Unit CastleLoadGltf

Makes model loaded from glTF use Phong materials (TMaterialNode) instead of Physically-Based Rendering materials (TPhysicalMaterialNode).

Phong is a worse lighting model in general (less realistic, and most authoring tools now expose parameters closer to PBR, like Blender). However Phong lighting model is cheaper to compute, and it allows both Gouraud and Phong shading. And Phong lighting model combined with Gouraud shading is very cheap to render, which in effect means that your models render fast.

We just interpret glTF pbrMetallicRoughness parameter "baseColor" (RGB part) as Phong "diffuseColor".