PBR Lighting issue #2330
Description
To continue the discussion from:
https://hub.jmonkeyengine.org/t/zombiegirl-gltfloader-vs-monkeywrench/48007/15
Summary:
According to gltf specs, and on the reference viewers, the default value for metallic factor is 1. Jme's importers are setting the metallic factor to 0 to pass the test cases. The problematic line in my opinion is:
//223 of PBRLighting
vec4 diffuseColor = albedo - albedo * Metallic;
I have checked, a few other repositories, and i have not yet found that piece of math again. Additionally, the whole block:
float specular = 0.5;
float nonMetalSpec = 0.08 * specular;
vec4 specularColor = (nonMetalSpec - nonMetalSpec * Metallic) + albedo * Metallic;
vec4 diffuseColor = albedo - albedo * Metallic;
vec3 fZero = vec3(specular);
is quite unique. F0 is in all other shaders defined as:
vec3 F0 = vec3(0.04);
F0 = mix(F0, albedo, metallic);