I'm late to the PBR party! Some questions...

[Streetwise]

I'm hearing more and more about PBR workflows and (up until now) always thought that my workflow tried hard to match physically based materials. But with what I'm reading about PBR, it sounds to me like it's even different than what I thought I was already trying to do? So here are a few questions to help me clarify what exactly makes it different/better than what I'm doing now.

- Current workflow is VRayNext. I use a mix of shaders from Siger, Poliigon, and standard v-ray materials (diffuse, glossiness, bump, dirt). How is PBR different?
- A client of mine is on VRay 3.6 and only uses basic vray shaders, limited to diffuse, glossiness, bump, dirt). How/Why would I describe to them to use a PBR workflow? Is it possible with 3.6?
- I've just started looking at Substance Painter as a way to add realism to some of the materials that I use. Is this a good way to go? What is the difference between it and Substance Designer?

I'm always interested in taking realism up a notch, so any help with understanding the PBR workflow or its definition would be greatly appreciated!

Thank You.

[Ihno]

- Current workflow is VRayNext. I use a mix of shaders from Siger, Poliigon, and standard v-ray materials (diffuse, glossiness, bump, dirt). How is PBR different?

PBR uses 3 maps basically: Diffuse(albedo) Glossiness(roughness) And Metalness. PBR isn't more or less realistic than the old approach. It's just a standard.
For it to work you must have glossy Fresnel checked and a pure white reflection amount. Depending on how you export from Painter(or something else) you also need to decide between "use roughness" and "use glossiness".

- A client of mine is on VRay 3.6 and only uses basic vray shaders, limited to diffuse, glossiness, bump, dirt). How/Why would I describe to them to use a PBR workflow? Is it possible with 3.6?

Partially: with rough fresnel (which is in 3.6 I think) the only ingredient of PBR which is missing is the metalness.
One could use a blend material with a metal shader in the coat 1 and the metalness as the blend texture for it.
The metal shader itself would need to take the color from the diffuse. I'd use the complex fresnel map form siger take the silver preset (which is very bright) and multiply it with the diffuse. This should work

- I've just started looking at Substance Painter as a way to add realism to some of the materials that I use. Is this a good way to go? What is the difference between it and Substance Designer?

Yes it's definitely a good way to go! It's the most intuitive and hassle fee texturing tool.
Substance Painter is layer based like Photoshop, Designer is node based like Nuke. Designer is more for creating procedural materials.
And Painter is more about taking those materials and paint them onto the asset. You don't need designer to use painter for anything though.
If you want to learn painter I highly recommend buying this curse: https://flippednormals.com/downloads...tance-painter/

[PIXELBOX_SRO]

Little question Ihno:
Apart from more correct metals, do you find it generally better to use metalness over specular workflow? Do you generally find the shaders better looking? If you were to give it some sort of percentage, how much do you think it jas improved the quality of the tendered image? Of course, compatibility of this workflow with Unreal is undeniable, i am jist trying to find reason for hopping on the bandwagon....

[piotrus3333]

metalness has nothing to do do with PBR. it is just smarter and more efficient way of saving textures: rgb specular of metals goes into diffuse and specular stays grayscale. you are adding just grayscale metalness mask. big saving for realtime engine. also more straightforward for painting diffuse maps as specular rgb for metals is basically the colour you see - like colour of gold or steel.

PBR shader is just a shader with values based on real world measurements. Next is not needed for that.

[Ihno]

A pbr shader is a good starting point. When you have glossiness, diffuse and bump in place it's always easy to take the glossiness into an output node and drive the gtr falloff with that or something else.
Substance Painter is also able to create user defined outputs. So you can get additional masks for all sorts of things. I love metalness because it's now easy to create photoreal metals which are also gpu ready.
No unrealistic 15+ior setup or no complex Fresnel map that doesn't work on gpu. It's easier and faster to setup too.

PBR shader is just a shader with values based on real world measurements. Next is not needed for that.

In a perfect world... But that's not how that term is used. The Internet is full of pbr shaders with totally wrong albedo and so on.
Its Physically Based Shading not Physically Perfect Shading

[piotrus3333]

this is Chaos Group forum not “the internet”. lets be professional here.

[piotrus3333]

this is good place to start learning about concept of pbr:
https://www.fxguide.com/featured/gam...-me-rendering/

[Ihno]

I was trying to make the point that PBR is just a standard. And no guarantee to create physically accurate materials.
It's just a term for driving materials with those 3 maps. One can do all sorts of things with those maps.
It's not about real world measurements at all. Except the underlying math, but that's also the case for any material in vray or any other render engine that's photoreal regardless of whether its PBR' or not

[PIXELBOX_SRO]

Thnaks for the links and explanation guys, will have a read

[PIXELBOX_SRO]

i remember Vlado saying that using Specular gives you a little better control over the look of the material...no chance to find the thread though :-/

[piotrus3333]

the idea is not to have better control but to have limited control. to stay within boundaries of physics. its a shortcut to realism of shaders.

[Streetwise]

I was trying to make the point that PBR is just a standard. And no guarantee to create physically accurate materials.
It's just a term for driving materials with those 3 maps. One can do all sorts of things with those maps.
It's not about real world measurements at all. Except the underlying math, but that's also the case for any material in vray or any other render engine that's photoreal regardless of whether its PBR' or not

Thanks for the great information! In a non-gaming environment, what might be some advantages in adopting this workflow? To me, it looks like just a different way to do the same thing?

[Ihno]

Thanks for the great information! In a non-gaming environment, what might be some advantages in adopting this workflow? To me, it looks like just a different way to do the same thing?

Actually vray, by default is set to PBR (glossy fresnel checked).
The advantage is that its compatible with substance and other PBR tools. You can use the maps right away, without the need for doing stuff in Max. Also, the appearance in substance is very close to the actual render output. As I mentioned earlier, it's then up to you to edit those maps for other inputs of the material if you want.