The delusional world of PBR

I know This is going to be very controversial, but I have to let it out and want every CG artist doing Texture/Look Dev/Lighting think about.

So this thing called "PBR workflow" is taken over the texture/shading workflow mostly using substance and sutff last few years.

I'm not going to explain what is PBR cuz information is out there, but I'm going to claim that PBR is not something completely new. I feel like people started say PBR after game engines picked up its idea.

ALL the theories and aspects of PBR were there before it took over.

Energe conservation

Roughness / Glossiness / Specular / Metalic

Fresnel

Microsurface

Diffuse / Albedo

Linear Workflow

These concepts were there 10 years ago when we were using Mental ray and Reyes. But not in game engines. It's just bit different terminology and buttons.

So doing "PBR" with Substance painter doesn't mean previous way of work is not "PBR"

It's just different materials need different input values. That's all

If a shader needs metalic map input, it's better to make one. If a shader has spec / gloss input, make one too. You can make identical result in both ways.

I heard one guy saying "Oh because spec / gloss workflow is not PBR" and... that's just not true.

And even if that's not PBR you (think) know, doesn't mean it's wrong or inefficient.

I can make whatever material I want in Spec / Gloss workflow as well as Metalic/Roughness workflow.

It's wrong if you think PBR workflow is the only way to creating realistic materials.

To me, making only one material for one asset (usually have many different materials) is not efficient at all. Why? Everytime you get a feedback which happens all the time in production, you need to export everything again.

It's delusional if you think PBR is actually physically accurate. It's not. Everything in CG, is just approximation of what we see in real world. Raytracing is not physically accurate. Pathtracing is not either. So many shorcuts and assumption are being made when we click render button.

Let me give an example.

Same wood. Different look. one in the left is just simple wooden box. and one in the right is an piece of wooden stick but lights are passing through because it's very thin.

It means when very strong light hit wooden surface, it penetrates very thin layer of surface and than scatters like SSS material. of course there's diffuse, spec reflection too.

But think what you would do when creating wooden box like on the left.

Would you really create that thin SSS layer? or just use standard material?

Just standard material. Right?

But to make it more "physically accurate", you need to make that thin layer of SSS and make it almost invisible than use standard material underneath. I never saw anyone make wood shader like this.

Same principle goes for rubber materials , cloth material, 2sided leaf material.

It's all cheating. but very efficient to achieve a certain look.

We're living in a world where creating dirt layer with simple black and white maps. So why caught up so much how you creating "accurate" maps?

And one another reason PBR doesn't really matter, is our lighting setup, almost 100% of the time our light rigs are not accurate as real world lighting. All those area lights and that HDRI environment you set, will give a decent look, but it's totally guess work and doesn't even close to real world lighting. Don't even need to mention the GI.

Look Development is not about being physically accurate or following the rules. It's about creating what we want to see on the screen. Whatever cheating you need. do it. Don't let this funny little concept of PBR hold your back. You want to put that danm specualr wherever you want!

I worked 2 animation studio and 2 visual effect studios so far and they cheat all the time. They turn off GI (very often), Reflection, Set different diffuse / specualr contribution of certain lights, they even use ambient lights. Physical accuracy? nah man.

My suggestion? Spend more time to train your eyes to have an ability to tell what looks real and what doesn't rather than having false belief some fancy software will do it for you.