Improved shadow mapping performance using the shadow LOD and tweaked

polygon offsets to fight shadow acne

base/renderprogs/interactionSM.pixel

@@ -185,13 +185,13 @@ void main( PS_IN fragment, out PS_OUT result )
 	shadowTexcoord.z = dot4( modelPosition, shadowMatrixZ );
 	shadowTexcoord.w = dot4( modelPosition, shadowMatrixW );
 	
-	//float bias = 0.001 * tan( acos( ldotN ) );
+	//float bias = 0.005 * tan( acos( ldotN ) );
-	//bias = clamp( bias, 0, 0.001 );
+	//bias = clamp( bias, 0, 0.01 );
 	float bias = 0.001;
 	
 	shadowTexcoord.xyz /= shadowTexcoord.w;
-	shadowTexcoord.z = shadowTexcoord.z * 0.9991;
+	//shadowTexcoord.z = shadowTexcoord.z * 0.9991;
-	//shadowTexcoord.z = shadowTexcoord.z - bias;
+	shadowTexcoord.z = shadowTexcoord.z - bias;
 	shadowTexcoord.w = float(shadowIndex);
 
 #if 0

neo/renderer/Framebuffer.cpp

@@ -77,9 +77,14 @@ void Framebuffer::Init()
 	int width, height;
 	width = height = r_shadowMapImageSize.GetInteger();
 	
-	globalFramebuffers.shadowFBO = new Framebuffer( "_shadowMap" , width, height );
+	for( int i = 0; i < MAX_SHADOWMAP_RESOLUTIONS; i++ )
-	globalFramebuffers.shadowFBO->Bind();
+	{
-	glDrawBuffers( 0, NULL );
+		width = height = shadowMapResolutions[i];
+		
+		globalFramebuffers.shadowFBO[i] = new Framebuffer( "_shadowMap" , width, height );
+		globalFramebuffers.shadowFBO[i]->Bind();
+		glDrawBuffers( 0, NULL );
+	}
 //	globalFramebuffers.shadowFBO->AddColorBuffer( GL_RGBA8, 0 );
 //	globalFramebuffers.shadowFBO->AddDepthBuffer( GL_DEPTH_COMPONENT24 );
 //	globalFramebuffers.shadowFBO->Check();

neo/renderer/Framebuffer.h

@@ -29,6 +29,13 @@ If you have questions concerning this license or the applicable additional terms
 #ifndef __FRAMEBUFFER_H__
 #define __FRAMEBUFFER_H__
 
+static const int MAX_SHADOWMAP_RESOLUTIONS = 5;
+#if 1
+static	int shadowMapResolutions[MAX_SHADOWMAP_RESOLUTIONS] = { 2048, 1024, 512, 512, 256 };
+#else
+static	int shadowMapResolutions[MAX_SHADOWMAP_RESOLUTIONS] = { 1024, 1024, 1024, 1024, 1024 };
+#endif
+
 class Framebuffer
 {
 public:
@@ -82,7 +89,7 @@ private:
 
 struct globalFramebuffers_t
 {
-	Framebuffer*				shadowFBO;
+	Framebuffer*				shadowFBO[MAX_SHADOWMAP_RESOLUTIONS];
 };
 extern globalFramebuffers_t globalFramebuffers;
 

neo/renderer/Image.h

@@ -337,7 +337,7 @@ public:
 	idImage* 			fogImage;					// increasing alpha is denser fog
 	idImage* 			fogEnterImage;				// adjust fogImage alpha based on terminator plane
 	// RB begin
-	idImage*			shadowImage;
+	idImage*			shadowImage[5];
 	idImage*			jitterImage1;				// shadow jitter
 	idImage*			jitterImage4;
 	idImage*			jitterImage16;

neo/renderer/Image_intrinsic.cpp

@@ -451,9 +451,33 @@ void R_QuadraticImage( idImage* image )
 }
 
 // RB begin
-static void R_CreateShadowMapImage( idImage* image )
+static void R_CreateShadowMapImage_Res0( idImage* image )
 {
-	int size = r_shadowMapImageSize.GetInteger();
+	int size = shadowMapResolutions[0];
+	image->GenerateShadowArray( size, size, TF_LINEAR, TR_CLAMP_TO_ZERO_ALPHA, TD_SHADOW_ARRAY );
+}
+
+static void R_CreateShadowMapImage_Res1( idImage* image )
+{
+	int size = shadowMapResolutions[1];
+	image->GenerateShadowArray( size, size, TF_LINEAR, TR_CLAMP_TO_ZERO_ALPHA, TD_SHADOW_ARRAY );
+}
+
+static void R_CreateShadowMapImage_Res2( idImage* image )
+{
+	int size = shadowMapResolutions[2];
+	image->GenerateShadowArray( size, size, TF_LINEAR, TR_CLAMP_TO_ZERO_ALPHA, TD_SHADOW_ARRAY );
+}
+
+static void R_CreateShadowMapImage_Res3( idImage* image )
+{
+	int size = shadowMapResolutions[3];
+	image->GenerateShadowArray( size, size, TF_LINEAR, TR_CLAMP_TO_ZERO_ALPHA, TD_SHADOW_ARRAY );
+}
+
+static void R_CreateShadowMapImage_Res4( idImage* image )
+{
+	int size = shadowMapResolutions[4];
 	image->GenerateShadowArray( size, size, TF_LINEAR, TR_CLAMP_TO_ZERO_ALPHA, TD_SHADOW_ARRAY );
 }
 
