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I found this (free) nice brick PBR material :

enter image description here

I would like to use it in Blender. I had never heard of PBR before. So when I unpack the zip, I get those files :

  • Brick_Wall.sbsar
  • Brick_Wall_D.tga
  • Brick_Wall_H.tga
  • Brick_Wall_N.tga
  • Brick_Wall_RMA.tga

I've understood that sbar is a property format and is not supported by Blender. So I have to build my own material using those textures.

enter image description here

I've read this tutorial to learn how to setup it.

I added a principled BSDF node and linked it like that :

  • Brick_Wall_D.tga > base color
  • Brick_Wall_H.tga > metallic
  • Brick_Wall_N.tga > (normal map) > normal

Is that correct ?

But then, I miss the roughness map. I read here that

RMA is a type of packed map which contains Roughness + Metallic + Ambient occlusion, which are used with PBR (Physically Based Rendering).

and here that you can extract channels in the node setup by using a "separate RGB" node.

Thus, what should I use and how should it setup that ? Maybe I should use only the RMA file ?

Thanks a lot.

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2 Answers 2

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You don't need the height map for this.. the normal map will work fine (make sure to add the vector Normal Map and make the image texture non-color).

The RMA works like this.. add the RMA image texture and then add a "Separate RGB" node. Each channel in the RMA is an input into your BSDF shader. Most of the time it's this...

  • Red = Ambient Occlusion (you can add this with a multiply on your Base Color if you want)

  • Green = Roughness

  • Blue = Metalic

I know this is an old question but maybe this will help others as this comes up early on Google for RMA and Blender.

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    $\begingroup$ just a quick one, RMA indicates also the order so R(R) => Roughness B(M)=> Metalness , G(A)=> AO. $\endgroup$
    – cnisidis
    Apr 17, 2020 at 16:09
  • $\begingroup$ For the other maps : (D)iffuse (= "base color" or "albedo"), (H)eight (=displace), (N)ormal $\endgroup$
    – thibsert
    May 5, 2020 at 15:11
  • $\begingroup$ I didn't know that about "RMA" as a term. Everything that comes out of Substance is as I descried above.. I'm not sure why. There really should be a standard for that... I guess that's the "RMA" thing. $\endgroup$
    – user170023
    May 6, 2020 at 16:34
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enter image description here

This slide from the Unreal Learning portal is visually clear what's going on with RMA packing.

As far as the order of RGB and its RMA correlation -- this video states it's something each studio / team does differently for their own needs and would be established early on in a project's Master Material.

This link here shows you exactly what the Blender workflow is of this concept

https://blenderartists.org/t/guide-texture-optimisation-channel-packing/1227744

And this slide shows an exact node group within Blender indicating that a single texture is being split by the Separate RGB node into the PBSDF shader's appropriate outputs.

enter image description here

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    $\begingroup$ This tells the OP what RMA files consist of, but it doesn't really provide them with a way to use that knowledge. Consider adding a node group showing using a SeparateRGB node and other necessary nodes to attach the image texture to a (principled) shader. $\endgroup$
    – Marty Fouts
    Aug 31, 2021 at 15:21
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    $\begingroup$ Please add further details to expand on your answer, such as working code or documentation citations. $\endgroup$
    – Community Bot
    Aug 31, 2021 at 15:21

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