Unified renderer OSA sample clipping:

User info:
	This change limits the contribution of any OSA sample to 1.0 per color
	in the Unified renderer.  Because color=1.0 gives fully saturated color,
	samples contributing more than 1.0 were overweighted in the OSA average
	causing aliasing (sometimes quite severe).

	Samples can contribute more than 1.0 because a material's spec and refl
	values are not normalized (In real world spec+refl <= 1.0).  This solves
	a large class of aliasing problems in the unified renderer.

Coder Info:
	None.

1 files changed, 7 insertions, 5 deletions

diff --git a/source/blender/render/intern/source/pixelblending.c b/source/blender/render/intern/source/pixelblending.c
index 338e60e6be8..c1bd67c7479 100644
--- a/source/blender/render/intern/source/pixelblending.c
+++ b/source/blender/render/intern/source/pixelblending.c
@@ -618,9 +618,9 @@ void sampleFloatColV2FloatColV(float *sample, float *dest, int osaNr)
 	if (doGamma()) {
 		/* use a LUT and interpolation to do the gamma correction */
 		for(a=0; a < osaNr; a++, scol+=4) {
-			intcol[0] += gammaCorrect(scol[0]); 
-			intcol[1] += gammaCorrect(scol[1]); 
-			intcol[2] += gammaCorrect(scol[2]); 
+			intcol[0] += gammaCorrect( (scol[0]<1.0) ? scol[0]:1.0 ); 
+			intcol[1] += gammaCorrect( (scol[1]<1.0) ? scol[1]:1.0 ); 
+			intcol[2] += gammaCorrect( (scol[2]<1.0) ? scol[2]:1.0 ); 
 			intcol[3] += scol[3];
 		}
 
@@ -638,8 +638,10 @@ void sampleFloatColV2FloatColV(float *sample, float *dest, int osaNr)
 	} else {
 		/* no gamma */
 		for(a=0; a < osaNr; a++, scol+=4) {
-			intcol[0] += scol[0]; intcol[1] += scol[1];
-			intcol[2] += scol[2]; intcol[3] += scol[3];
+			intcol[0] += (scol[0]<1.0) ? scol[0]:1.0 ; 
+			intcol[1] += (scol[1]<1.0) ? scol[1]:1.0 ;
+			intcol[2] += (scol[2]<1.0) ? scol[2]:1.0 ; 
+			intcol[3] += scol[3];
 		}
     
 		dest[0]= intcol[0]/osaNr;