fix: fix black fringes: V-Ray PNGs are actually premultipled alpha ag…

…ainst PNG spec.
bhouston · Oct 27, 2020 · e74490d · e74490d
1 parent 8e77d45
commit e74490d
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Showing 3 changed files with 9 additions and 8 deletions.
diff --git a/src/lib/engines/layerCompositor/Layer.ts b/src/lib/engines/layerCompositor/Layer.ts
@@ -19,7 +19,6 @@ export class Layer {
     public offset: Vector2,
     public uvScaleFactor = new Vector2(1, -1),
     public uvOffset = new Vector2(0, 1),
-    public premultipliedAlpha = true,
   ) {
     // console.log(`Layer: size ( ${texImage2D.size.x}, ${texImage2D.size.y} ) `);
 

diff --git a/src/lib/engines/layerCompositor/LayerCompositor.ts b/src/lib/engines/layerCompositor/LayerCompositor.ts
@@ -224,7 +224,7 @@ export class LayerCompositor {
     );
     const uvToTexture = makeMatrix3Concatenation(uvTranslation, uvScale);
 
-    canvasFramebuffer.clearState = this.clearState; // new ClearState(new Vector3(1, 1, 1), 0.0);
+    canvasFramebuffer.clearState = new ClearState(new Vector3(0, 0, 0), 0.0);
     canvasFramebuffer.clear();
 
     const offscreenColorAttachment = this.offscreenColorAttachment;
@@ -280,10 +280,10 @@ export class LayerCompositor {
         layerMap: layer.texImage2D,
         uvToTexture: layer.uvToTexture,
         mipmapBias: 0,
-        premultipliedAlpha: layer.premultipliedAlpha ? 1 : 0,
+        premultipliedAlpha: 0,
       };
 
-      const blendState = blendModeToBlendState(Blending.Over, layer.premultipliedAlpha);
+      const blendState = blendModeToBlendState(Blending.Over, true);
 
       // console.log(`drawing layer #${index}: ${layer.url} at ${layer.offset.x}, ${layer.offset.y}`);
       renderBufferGeometry(offscreenFramebuffer, this.#program, uniforms, this.#bufferGeometry, undefined, blendState);

diff --git a/src/lib/engines/layerCompositor/fragment.glsl b/src/lib/engines/layerCompositor/fragment.glsl
@@ -12,18 +12,20 @@ varying vec3 v_viewPosition;
 varying vec3 v_viewNormal;
 varying vec2 v_uv;
 
+#pragma include <math/math>
 #pragma include <color/spaces/srgb>
 
 void main() {
   vec3 outputColor = vec3(0.);
   vec2 texelUv = ( uvToTexture * vec3( v_uv, 1.0 ) ).xy;
+
   vec4 layerColor = texture2D( layerMap, texelUv, mipmapBias );
-  outputColor += sRGBToLinear( layerColor.rgb );
 
-  gl_FragColor.rgb = linearTosRGB( outputColor );
+  // premultiply alpha in output as the source PNG is not premultiplied
   if( premultipliedAlpha == 1 ) {
-    gl_FragColor.rgb *= layerColor.a;
+    layerColor.rgb *= layerColor.a;
   }
-  gl_FragColor.a = layerColor.a;
+
+  gl_FragColor = layerColor;
 
 }