Non-shiny materials are...difficult!

Larry

Hello guys, i have been trying to make materials in SD. And while some shiny materials like metals,plastic,leather and some wooden floors and bricks are rather easy to recreate realistically, i really struggle with materials like fuzzy leather, velvet, thread wool to make them look realistic. They have microtextures and small fibers which you cannot add to the material (or can you?) to achieve a realistic look. Can someone provide some helpful links for this category? Are these shaders? I also have no idea on how to make shaders as well :P

EDIT: e.g. in this image, i think i nailed the leather handles but these boxes on the right should be some kind of fuzzy leather/velvet style, and the stitches should be like...Thread :P what can i do to improve them?

poopipe

You really need a specific shader to deal with materials like that but you can often get reasonable results but making things blurry

Larry

poopipe said:

You really need a specific shader to deal with materials like that but you can often get reasonable results but making things blurry

Thanks poopipe. Do you have any advice on how to start getting into shaders or some terminology? Does a shader need specific programming or is it done with nodes in programs like SD? Everywhere that I try to find what a shader is, they all talk about the process and not how it is done.

Does for example a graph in substance with PBR outputs count as a shader?

rexo12

A shader is the piece of code that takes the texture inputs and interprets them for the renderer. It makes transformations to how light affects the surface of your geometry - decides reflections and such. They are updated once every frame (I think), so the node graph in UE4 is actually a shader editor, (not full fledged, there are limits on your inputs). Substance Designer is a texture editor that creates inputs for a shader, typically the PBR metal/rough or Spec/Gloss ubershader, which is just the name given to a shader meant to cover all kinds of materials - with some exceptions (glass, skin, etc). 

I don't really think you need a separate shader for cloth, unless it's something complex like silk or velvet. You probably just need a more complex normal map. If you really want to though, you can change the material type in UE4 to the cloth shader, and mess around with the fuzz/SSS map inputs using colour parameters. Read up on the UE4 documentation on it too.

https://answers.unrealengine.com/questions/559535/cloth-shader-model.html
https://docs.unrealengine.com/latest/INT/Engine/Rendering/Materials/MaterialProperties/LightingModels/

Some general advice too, it isn't very obvious what those bags are supposed to be. I suggest looking at some references that are similar to your vision of the material, and do your best to match them. If you can get a hold of an example in real life that makes it much better, as you can examine the roughness too. Add some geometry that makes it clear it's a bag or a package, like a buckle or strap securing it, or a seam where the opening is, like on a backpack. Or both. I'd also make those stitches part of the material itself, and add normal details around them to show the cloth being stretched around the stitching. Making realistic cloth materials is generally all in the normal details anyway.

It might also be worth looking into simulating the cloth and then baking it down into a low-poly.

radiancef0rge

post texture flats

gnoop

PBR shader typically represents a surface defined by micro imperfections  (roughness)   and macro imperfections (normal map) .  But in the real world there is a huge scope of details in between two of those things, smaller than 1 pix of normal map .    It's where you have to fake something.  For the velvet it's special Fresnel effect put in base color .  For some other materials it's extra non-PBR spec level input in the shader to erase shiness completely.  From cracks for example.