feat: refactor towards standard BRDF form (incoming irradiance to out…

…put radiance)
bhouston · Jul 27, 2020 · 2dc16f7 · 2dc16f7
1 parent 8e9eaf3
commit 2dc16f7
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Showing 27 changed files with 165 additions and 109 deletions.
diff --git a/src/examples/brdfs/clearcoat/fragment.glsl b/src/examples/brdfs/clearcoat/fragment.glsl
@@ -5,7 +5,7 @@ varying vec3 v_viewSurfaceNormal;
 varying vec2 v_uv0;
 
 uniform vec3 pointLightViewPosition;
-uniform vec3 pointLightColor;
+uniform vec3 pointLightIntensity;
 uniform float pointLightRange;
 
 uniform sampler2D albedoMap;
@@ -41,21 +41,27 @@ void main() {
 
   PunctualLight punctualLight;
   punctualLight.position = pointLightViewPosition;
-  punctualLight.color = pointLightColor;
+  punctualLight.intensity = pointLightIntensity;
   punctualLight.range = pointLightRange;
 
   DirectLight directLight;
   pointLightToDirectLight( surface, punctualLight, directLight );
 
   vec3 lightDirection = directLight.lightDirection;
-  vec3 irradiance = directLight.irradiance;
+  vec3 lightRadiance = directLight.radiance;
 
-  vec3 outputColor;
-  outputColor += irradiance * BRDF_Specular_GGX( clearCoatSurface, lightDirection, clearCoatF0, clearCoatRoughness );
-  outputColor += irradiance * BRDF_Specular_GGX( surface, lightDirection, specularF0, specularRoughness );
-  outputColor += irradiance * BRDF_Diffuse_Lambert( albedo );
+  float clearCoatNormalFluxRatio = saturate( dot( lightDirection, clearCoatSurface.normal ) );
+  float normalFluxRatio = saturate( dot( lightDirection, surface.normal ) );
 
-  gl_FragColor.rgb = linearTosRGB( outputColor );
+  vec3 outgoingRadiance;
+  outgoingRadiance += lightRadiance * clearCoatNormalFluxRatio *
+    BRDF_Specular_GGX( clearCoatSurface, lightDirection, clearCoatF0, clearCoatRoughness ) ;
+  outgoingRadiance += lightRadiance * normalFluxRatio *
+    BRDF_Specular_GGX( surface, lightDirection, specularF0, specularRoughness ) ;
+  outgoingRadiance += lightRadiance * normalFluxRatio *
+    BRDF_Diffuse_Lambert( albedo );
+
+  gl_FragColor.rgb = linearTosRGB( outgoingRadiance );
   gl_FragColor.a = 1.;
 
 }
diff --git a/src/examples/brdfs/clearcoat/index.ts b/src/examples/brdfs/clearcoat/index.ts
@@ -43,7 +43,7 @@ async function init(): Promise<null> {
 
     // lights
     pointLightViewPosition: new Vector3(0.0, 0, 0.0),
-    pointLightColor: new Vector3(1, 1, 1).multiplyByScalar(30.0),
+    pointLightIntensity: new Vector3(1, 1, 1).multiplyByScalar(30.0),
     pointLightRange: 6.0,
 
     // materials

diff --git a/src/examples/brdfs/lambert/fragment.glsl b/src/examples/brdfs/lambert/fragment.glsl
@@ -5,7 +5,7 @@ varying vec3 v_viewSurfaceNormal;
 varying vec2 v_uv0;
 
 uniform vec3 pointLightViewPosition;
-uniform vec3 pointLightColor;
+uniform vec3 pointLightIntensity;
 uniform float pointLightRange;
 
 uniform vec3 albedoModulator;
@@ -23,7 +23,7 @@ void main() {
   PunctualLight punctualLight;
   punctualLight.type = LightType_Point;
   punctualLight.position = pointLightViewPosition;
-  punctualLight.color = pointLightColor;
+  punctualLight.intensity = pointLightIntensity;
   punctualLight.direction = vec3(0.);
   punctualLight.range = pointLightRange;
   punctualLight.innerConeCos = 0.;
@@ -37,12 +37,15 @@ void main() {
   pointLightToDirectLight( surface, punctualLight, directLight );
 
   vec3 lightDirection = directLight.lightDirection;
-  vec3 irradiance = directLight.irradiance;
+  vec3 lightRadiance = directLight.radiance;
 
-  vec3 outputColor;
-  outputColor += irradiance * BRDF_Diffuse_Lambert( albedo );
+  float normalFluxRatio = saturate( dot( lightDirection, surface.normal ) );
 
-  gl_FragColor.rgb = linearTosRGB( outputColor );
+  vec3 outgoingRadiance;
+  outgoingRadiance += lightRadiance * normalFluxRatio *
+    BRDF_Diffuse_Lambert( albedo );
+
+  gl_FragColor.rgb = linearTosRGB( outgoingRadiance );
   gl_FragColor.a = 1.;
 