@@ -562,7 +586,11 @@ void idImageManager::CreateIntrinsicImages()
 	ImageFromFunction( "_quadratic", R_QuadraticImage );
 	
 	// RB begin
-	shadowImage = ImageFromFunction( va( "_shadowMap%i_0", r_shadowMapImageSize.GetInteger() ), R_CreateShadowMapImage );
+	shadowImage[0] = ImageFromFunction( va( "_shadowMapArray%i", shadowMapResolutions[0] ), R_CreateShadowMapImage_Res0 );
+	shadowImage[1] = ImageFromFunction( va( "_shadowMapArray%i", shadowMapResolutions[1] ), R_CreateShadowMapImage_Res1 );
+	shadowImage[2] = ImageFromFunction( va( "_shadowMapArray%i", shadowMapResolutions[2] ), R_CreateShadowMapImage_Res2 );
+	shadowImage[3] = ImageFromFunction( va( "_shadowMapArray%i", shadowMapResolutions[3] ), R_CreateShadowMapImage_Res3 );
+	shadowImage[4] = ImageFromFunction( va( "_shadowMapArray%i", shadowMapResolutions[4] ), R_CreateShadowMapImage_Res4 );
 	
 	jitterImage1 = globalImages->ImageFromFunction( "_jitter1", R_CreateJitterImage1 );
 	jitterImage4 = globalImages->ImageFromFunction( "_jitter4", R_CreateJitterImage4 );

neo/renderer/RenderSystem_init.cpp

@@ -222,8 +222,11 @@ idCVar r_shadowMapBiasScale( "r_shadowMapBiasScale", "0.0001", CVAR_RENDERER | C
 idCVar r_shadowMapSamples( "r_shadowMapSamples", "16", CVAR_RENDERER | CVAR_INTEGER, "0, 1, 4, or 16" );
 idCVar r_shadowMapSplits( "r_shadowMapSplits", "3", CVAR_RENDERER | CVAR_INTEGER, "number of splits for cascaded shadow mapping with parallel lights", 0, 4 );
 idCVar r_shadowMapSplitWeight( "r_shadowMapSplitWeight", "0.9", CVAR_RENDERER | CVAR_FLOAT, "" );
-idCVar r_shadowMapLodScale( "r_shadowMapLodScale", "0.8", CVAR_RENDERER | CVAR_FLOAT, "" );
+idCVar r_shadowMapLodScale( "r_shadowMapLodScale", "1.4", CVAR_RENDERER | CVAR_FLOAT, "" );
 idCVar r_shadowMapLodBias( "r_shadowMapLodBias", "0", CVAR_RENDERER | CVAR_INTEGER, "" );
+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" );
 // RB end
 
 

neo/renderer/tr_backend_draw.cpp

@@ -1346,7 +1346,7 @@ static void RB_RenderInteractions( const drawSurf_t* surfList, const viewLight_t
 		{
 			// texture 5 will be the shadow maps array
 			GL_SelectTexture( INTERACTION_TEXUNIT_SHADOWMAPS );
-			globalImages->shadowImage->Bind();
+			globalImages->shadowImage[vLight->shadowLOD]->Bind();
 			
 			// texture 6 will be the jitter texture for soft shadowing
 			GL_SelectTexture( INTERACTION_TEXUNIT_JITTER );
@@ -2237,18 +2237,28 @@ static void RB_ShadowMapPass( const drawSurf_t* drawSurfs, const viewLight_t* vL
 	
 	uint64 glState = 0;
 	
-	//GL_PolygonOffset( r_shadowPolygonFactor.GetFloat(), -r_shadowPolygonOffset.GetFloat() );
-	
-	
 	// the actual stencil func will be set in the draw code, but we need to make sure it isn't
 	// disabled here, and that the value will get reset for the interactions without looking
 	// like a no-change-required
-	//GL_State( glState | GLS_POLYGON_OFFSET );
+	GL_State( glState | GLS_POLYGON_OFFSET );
 	
