RenderingOpenGL2: Fixed final blending of vtkOrderIndependentTranslucentPass.

Rendering/OpenGL2/glsl/vtkOrderIndependentTranslucentPassFinalFS.glsl

@@ -16,7 +16,7 @@ void main()
   vec4 t1Color = texture(translucentRGBATexture, texCoord);
   float t2Color = texture(translucentRTexture, texCoord).r;
 
-  gl_FragData[0] = vec4(t1Color.rgb/max(t2Color,0.01), t1Color.a);
+  gl_FragData[0] = vec4(t1Color.rgb/max(t2Color,0.01), 1.0-t1Color.a);
   // gl_FragData[0] = vec4(t1Color.a, t1Color.a, t1Color.a, 0.0);
   // gl_FragData[0] = vec4(t2Color, t2Color, t2Color, 0.0);
 }

Rendering/OpenGL2/vtkOrderIndependentTranslucentPass.cxx

@@ -325,8 +325,9 @@ void vtkOrderIndependentTranslucentPass::Render(const vtkRenderState* s)
   // back to the original FO
   this->State->PopFramebufferBindings();
 
+  // Restore blending parameters:
   this->State->vtkglBlendFuncSeparate(
-    GL_ONE_MINUS_SRC_ALPHA, GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_SRC_ALPHA);
+    GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
 
   // Restore the original viewport and scissor test settings
   this->State->vtkglViewport(
@@ -359,10 +360,6 @@ void vtkOrderIndependentTranslucentPass::Render(const vtkRenderState* s)
   }
 #endif
 
-  // Restore blending parameters:
-  this->State->vtkglBlendFuncSeparate(
-    GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA, GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
-
   this->PostRender(s);
 
   this->NumberOfRenderedProps = this->TranslucentPass->GetNumberOfRenderedProps();