Rejig deferred normal-map packing a little, to double its accuracy for free.

1 files changed, 6 insertions, 4 deletions

diff --git a/indra/newview/app_settings/shaders/class3/deferred/giDownsampleF.glsl b/indra/newview/app_settings/shaders/class3/deferred/giDownsampleF.glsl
index 7325825d6d..66606233cd 100644
--- a/indra/newview/app_settings/shaders/class3/deferred/giDownsampleF.glsl
+++ b/indra/newview/app_settings/shaders/class3/deferred/giDownsampleF.glsl
@@ -44,7 +44,8 @@ float getDepth(vec2 pos_screen)
 
 void main() 
 {
-	vec3 norm = texture2DRect(normalMap, vary_fragcoord.xy).xyz*2.0-1.0;
+	vec3 norm = texture2DRect(normalMap, vary_fragcoord.xy).xyz;
+	norm = vec3((norm.xy-0.5)*2.0,norm.z); // unpack norm
 	float depth = getDepth(vary_fragcoord.xy);
 		
 	vec3 ccol = texture2DRect(giLightMap, vary_fragcoord.xy).rgb;
@@ -56,9 +57,10 @@ void main()
 	for (int i = 0; i < kern_length; i++)
 	{
 		vec2 tc = vary_fragcoord.xy + kern[i].y*dlt;
-	    vec3 sampNorm = texture2DRect(normalMap, tc.xy).xyz*2.0-1.0;
-	    
-	   float d = dot(norm.xyz, sampNorm);
+		vec3 sampNorm = texture2DRect(normalMap, tc.xy).xyz;
+		sampNorm = vec3((sampNorm.xy-0.5)*2.0,sampNorm.z); // unpack norm
+		
+		float d = dot(norm.xyz, sampNorm);
 		
 		if (d > 0.5)
 		{