Merge pull request #69522 from clayjohn/IBL-black-metal

Allow black metallic materials to reflect IBL

drivers/gles3/shaders/scene.glsl

@@ -1162,7 +1162,7 @@ void main() {
 
 		float a004 = min(r.x * r.x, exp2(-9.28 * ndotv)) * r.x + r.y;
 		vec2 env = vec2(-1.04, 1.04) * a004 + r.zw;
-		specular_light *= env.x * f0 + env.y * clamp(50.0 * f0.g, 0.0, 1.0);
+		specular_light *= env.x * f0 + env.y * clamp(50.0 * f0.g, metallic, 1.0);
 #endif
 	}
 

servers/rendering/renderer_rd/shaders/forward_clustered/scene_forward_clustered.glsl

@@ -1485,7 +1485,7 @@ void fragment_shader(in SceneData scene_data) {
 		float a004 = min(r.x * r.x, exp2(-9.28 * ndotv)) * r.x + r.y;
 		vec2 env = vec2(-1.04, 1.04) * a004 + r.zw;
 
-		specular_light *= env.x * f0 + env.y * clamp(50.0 * f0.g, 0.0, 1.0);
+		specular_light *= env.x * f0 + env.y * clamp(50.0 * f0.g, metallic, 1.0);
 #endif
 	}
 

servers/rendering/renderer_rd/shaders/forward_mobile/scene_forward_mobile.glsl

@@ -1205,7 +1205,7 @@ void main() {
 		float a004 = min(r.x * r.x, exp2(-9.28 * ndotv)) * r.x + r.y;
 		vec2 env = vec2(-1.04, 1.04) * a004 + r.zw;
 
-		specular_light *= env.x * f0 + env.y;
+		specular_light *= env.x * f0 + env.y * clamp(50.0 * f0.g, metallic, 1.0);
 #endif
 	}
 

servers/rendering/renderer_rd/shaders/scene_forward_lights_inc.glsl

@@ -202,7 +202,7 @@ void light_compute(vec3 N, vec3 L, vec3 V, float A, vec3 light_color, float atte
 		float cLdotH5 = SchlickFresnel(cLdotH);
 		// Calculate Fresnel using specular occlusion term from Filament:
 		// https://google.github.io/filament/Filament.html#lighting/occlusion/specularocclusion
-		float f90 = clamp(dot(f0, vec3(50.0 * 0.33)), 0.0, 1.0);
+		float f90 = clamp(dot(f0, vec3(50.0 * 0.33)), metallic, 1.0);
 		vec3 F = f0 + (f90 - f0) * cLdotH5;
 
 		vec3 specular_brdf_NL = cNdotL * D * F * G;