From 395ef525b12a044d7e70a1fba57ca1de2f11c1e3 Mon Sep 17 00:00:00 2001
From: Robert Beckebans <robert.beckebans@gmail.com>
Date: Thu, 19 Mar 2015 01:27:44 +0100
Subject: [PATCH] Tweaked shadowmap bias to fight shadow acne

---
 base/renderprogs/interactionSM.pixel | 6 ++++--
 neo/renderer/RenderProgs_embedded.h  | 6 ++++--
 neo/renderer/RenderSystem_init.cpp   | 2 ++
 neo/renderer/tr_backend_draw.cpp     | 2 +-
 neo/renderer/tr_local.h              | 2 ++
 5 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/base/renderprogs/interactionSM.pixel b/base/renderprogs/interactionSM.pixel
index 17c9ec8b..e261dc06 100644
--- a/base/renderprogs/interactionSM.pixel
+++ b/base/renderprogs/interactionSM.pixel
@@ -196,7 +196,9 @@ void main( PS_IN fragment, out PS_OUT result )
 	float bias = 0.001;
 	
 	shadowTexcoord.xyz /= shadowTexcoord.w;
-	shadowTexcoord.z = shadowTexcoord.z * 0.9995;
+	
+	shadowTexcoord.z = shadowTexcoord.z * rpScreenCorrectionFactor.w;
+	//shadowTexcoord.z = shadowTexcoord.z * 0.999991;
 	//shadowTexcoord.z = shadowTexcoord.z - bias;
 	shadowTexcoord.w = float(shadowIndex);
 
@@ -216,7 +218,7 @@ void main( PS_IN fragment, out PS_OUT result )
 	float shadow = 0.0;
 	
 	//float stepSize = 1.0 / 16.0;
-	float numSamples = rpScreenCorrectionFactor.w;
+	float numSamples = 16;
 	float stepSize = 1.0 / numSamples;
 	
 	float4 jitterTC = ( fragment.position * rpScreenCorrectionFactor ) + rpJitterTexOffset;
diff --git a/neo/renderer/RenderProgs_embedded.h b/neo/renderer/RenderProgs_embedded.h
index 579d41ea..cecce404 100644
--- a/neo/renderer/RenderProgs_embedded.h
+++ b/neo/renderer/RenderProgs_embedded.h
@@ -4389,7 +4389,9 @@ static const cgShaderDef_t cg_renderprogs[] =
 		"	float bias = 0.001;\n"
 		"	\n"
 		"	shadowTexcoord.xyz /= shadowTexcoord.w;\n"
-		"	shadowTexcoord.z = shadowTexcoord.z * 0.9995;\n"
+		"	\n"
+		"	shadowTexcoord.z = shadowTexcoord.z * rpScreenCorrectionFactor.w;\n"
+		"	//shadowTexcoord.z = shadowTexcoord.z * 0.999991;\n"
 		"	//shadowTexcoord.z = shadowTexcoord.z - bias;\n"
 		"	shadowTexcoord.w = float(shadowIndex);\n"
 		"\n"
@@ -4409,7 +4411,7 @@ static const cgShaderDef_t cg_renderprogs[] =
 		"	float shadow = 0.0;\n"
 		"	\n"
 		"	//float stepSize = 1.0 / 16.0;\n"
-		"	float numSamples = rpScreenCorrectionFactor.w;\n"
+		"	float numSamples = 16;\n"
 		"	float stepSize = 1.0 / numSamples;\n"
 		"	\n"
 		"	float4 jitterTC = ( fragment.position * rpScreenCorrectionFactor ) + rpJitterTexOffset;\n"
diff --git a/neo/renderer/RenderSystem_init.cpp b/neo/renderer/RenderSystem_init.cpp
index b4f12cba..150ca363 100644
--- a/neo/renderer/RenderSystem_init.cpp
+++ b/neo/renderer/RenderSystem_init.cpp
@@ -235,6 +235,8 @@ idCVar r_shadowMapLodBias( "r_shadowMapLodBias", "0", CVAR_RENDERER | CVAR_INTEG
 idCVar r_shadowMapPolygonFactor( "r_shadowMapPolygonFactor", "2", CVAR_RENDERER | CVAR_FLOAT, "polygonOffset factor for drawing shadow buffer" );
 idCVar r_shadowMapPolygonOffset( "r_shadowMapPolygonOffset", "3000", CVAR_RENDERER | CVAR_FLOAT, "polygonOffset units for drawing shadow buffer" );
 idCVar r_shadowMapOccluderFacing( "r_shadowMapOccluderFacing", "2", CVAR_RENDERER | CVAR_INTEGER, "0 = front faces, 1 = back faces, 2 = twosided" );
+idCVar r_shadowMapRegularDepthBiasScale( "r_shadowMapRegularDepthBiasScale", "0.999", CVAR_RENDERER | CVAR_FLOAT, "shadowmap bias to fight shadow acne for point and spot lights" );
+idCVar r_shadowMapSunDepthBiasScale( "r_shadowMapSunDepthBiasScale", "0.999991", CVAR_RENDERER | CVAR_FLOAT, "shadowmap bias to fight shadow acne for cascaded shadow mapping with parallel lights" );
 // RB end
 
 const char* fileExten[3] = { "tga", "png", "jpg" };
diff --git a/neo/renderer/tr_backend_draw.cpp b/neo/renderer/tr_backend_draw.cpp
index 81a57ea8..83dccf30 100644
--- a/neo/renderer/tr_backend_draw.cpp
+++ b/neo/renderer/tr_backend_draw.cpp
@@ -1302,7 +1302,7 @@ static void RB_RenderInteractions( const drawSurf_t* surfList, const viewLight_t
 		screenCorrectionParm[0] = 1.0f / ( JITTER_SIZE * shadowMapSamples ) ;
 		screenCorrectionParm[1] = 1.0f / JITTER_SIZE;
 		screenCorrectionParm[2] = 1.0f / shadowMapResolutions[vLight->shadowLOD];
-		screenCorrectionParm[3] = shadowMapSamples;
+		screenCorrectionParm[3] = vLight->parallel ? r_shadowMapSunDepthBiasScale.GetFloat() : r_shadowMapRegularDepthBiasScale.GetFloat();
 		SetFragmentParm( RENDERPARM_SCREENCORRECTIONFACTOR, screenCorrectionParm ); // rpScreenCorrectionFactor
 		
 		float jitterTexScale[4];
diff --git a/neo/renderer/tr_local.h b/neo/renderer/tr_local.h
index 26c0d89d..01b7b5c2 100644
--- a/neo/renderer/tr_local.h
+++ b/neo/renderer/tr_local.h
@@ -1070,6 +1070,8 @@ extern idCVar r_shadowMapLodBias;
 extern idCVar r_shadowMapPolygonFactor;
 extern idCVar r_shadowMapPolygonOffset;
 extern idCVar r_shadowMapOccluderFacing;
+extern idCVar r_shadowMapRegularDepthBiasScale;
+extern idCVar r_shadowMapSunDepthBiasScale;
 // RB end
 
 /*