So for a friends (https://twitter.com/DeadSharkMartin) and mine (https://twitter.com/DeadSharkAndre) last assignment in school we decided to study PBR and how it can come to affect a 3D-artists work. We didn’t really want to go that far into programing and the technical stuff, just how it affects us a artists. We just wanted to share some quick thoughts we had working with PBR.
First off. Here is a fly-through and some screenshots of the scene we made.
There is still some small tweaks we want to do to the scene.
We first want to point out that this is our thoughts and opinions about PBR and may not be correct. We used articles such as Marmoset’s “PBR practise” (Tutorials & Resources | Marmoset) and Naty Hoffman’s SIGGRAPH presentation (http://renderwonk.com/publications/s2010-shading-course/hoffman/s2010_physically_based_shading_hoffman_a_notes.pdf) as a ground to stand on and form our own opinions about PBR.
So, our experience consists of 3 years of college working with “traditional observation based shading”. The “traditional observation based shading” is a term we saw Nicolas Schulz (Home - Making Games) use in his article about PBR. We really liked this term because we could really related to it. The traditional method of using diffuse, specular and gloss is based on the 3D-artist subjective point of view of how a material should look.
When learning PBR we really suggest that you research 3 principles from physics. These will help you a lot understanding and working with PBR. The 3 principles are:
- Subsurface scattering (what happens to the light when it hits a surface)
- Energy conservation
These 3 principles are really important to understand and you can read about them hereor here
When we started reading about how other companies had implemented PBR into their workflow one thing was really common. It was that the artist had a hard time addapting to PBR. When we started working with PBR we couldn’t really relate to this. We think that the reason behind this is that we read up a lot about PBR and the 3 principles before even started working with PBR. So our recommendation to you if you want to start working with PBR is to read up on these 3 principles.
So, starting working with PBR we were at first concerned about the specular and gloss being combined into roughness. We thought this would decrease the control we had over the material. But upon using it in practise it really made sense and we could relate back to the principle of energy conservation.
A goal that was very common across all the articles we read was that is should be easier to achieve a consistency. Working with PBR we noticed that this was true. We had an easier time adapting to each other. There was also a consistency with different lights, that is a big point using PBR. We no longer had to adapt our textures or materials depending on what kind of lighting they were in. Even though our scene we made is quite small it helped us a lot and saved us a lot of time when we did the night lighting.
What we noticed that really saved us time was the usage of predefined value for the roughness. This will be even more awesome when we will have a broad number of different materials and measured values.
If you have any question about PBR feel free to ask (we are not technically masterminds and doesn’t really know the programming and stuff behind it though).