Best method for combining materials with PBR?

Development Rendering
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So, over the past month, I’ve spent a significant amount of time, trying to study how to use PBR in Blender and how to create PBR materials also inside of Unreal.

However, I’m not sure how well blender is able to translate PBR materials over to Unreal. I assume I would need to re-create the materials inside of Unreal?

I’ve been actually trying to develop a number of procedural textures and a number of metal and dielectric PBR shaders for various materials to create my various textures. The idea is to then combine everything and bake all the materials into single textures and then import the model and the textures into unreal and set up a material to handle everything in Unreal. Then I could create an RGB mask to control what parts to determine which parts are metal and which parts are dielectric.

Another thing I’m wondering is if it is possible to add more than one rgb mask? For example; I have a single image that has some parts wood, some parts metal, and some parts fabric. The fabric and wood are two different dielectrics with different values. The metal will of course need to be metal. So… I map the fabric to R, Wood to G, and metal to B of the RGB mask. Well… fabric needs stains, wood needs smudges, metal needs smudges and maybe rust… heck maybe we even want to throw a layer of dust on our model. The problem is that smudges, dust, ecs are going to be a another dielectric material… maybe one for each depending on how rough or reflective we need each to be.

The question is… how much of this information would be handled within your different texture maps? How easy is it to set up different masks to handle all this?

Or am I overthinking this entirely?

Is there any particular reason that doing all of this work in Unreal would benefit me more than doing everything in Blender first and then finishing up in Unreal?

Another question that I would like to know the answer to, in the live training, one of the devs converted a normal map baked inside of Unreal using Photoshop into an 8 bit HDR normal map. I’m stuck using CS2 for my project, which is pre-HDR. Is there another inexpensive program that can convert this correctly?

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Not sure about Blender but the Indie Pack of Substance Designer, Substance Painter and B2M is available to buy with 34% off so you can get all 3 for $199 instead of $299. You’ll have to be quick to get it though because the sale ends on 29th.

It will make creating PBR textures A LOT quicker and easier. I’m getting mine on Friday after messing around with the demo for a few days following tutorials on YouTube. Worth every penny at the full price but for $100 cheaper it’s a steal!

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There are a bunch of methods to combine materials. One is to have one materials with masks for what material it is (like you said), you could have more masks if you need more stuff going on in that material. If those extra masks are just grayscale textures they are easier to set up (and swap out) but require more memory (and texture samplers), if they are RGB textures they are a bit harder to set up and swap out since you’re using them for several materials, but they are more performant.

You could also look into layered materials, they are a bit expensive but are really nice when you want to blend a bunch of materials. In your case you could make a wood material, a metal material and a fabric material separately, then blend them all using grayscale masks. Pretty useful but they can also get expensive pretty quickly if you use tons of layers. Layered Materials | Unreal Engine Documentation