PBR shader's

I’m a little bit confused. The trend PBR is changing the standard vision on cycles but I don’t get it 100 %

I know what PBR means and how to use it very basically. Just use the maps and search for the IOR value.
But before the trend, I knew how to use overlays or combine metal en rust for example.
But with the new PBR shaders, i don’t know if that is wrong

What is a good PBR shader? And Can you give me some tips to make some more “advanced” Materials?
Because I feel like I’m stuck with only using the maps and all

Don’t get me wrong. I love the new shader and I’m really happy with the results it gives.
But maybe there are some pros that can give some nice tips and tricks to use this shader

  1. It’s a fixed workflow allowing you to produce 90% of your materials with the least amount of memory used for textures, extremely suitable for gaming engines. Albedo (base/metallic) color, metallicness, roughness, transparency/presence, emission, and AO is pretty much all you need in terms of maps (which in game engines can be combined for minimum required bit usage but we don’t typically worry about that here).
  2. IOR is what they want to get rid of (for fresnel control), but rather provide control over facing (f-0) reflection instead which is much more intuitive.
  3. They should be built to maintain energy conservation as long as everything is within limits without user having to input or calculate anything. The fresnel function should account for better than the builtin fresnel function.
  4. Download new textures built for PBR use matching typical cheat sheet values. Albedo maps differ from diffuse maps in that they are completely stripped for lighting information (shadows and highlights), usually involving polarizer filters and some photoshop wizardry, and typically look more uniform and duller. Use cheat sheets to obtain other valid value ranges, and make sure the PBR shader either comes with translation rules or have the same roughness mapping (the builtin roughness has uncontrollable range).
  5. To get proper diffuse, you may have to do your own stuff outside the shader (i.e. modulate albedo and F-0 specular with AO map), depends on the shader (I only use my own, never looked at how others do it).
  6. The best PBR? At this stage I believe the upcoming disney shader under development will be able to handle most cases. It has some extra very useful controls; new sheen shader not in vanilla, F-0 tint control for dielectrics, builtin topcoat with separate normals, different Oren Nayar response than vanilla, ability to turn off specular completely should you need it, SSS component, auto handling of thin/singlesided specular, anisotropic specular (also for dielectrics - this is not a metal only phenomena), and some basic refraction. It still has a long way to go to get to the real disney version, but I hope those things can come later without completely breaking anything for backward compatibility.

What is wrong with “using the maps and all” (especially if you’re pleased with the results)? That’s the whole point (see point 1); if you have good maps the material is complete - done - very little messing around om the node editor required - spend the time rendering instead :slight_smile: Most engines have their own additional controls, where the engine is tweaked to utilize these the best way possible (quality and speed). So it’s hard to come up with a “proper PBR shader” that does everything, and does it efficiently without additional overhead. Go too crazy, and you loose the advantage it was supposed to have (simple and with minimal amount of controls while getting the job done). Which is why some of us prefer to do it ourselves. I’ve made my own version of Disney (long time ago, and lacking/replacing significant shading elements that cannot be done), which also allowed wetting utilizing some passthrough info. Those passthrough connectors made it extremely versatile.

Most of what is posted about PBR is actually about particular implementations and therefore an incorrect answer to the question ‘what is PBR.’

The basic concept behind PBR is to create shaders that react consistantly in different lighting conditions. Shaders have traditionally had to be reworked every time lighting conditions changed and that causes a lot of extra work. Coming up with standardized lighting conditions and shaders that work consistently as they would in the ‘physically based’ world means that once a shader is written it shouldn’t have to be reworked. THIS IS THE WHOLE POINT BEHIND PBR. It is also why it’s not ‘just about game engines.’ Game engines move assets between various lighting conditions and so reworking shaders constantly has a major cost. That, is why game engines are pushing PBR. So is animation and any video for the same reasons.

It is very frustrating to hear constantly people who don’t get this putting misinformation about why "PBR isn’t necessary as (insert person’s favorite render engine) already did this. They did not. It has to do with a consistent repeatable workflow. If one is rendering still images and not moving assets around, it of course seems superfluous. It’s not.

Just a quick add-on to the previous post. PBR is ‘not’ about making things look more real. That is the mistake people are making that lead them to think many incorrect follow up thoughts about PBR. It is about consistent results, period. Please help others understand this so we can get past misleading statements that keep cropping up.

I completely agree in pretty much everything, and I am very well aware of the consistency aspect. Should have mentioned it, sorry. I do prefer to separate shading as a way to interact with light and environment (shader nodes) with material (mix of shader nodes given certain inputs possibly textures). So in my view a PBR shader is basically how the shaders are set up (i.e. diffuse and glossy) and the rules governing them (reduction of fresnel by roughness, handling AO inputs etc). Then this PBR shader can be used to create pretty much any material. So I prefer plastic and wood materials over plastic and wood shaders. But that may just be me.

But I disagree that PBR should be used for everything. The cost of forcing in glossy, although more physically correct and better visuals, in some cases cannot compete with the speed increase obtained from a pure diffuse. Or other tricks required to get rendering time down, noise or fireflies down, or to maintain a simpler workflow in post. I’m a huge fan of it, but it isn’t everything.