 }
diff --git a/src/examples/brdfs/lambert/index.ts b/src/examples/brdfs/lambert/index.ts
@@ -40,7 +40,7 @@ async function init(): Promise<null> {
 
     // lights
     pointLightViewPosition: new Vector3(1, 0, -0.5),
-    pointLightColor: new Vector3(1, 1, 1).multiplyByScalar(40.0),
+    pointLightIntensity: new Vector3(1, 1, 1).multiplyByScalar(40.0),
     pointLightRange: 6.0,
 
     // materials

diff --git a/src/examples/brdfs/sheen/fragment.glsl b/src/examples/brdfs/sheen/fragment.glsl
@@ -5,7 +5,7 @@ varying vec3 v_viewSurfaceNormal;
 varying vec2 v_uv0;
 
 uniform vec3 pointLightViewPosition;
-uniform vec3 pointLightColor;
+uniform vec3 pointLightIntensity;
 uniform float pointLightRange;
 
 uniform vec3 sheenColor;
@@ -36,21 +36,26 @@ void main() {
 
   PunctualLight punctualLight;
   punctualLight.position = pointLightViewPosition;
-  punctualLight.color = pointLightColor;
+  punctualLight.intensity = pointLightIntensity;
   punctualLight.range = pointLightRange;
 
   DirectLight directLight;
   pointLightToDirectLight( surface, punctualLight, directLight );
 
   vec3 lightDirection = directLight.lightDirection;
-  vec3 irradiance = directLight.irradiance;
+  vec3 lightRadiance = directLight.radiance;
 
-  vec3 outputColor;
-  outputColor += irradiance * BRDF_Sheen_Charlie( surface, lightDirection, sheenColor, sheenIntensity, sheenRoughness );
-  outputColor += (1. - sheenIntensity ) * irradiance * BRDF_Specular_GGX( surface, lightDirection, specularF0, specularRoughness );
-  outputColor += irradiance * BRDF_Diffuse_Lambert( albedo );
+  float normalFluxRatio = saturate( dot( lightDirection, surface.normal ) );
 
-  gl_FragColor.rgb = linearTosRGB( outputColor );
+  vec3 outgoingRadiance;
+  outgoingRadiance += lightRadiance * normalFluxRatio *
+    BRDF_Sheen_Charlie( surface, lightDirection, sheenColor, sheenIntensity, sheenRoughness ) ;
+  outgoingRadiance +=  (1. - sheenIntensity ) * lightRadiance * normalFluxRatio *
+    BRDF_Specular_GGX( surface, lightDirection, specularF0, specularRoughness ) ;
+  outgoingRadiance += lightRadiance * normalFluxRatio *
+    BRDF_Diffuse_Lambert( albedo );
+
+  gl_FragColor.rgb = linearTosRGB( outgoingRadiance );
   gl_FragColor.a = 1.;
 
 }
diff --git a/src/examples/brdfs/sheen/index.ts b/src/examples/brdfs/sheen/index.ts
@@ -46,7 +46,7 @@ async function init(): Promise<null> {
 
     // lights
     pointLightViewPosition: new Vector3(0.0, 0, 0.0),
-    pointLightColor: new Vector3(1, 1, 1).multiplyByScalar(30.0),
+    pointLightIntensity: new Vector3(1, 1, 1).multiplyByScalar(30.0),
     pointLightRange: 6.0,
 
     // materials

diff --git a/src/examples/brdfs/specular/fragment.glsl b/src/examples/brdfs/specular/fragment.glsl
@@ -5,7 +5,7 @@ varying vec3 v_viewSurfaceNormal;
 varying vec2 v_uv0;
 
 uniform vec3 pointLightViewPosition;
-uniform vec3 pointLightColor;
+uniform vec3 pointLightIntensity;
 uniform float pointLightRange;
 
 uniform vec3      albedoModulator;
@@ -35,20 +35,24 @@ void main() {
 
   PunctualLight punctualLight;
   punctualLight.position = pointLightViewPosition;
-  punctualLight.color = pointLightColor;
+  punctualLight.intensity = pointLightIntensity;
   punctualLight.range = pointLightRange;
 
   DirectLight directLight;
   pointLightToDirectLight( surface, punctualLight, directLight );
 
   vec3 lightDirection = directLight.lightDirection;
-  vec3 irradiance = directLight.irradiance;
+  vec3 lightRadiance = directLight.radiance;
 
-  vec3 outputColor;
-  outputColor += irradiance * BRDF_Specular_GGX( surface, lightDirection, specularF0, specularRoughness );
-  outputColor += irradiance * BRDF_Diffuse_Lambert( albedo );
+  float normalFluxRatio = saturate( dot( lightDirection, surface.normal ) );
 