-	GL_State( GLS_DEFAULT );
+	switch( r_shadowMapOccluderFacing.GetInteger() )
-	
+	{
-	// Two Sided Stencil reduces two draw calls to one for slightly faster shadows
+		case 0:
-	GL_Cull( CT_TWO_SIDED );
+			GL_Cull( CT_FRONT_SIDED );
+			GL_PolygonOffset( r_shadowMapPolygonFactor.GetFloat(), r_shadowMapPolygonOffset.GetFloat() );
+			break;
+			
+		case 1:
+			GL_Cull( CT_BACK_SIDED );
+			GL_PolygonOffset( -r_shadowMapPolygonFactor.GetFloat(), -r_shadowMapPolygonOffset.GetFloat() );
+			break;
+			
+		default:
+			GL_Cull( CT_TWO_SIDED );
+			GL_PolygonOffset( r_shadowMapPolygonFactor.GetFloat(), r_shadowMapPolygonOffset.GetFloat() );
+			break;
+	}
 	
 	idRenderMatrix lightProjectionRenderMatrix;
 	idRenderMatrix lightViewRenderMatrix;
@@ -2546,20 +2556,20 @@ static void RB_ShadowMapPass( const drawSurf_t* drawSurfs, const viewLight_t* vL
 	
 	
 	
-	globalFramebuffers.shadowFBO->Bind();
+	globalFramebuffers.shadowFBO[vLight->shadowLOD]->Bind();
 	
 	if( side < 0 )
 	{
-		globalFramebuffers.shadowFBO->AttachImageDepthLayer( globalImages->shadowImage, 0 );
+		globalFramebuffers.shadowFBO[vLight->shadowLOD]->AttachImageDepthLayer( globalImages->shadowImage[vLight->shadowLOD], 0 );
 	}
 	else
 	{
-		globalFramebuffers.shadowFBO->AttachImageDepthLayer( globalImages->shadowImage, side );
+		globalFramebuffers.shadowFBO[vLight->shadowLOD]->AttachImageDepthLayer( globalImages->shadowImage[vLight->shadowLOD], side );
 	}
 	
-	globalFramebuffers.shadowFBO->Check();
+	globalFramebuffers.shadowFBO[vLight->shadowLOD]->Check();
 	
-	GL_ViewportAndScissor( 0, 0, r_shadowMapImageSize.GetInteger(), r_shadowMapImageSize.GetInteger() );
+	GL_ViewportAndScissor( 0, 0, shadowMapResolutions[vLight->shadowLOD], shadowMapResolutions[vLight->shadowLOD] );
 	
 	glClear( GL_DEPTH_BUFFER_BIT );
 	

neo/renderer/tr_backend_rendertools.cpp

@@ -1888,20 +1888,11 @@ static void RB_ShowShadowMapLODs()
 	int count = 0;
 	for( viewLight_t* vLight = backEnd.viewDef->viewLights; vLight != NULL; vLight = vLight->next )
 	{
-#if 0
+		if( !vLight->lightDef->LightCastsShadows() )
-		const idMaterial* lightShader = vLight->lightShader;
-		
-		if( lightShader->IsFogLight() )
 		{
 			continue;
 		}
 		
-		if( lightShader->IsBlendLight() )
-		{
-			continue;
-		}
-#endif
-		
 		count++;
 		
 		// depth buffered planes
@@ -2925,7 +2916,7 @@ void RB_ShowShadowMaps()
 	if( !r_showShadowMaps.GetBool() )
 		return;
 		
-	image = globalImages->shadowImage;
+	image = globalImages->shadowImage[0];
 	if( !image )
 	{
 		return;

neo/renderer/tr_frontend_addlights.cpp

@@ -266,7 +266,7 @@ static void R_AddSingleLight( viewLight_t* vLight )
 		vLight->scissorRect.zmax = projected[1][2];
 		
 		// RB: calculate shadow LOD similar to Q3A .md3 LOD code
-		vLight->shadowLOD = -1;
+		vLight->shadowLOD = 0;
 		
 		if( r_useShadowMapping.GetBool() && lightCastsShadows )
 		{
@@ -275,7 +275,7 @@ static void R_AddSingleLight( viewLight_t* vLight )
 			int             lod;
 			int             numLods;
 			
-			numLods = 5;
+			numLods = MAX_SHADOWMAP_RESOLUTIONS;
 			
 			// compute projected bounding sphere
 			// and use that as a criteria for selecting LOD
@@ -323,15 +323,17 @@ static void R_AddSingleLight( viewLight_t* vLight )
 			if( lod >= numLods )
 			{
 				// don't draw any shadow
-				lod = -1;
+				//lod = -1;
 				
-				//lod = numLods - 1;
+				lod = numLods - 1;
 			}
 			
 			// never give ultra quality for point lights
 			if( lod == 0 && light->parms.pointLight )
+			{
 				lod = 1;
-				
+			}
+			
 			vLight->shadowLOD = lod;
 		}
 		// RB end

neo/renderer/tr_local.h

@@ -1065,6 +1065,9 @@ extern idCVar r_shadowMapSplits;
 extern idCVar r_shadowMapSplitWeight;
 extern idCVar r_shadowMapLodScale;
 extern idCVar r_shadowMapLodBias;
+extern idCVar r_shadowMapPolygonFactor;
+extern idCVar r_shadowMapPolygonOffset;
+extern idCVar r_shadowMapOccluderFacing;
 // RB end
 
 /*