Expanding Beyond Basic PBR Materials

ReneFisher

Greetings polycount! 
While I feel like I have a decent understanding of the artistry behind building realistic materials, I feel like my technical know how is lacking a bit.

I realize not all materials need to be super complex in order to create convincing results, but I'm having a hard time finding resources and tutorials for using the material editor. Now there is documentation for each function, and tutorials on how to create vertex painted mats, but I'm talking more about knowing what to use, when, and knowing what everything does and is used for in the material editor.

I realize this is super vague, but I guess I'm just open to any tutorials or videos that really explain what's going on in a material rather than just "copy what I did".

If you believe you can offer me some help, let me know because it would be greatly appreciated.

Larry

Hello, i am just starting getting into material creation but one thing i can tell you for sure, is that there is no way on teaching you how to create your own. That comes from experience. And by that, i mean look at, and recreate as many materials as you can from videos and tutorials, and try to see the way of thinking, and how people approach different types of materials. Also, experimenting alot by yourself will give you alot more experience because you WILL accidentally learn something totally different from what you want to make. Try and join the material challenges here on the forum, and look at other people's way on how they tackle the challenges. A good problem solving skill is required in this field for these purposes, and in 3d in general.

I would recommend getting into all of these if you want to specialize in this subject, otherwise a decent general knowledge on basic material creation like wood metal copper gold etc, would be enough i guess.

Butthair

It might be worth looking into the differences between legacy and pbr shader math. By legacy I, of course, mean lambert/blinn models.
I make shaders quite often, for effects and simple things. The approach I use for building up any material is from a simple set of nodes - the core shading, then expand from there. At that point, its a matter of trying a method and seeing if it's the result I like.

A simple shader setup is the normal set of textures - Diffuse, Normal, Rough, Emissive, Metallic. Making and testing this part is key, everything gets built on this. From this point on, it's about getting to a specific look that can't be achieved with just a simple setup - it needs to be expanded.

At a certain point, working on a shader becomes creating certain masks and blending them accordingly. For that part of the workflow, I'll turn on realtime nodes and realtime editor preview. I use preview node, especially when working on a masking expression. Also, previewing the right node is important - sometimes I need to preview a specific area for debugging, but usually the preview node is that final node in the sequence for that expression (for example, building a fresnel mask between two colors, the final node would be a lerp - that's my preview node). And it usually is a lerp, or else it's a multiple or add.

At a general glance, materials are very similar, it's only when it comes down to specific styles or animated effects that things get messy and complicated. For example, I made a crystal and shader - it was 3 meshes, the inner crystal, crystal volume and crystal surface. The inner crystal and crystal volume used the same shader with adjusted values, the crystal surface was using a different shader that didn't need refraction and had a fresnel mask for opacity. The only way I achieved the final look was through studying the material I was trying to recreate and seeing which aspects of the material were still missing. The crystal surface was missing for a long time as I had no way of achieving the look with my current shader.

If you haven't already absorbed Eat3d and 3dMotives free tutorials for UDK shaders, do so. They are in UDK, but the principles are near 1:1.

When it comes to knowing which nodes to use or how to achieve a certain effect is not a science. You try one method, then another. Which one looks better in engine? Always check how it looks in engine. Lot of shader compiles, I know.

A lot of nodes in the material editor are for specific uses, sometimes post process only. At the end of the day, it's vector math. You can manipulate rgb vectors and/or world space vectors (there's other specifics too..) How you do so is in your creative problem solving. To be better at problem solving these things you play around more with the math.