-  gl_FragColor.rgb = linearTosRGB( outputColor );
+  vec3 outgoingRadiance;
+  outgoingRadiance += lightRadiance * normalFluxRatio *
+    BRDF_Specular_GGX( surface, lightDirection, specularF0, specularRoughness ) ;
+  outgoingRadiance += lightRadiance * normalFluxRatio *
+    BRDF_Diffuse_Lambert( albedo );
+
+  gl_FragColor.rgb = linearTosRGB( outgoingRadiance );
   gl_FragColor.a = 1.;
 
 }
diff --git a/src/examples/brdfs/specular/index.ts b/src/examples/brdfs/specular/index.ts
@@ -41,7 +41,7 @@ async function init(): Promise<null> {
 
     // lights
     pointLightViewPosition: new Vector3(1, 0, -0.5),
-    pointLightColor: new Vector3(1, 1, 1).multiplyByScalar(40.0),
+    pointLightIntensity: new Vector3(1, 1, 1).multiplyByScalar(40.0),
     pointLightRange: 6.0,
 
     // materials

diff --git a/src/examples/brdfs/specularAnisotropic/fragment.glsl b/src/examples/brdfs/specularAnisotropic/fragment.glsl
@@ -5,7 +5,7 @@ varying vec3 v_viewSurfaceNormal;
 varying vec2 v_uv0;
 
 uniform vec3 pointLightViewPosition;
-uniform vec3 pointLightColor;
+uniform vec3 pointLightIntensity;
 uniform float pointLightRange;
 
 uniform float     specularAnisotropicScale;
@@ -36,7 +36,7 @@ void main() {
 
   PunctualLight punctualLight;
   punctualLight.position = pointLightViewPosition;
-  punctualLight.color = pointLightColor;
+  punctualLight.intensity = pointLightIntensity;
   punctualLight.range = pointLightRange;
 
   specularAnisotropicBentNormal( surface, length( specularAnisotropicFlow ), specularRoughness );
@@ -45,13 +45,17 @@ void main() {
   pointLightToDirectLight( surface, punctualLight, directLight );
 
   vec3 lightDirection = directLight.lightDirection;
-  vec3 irradiance = directLight.irradiance;
+  vec3 lightRadiance = directLight.radiance;
 
-  vec3 outputColor;
-  outputColor += irradiance * BRDF_Specular_GGX( surface, lightDirection, specularF0, specularRoughness );
-  outputColor += irradiance * BRDF_Diffuse_Lambert( albedo );
+  float normalFluxRatio = saturate( dot( lightDirection, surface.normal ) );
 
-  gl_FragColor.rgb = linearTosRGB( outputColor );
+  vec3 outgoingRadiance;
+  outgoingRadiance += lightRadiance * normalFluxRatio *
+    BRDF_Specular_GGX( surface, lightDirection, specularF0, specularRoughness ) ;
+  outgoingRadiance += lightRadiance * normalFluxRatio *
+    BRDF_Diffuse_Lambert( albedo );
+
+  gl_FragColor.rgb = linearTosRGB( outgoingRadiance );
   gl_FragColor.a = 1.;
 
 }
diff --git a/src/examples/brdfs/specularAnisotropic/index.ts b/src/examples/brdfs/specularAnisotropic/index.ts
@@ -45,7 +45,7 @@ async function init(): Promise<null> {
 
     // lights
     pointLightViewPosition: new Vector3(0.0, 0, 0.0),
-    pointLightColor: new Vector3(1, 1, 1).multiplyByScalar(0.7),
+    pointLightIntensity: new Vector3(1, 1, 1).multiplyByScalar(0.7),
     pointLightRange: 12.0,
 
     // materials

diff --git a/src/examples/lights/directional/fragment.glsl b/src/examples/lights/directional/fragment.glsl
@@ -33,19 +33,23 @@ void main() {
 
   PunctualLight punctualLight;
   punctualLight.direction = directionalLightViewDirection;
-  punctualLight.color = directionalLightColor;
+  punctualLight.intensity = directionalLightColor;
 
   DirectLight directLight;
   directionalLightToDirectLight( surface, punctualLight, directLight );
 
   vec3 lightDirection = directLight.lightDirection;
-  vec3 irradiance = directLight.irradiance;
+  vec3 lightRadiance = directLight.radiance;
 
-  vec3 outputColor;
-  outputColor += irradiance * BRDF_Specular_GGX( surface, lightDirection, specularF0, specularRoughness );
-  outputColor += irradiance * BRDF_Diffuse_Lambert( albedo );
+  float normalFluxRatio = saturate( dot( lightDirection, surface.normal ) );
 
