Physically Based Rendering Model

Trial provides a standard renderer that implements a Physically Based Rendering shading model and associated material. To use it, simply enter a pbr-render-pass and ensure your objects provide a pbr-material, or some appropriate conversion exists.

The model uses a Cook-Torrance BRDF to implement the shading behaviour, and it is recommended to use it in combination with an HDR pipeline.

Material Properties

Each material has the following properties:

Metalness increases towards the top, roughness towards the right

Image Based Lighting

The PBR renderer supports an image based lighting workflow. For this purpose it provides a special light type, the environment-light. The light requires an environment-map instance as the :asset initarg, which it uses to get the needed irradiance and prefiltered environment maps.

When the light is active in the scene it will provide ambient lighting for all objects based on the environment map. You can optionally control for its strength via the light's color, which simply acts as a multiplier.


Tone Mapping

By default the PBR renderer outputs colour in high dynamic range. This will make it look odd, unless you tone map the colours back into low dynamic range. To do so, you should add an instance of a tone-mapping-pass subclass and connect it to the color output of the PBR pass. The following tone mappers are implemented:

All tone mappers also include a gamma factor that should be adjusted according to the user's screen.