacity map to my material tab for the glass items.

KageMao

Thanks for the explanation. I didn't realise UE4 had issues with the metalness maps. So what do I do with the gloss and bump maps?

Sands

You don't really need to do anything with bump map or displacement maps in UE4 they have very particular use and are rarely actually used. Your gloss map is actually your roughness map, roughness map is an inverted gloss map. If you set your export options to UE4 it will automatically convert your gloss map to roughness map by inverting it and renaming it for you.

For 99% of assets in unreal you only really need to worry about your albedo, normal map, roughness map and AO. Use UE4 constants for metalness map unless as i mentioned earlier you have a UV layout with some metal parts and some non-metal parts. Don't really bother with spec, the spec value difference between objects in a PBR setting is so little that changing it won't make any difference, if you really need to, use a constant for spec map slot as well.

Wiktor

KageMao and Sands gave good answers to your question, but as for Bump that will be combined with your normal map if you use the exporter, automagically.

DaveW

Sands wrote: »

I posted an environment made in UE4 using quixel in the previews thread. UE4 relies on color, roughness, normal and ao map for most items. Metalness textures you make in DDO do not render well in UE4, because UE4 uses metalness texture as a mask.

I'm not sure what you mean by this - UE4 supports a float value between 0 and 1 for Metalness (see documentation here). It's true that in a 'metalness' PBR workflow you generally only pick values of 0 OR 1, unless you're creating mixed materials, but they do render correctly in UE4 and should look similar to 3DO's preview.


KageMao > If you export to UE4 Optimised, as Wiktor said the Bump gets mixed into your Normal Map and the 'Gloss' map gets inverted into a roughness map. So a typical material will look like this:

KageMao

Ah, so far I have been just flattening the files and saving like that. So export tool is the way to go then? Thanks guys, much appreciated. Will have to fiddle with my workflow a bit it seems then.

Wiktor

Yes, export tool is definitely the way to go. Glad I could help!

Sands

DaveW wrote: »

I'm not sure what you mean by this - UE4 supports a float value between 0 and 1 for Metalness (see documentation here). It's true that in a 'metalness' PBR workflow you generally only pick values of 0 OR 1, unless you're creating mixed materials, but they do render correctly in UE4 and should look similar to 3DO's preview.


KageMao > If you export to UE4 Optimised, as Wiktor said the Bump gets mixed into your Normal Map and the 'Gloss' map gets inverted into a roughness map. So a typical material will look like this:

I haven't had any luck with a scratched painted metal material inside UE4 using metalness map as far as i know it has been a known issue for some time now. You run into issues if you have a solid black metalness with white small (high frequency) scratches, the scratches presented on the metalness map look fine in 3DO and some other PBR based renderers, but UE4 doesn't render them properly.

If you know of a good work around to get that to work in UE4 please share!

DaveW

To be honest I haven't done any texturing in dDo for a while, so maybe I was working around any issues on instinct. What kind of problems do you mean?

IIRC dDo defaults to using black on the albedo for some scratched metal materials, I know that doesn't work well in UE4. Or it could be that UE4 doesn't like interpolating between 0-1 values, in which case, you could up the contrast of the metalness channel (or the mask you are using on the layer in dDo) so you avoid any value between 0 and 1.

agitori

hi, I don't know if it can help you but from my experience if you want a decent render inside UE4 with yours quixel generated maps. You better have to construct your material from scratch ( or using an existing material created by another user ) at least for the time being (until quixel release the export tool XD)

Synaesthesia

It really doesn't take much to hook up texture inputs to a material. I don't see why a plugin is absolutely necessary for most people.