-  gl_FragColor.rgb = linearTosRGB( outputColor );
+  vec3 outgoingRadiance;
+  outgoingRadiance += lightRadiance * normalFluxRatio *
+    BRDF_Specular_GGX( surface, lightDirection, specularF0, specularRoughness ) ;
+  outgoingRadiance += lightRadiance * normalFluxRatio *
+    BRDF_Diffuse_Lambert( albedo );
+
+  gl_FragColor.rgb = linearTosRGB( outgoingRadiance );
   gl_FragColor.a = 1.;
 
 }
diff --git a/src/examples/lights/multi/fragment.glsl b/src/examples/lights/multi/fragment.glsl
@@ -38,7 +38,7 @@ void main() {
 
   uvToTangentFrame( surface, v_uv0 );
 
-  vec3 outputColor;
+  vec3 outgoingRadiance;
 
   for( int i = 0; i < MAX_PUNCTUAL_LIGHTS; i ++ ) {
 
@@ -48,7 +48,7 @@ void main() {
     punctualLight.type = punctualLightType[i];
     punctualLight.position = punctualLightViewPosition[i];
     punctualLight.direction = punctualLightViewDirection[i];
-    punctualLight.color = punctualLightColor[i];
+    punctualLight.intensity = punctualLightColor[i];
     punctualLight.range = punctualLightRange[i];
     punctualLight.innerConeCos = punctualLightInnerCos[i];
     punctualLight.outerConeCos = punctualLightOuterCos[i];
@@ -65,14 +65,18 @@ void main() {
     }
 
     vec3 lightDirection = directLight.lightDirection;
-    vec3 irradiance = directLight.irradiance;
+    vec3 lightRadiance = directLight.radiance;
 
-    outputColor += irradiance * BRDF_Specular_GGX( surface, lightDirection, specularF0, specularRoughness );
-    outputColor += irradiance * BRDF_Diffuse_Lambert( albedo );
+    float normalFluxRatio = saturate( dot( lightDirection, surface.normal ) );
+
+    outgoingRadiance += lightRadiance * normalFluxRatio *
+      BRDF_Specular_GGX( surface, lightDirection, specularF0, specularRoughness ) ;
+    outgoingRadiance += lightRadiance * normalFluxRatio *
+      BRDF_Diffuse_Lambert( albedo );
 
   }
 
-  gl_FragColor.rgb = linearTosRGB( outputColor );
+  gl_FragColor.rgb = linearTosRGB( outgoingRadiance );
   gl_FragColor.a = 1.;
 
 }
diff --git a/src/examples/lights/point/fragment.glsl b/src/examples/lights/point/fragment.glsl
@@ -5,7 +5,7 @@ varying vec3 v_viewSurfaceNormal;
 varying vec2 v_uv0;
 
 uniform vec3 pointLightViewPosition;
-uniform vec3 pointLightColor;
+uniform vec3 pointLightIntensity;
 uniform float pointLightRange;
 
 uniform vec2      normalModulator;
@@ -38,20 +38,24 @@ void main() {
 
   PunctualLight punctualLight;
   punctualLight.position = pointLightViewPosition;
-  punctualLight.color = pointLightColor;
+  punctualLight.intensity = pointLightIntensity;
   punctualLight.range = pointLightRange;
 
   DirectLight directLight;
   pointLightToDirectLight( surface, punctualLight, directLight );
 
   vec3 lightDirection = directLight.lightDirection;
-  vec3 irradiance = directLight.irradiance;
+  vec3 lightRadiance = directLight.radiance;
 
-  vec3 outputColor;
-  outputColor += irradiance * BRDF_Specular_GGX( surface, lightDirection, specularF0, specularRoughness );
-  outputColor += irradiance * BRDF_Diffuse_Lambert( albedo );
+  float normalFluxRatio = saturate( dot( lightDirection, surface.normal ) );
 
-  gl_FragColor.rgb = linearTosRGB( outputColor );
+  vec3 outgoingRadiance;
+  outgoingRadiance += lightRadiance * normalFluxRatio *
+    BRDF_Specular_GGX( surface, lightDirection, specularF0, specularRoughness ) ;
+  outgoingRadiance += lightRadiance * normalFluxRatio *
+    BRDF_Diffuse_Lambert( albedo );
+
+  gl_FragColor.rgb = linearTosRGB( outgoingRadiance );
   gl_FragColor.a = 1.;
 
 }
diff --git a/src/examples/lights/point/index.ts b/src/examples/lights/point/index.ts
@@ -42,7 +42,7 @@ async function init(): Promise<null> {
 
     // lights
     pointLightViewPosition: new Vector3(0.0, 0, 0.0),
-    pointLightColor: new Vector3(1, 1, 1).multiplyByScalar(30.0),
+    pointLightIntensity: new Vector3(1, 1, 1).multiplyByScalar(30.0),
     pointLightRange: 6.0,
 
     // materials