Johan Lagesson GAD: BA2 - Physically Based Shaders

Since I will be creating one of my textures in Substance Painter, I decided to research in Physically Based Rendering. When I researched it I come upon Physically Based Shaders as well and was interested to see the difference between the two, so I ended up researching both. First off is Physics Based Shaders. I found an hour long presentation by Naughty Dog where they presented how they use PBS in Uncharted 4. It can be found here: https://www.youtube.com/watch?v=wdUxLsNfLls

Since my main focus was PBR and not PBS i decided to mainly just take notes, most of the pictures used in my notes comes from the Presentation itself.

What is a Shader?

Shaders could be described as a more technically approach to Texturing. As an example, instead of painting in the detail in Photoshop you can by the help of a shader, generate a specific pattern onto a texture by the help of code.

Why is Physically Based Shading important?

Your brain can tell what’s real or not, usually by changes in light and angles. If the light does not react the way you think it would from a angle then we can tell it’s fake.

What is Physically Based Shading?

PBS is built upon these pillars: Reflection, Refraction, Fresnel, Microfacet, Subsurface.

To achieve movie look:

Reproduce all the shading features in an engine to look as close to real-life as possible.
Define the different materials using different rendering/shading techniques.

Shader Package

With this, if they want to add details such as sand, blood, sweat etc to their character/assets all they have to do is adjust the agent’s (Connect the box which have the feature they want to their asset) and from there adjust settings. This way they can add this very smooth and easy for artists.

Examples of shader packages and their uses:

Clothing/Assets/Materials: Fabric Texture, fabric aging, stitches, blood, dirt, mud, etc.