PBR/UE4 questions

CandyStripes05 · Nov 2014

I've spent the past few days reading up on PBR and trying to complete a scene.

My understanding is I'll primary need the following maps:

Base Colour = Albedo aka diffuse minus any lighting details (highlights/shadows)
Metallic = 0 for non-metal, 1 for metal and in between for more advanced situations
Roughness = inverted gloss map, white(gloss) = tighter intense highlights, black(roughness) = wider more blurrier highlights
EmissiveColour= same old thing
Normal = same old thing

So I jumped into dDo and knocked out the basic maps VERY quickly just so I can test the waters of PBR and UE4

this is my current material setup for a quick demo, I didn't like the lack of control using an inverted gloss map, especially when the gloss map was poop so I used my metallic mask and broke it off so I could independently adjust the roughness of the metal and paint. Any ways I'm sure there is much easier ways of going about it then I did but this was only to get a feel for what stuff does.

My questions:
1) The albedo doubles as the spec for metals, is that simply what colour it reflects and by no way meaning the old style spec map is some way integrated into it?

2) How can I use dDo to accurately create maps for PBR and UE4 if it uses spec maps? (not trying to sound lazy and only use dDo, but to get a solid base going etc)

Thanks for any help!, I'm sure I'll have more questions along the way :P

EarthQuake · Nov 2014

For metals, the albedo is essentially the same as a traditional spec map, no difference really, the map controls the color and intensity of the specular reflection. Diffuse is set to 0 for metals as well (metals are very dense, too dense to diffuse light and their color comes almost entirely from reflected light.

For non-metals, reflectivity is fixed at a colorless 4% value, while the diffuse color comes from the albedo map.

Steppenwolf · Nov 2014

Use the UE4 optimized preset from ddo. It saves the metalness, roughness and ao maps in the RGB channels of one texture after export (your gloss from ddo is converted to a roughness map automaticaly). In UE4 open the mask texture after import and make sure Compression Settings is set to TC Masks. In your Material select the Texture Sample node and set Sampler Type to Masks.

When you follow these steps what you see in 3DO should be pretty close to what you get in UE4. You can also put a scalar parameter and a multiply node between the roughness mask to tweak it a bit should you not be completely happy with the roughness result (in 3Do it tends to look a bit more shiny in comparison). Saves you tweaks in photoshop.

CandyStripes05 · Nov 2014

@EQ - thanks for clearly that up

@Steppenwolf - how have I never heard of this UE4 preset! lol thanks for the heads up will have to look into that asap

CandyStripes05 · Nov 2014

Okay did a pretty quick run through with it, had to relearn dDo lol was use to the old version. Here is the shot from 3DO compared to UE4 and my material set-up, please let me know if I should be doing anything different to my material from the maps that dDo pumps out. It is a lot closer then I've ever gotten it so thanks for that : )

Also is there a way to change the focal drop off in UE4? Everything is kind of blurry unless you move the camera right up to it... I'm sure there a check box for it somewhere.

Fwap · Nov 2014

Just double check your greyscale maps have sRGB turned off.

Steppenwolf · Nov 2014

You can tweak the mip map settings inside the UE4 texture editor. On the left side Level Of Detail>Mip Gen Settings. Set it to sharpen 5 or whatever looks good to you. Or if that isn't the problem then it's probably the texture streaming which can be tweaked in the model editor under Static Mesh Settings.

Not sure your masks are hooked up correctly. ddo puts our R=Roughness, G=metallic, B=AO by default i think.

Fwap wrote: »

Just double check your greyscale maps have sRGB turned off.

When you set compression to "TC Masks" then it's turned off automaticaly.

CandyStripes05 · Nov 2014

Steppenwolf wrote: »

Not sure your masks are hooked up correctly. ddo puts our R=Roughness, G=metallic, B=AO by default i think.

Yes that is so much better. You've been a huge help my friend, thank you!

CandyStripes05 · Nov 2014

nearing the end of my project and everything was going good until I decided to change/add some stuff and now I can't get my end results in UE4 to even get close to that of 3DO, and ideas? my materials are all set up the same and everything else looked oaky

I get that the pipes I made might be too small for the detail to be displayed in UE4 (they have more then enough space on a uv map as it was an added assets I basically made a new sheet for them and a few other small things.

3DO:

UE4:

no matter the light placement I do, intensity etc it always come off looking flat and crappy

**more concerned about the wall, if anyone has any ideas? or needs me to post any other info let me know please

Quack! · Nov 2014

CandyStripes05 wrote: »

Roughness = inverted gloss map, white(gloss) = tighter intense highlights, black(roughness) = wider more blurrier highlights
P

You may have just typed this wrong but what you have written here is incorrect.

Roughness:
White = Rough = Broad/Wide Highlights
Black = Glossy = Narrow/Pinpoint Highlights

aphexx · Nov 2014

Steppenwolf wrote: »

In UE4 open the mask texture after import and make sure Compression Settings is set to TC Masks. In your Material select the Texture Sample node and set Sampler Type to Masks.

hi steppenwolf,
perhaps i get it wrong but i believe, when srgb is turned off, it is not possible to put the sampler type to "masks". the sample will deliver an error.
doesn't it have to be "linear" in order to work?

EDIT: sry, my fault. setting sampler to "mask", works like a charm and produces NO error. in fact i just found an error in my own materials. haha. sry again!

PBR/UE4 questions

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