Function mallumo::build_brdf

pub fn build_brdf(
    distribution: Option<&str>, 
    fresnel: Option<&str>, 
    geometry: Option<&str>
) -> String

Builds irradiance() function in glsl.

vec3 irradiance(vec3 N, vec3 H, vec3 V, vec3 L, vec3 radiance, vec4 albedo, float roughness, float metalness) where N is normal vector H is half vector L is light vector radiance is color of light albedo, roughness, metalness are object pbr parameters

You can provide distribution, fresnel and geometry functions for Cook-Torrance BRDF, if not default functions are provided.

float cook_torrance_distribution(vec3 N, vec3 H, float roughness) where N is normal vector H is half vector roughness is object pbr parameter

vec3 cook_torrance_fresnel(float VdotH, vec3 f0) where VdotH is dot product of view and half vectors / cosine of angle between view and half vectors f0 is material's response at normal incidence

float cook_torrance_geometry(vec3 N, vec3 V, vec3 L, float roughness) where N is normal vector V is view vector L is light vector roughness is object pbr parameter