area light improvements

WickedEngine/shaders/lightCullingCS.hlsl

@@ -272,7 +272,7 @@ void main(uint3 Gid : SV_GroupID, uint3 DTid : SV_DispatchThreadID, uint3 GTid :
 		if (entity.IsStaticLight())
 			continue; // static lights will be skipped here (they are used at lightmap baking)
 		float3 positionVS = mul(GetCamera().view, float4(entity.position, 1)).xyz;
-		Sphere sphere = { positionVS.xyz, entity.GetRange() };
+		Sphere sphere = { positionVS.xyz, max(entity.GetLength(), entity.GetHeight()) + entity.GetRange() };
 		if (SphereInsideFrustum(sphere, GroupFrustum, nearClipVS, maxDepthVS))
 		{
 			AppendEntity_Transparent(i);

WickedEngine/shaders/lightingHF.hlsli

@@ -425,6 +425,7 @@ inline void light_rect(in ShaderEntity light, in Surface surface, inout Lighting
 	const half3 forward = cross(up, right);
 	const half light_length = max(0.01, light.GetLength());
 	const half light_height = max(0.01, light.GetHeight());
+	const half light_area = light_length * light_height;
 	const float3 p0 = light.position - right * light_length * 0.5 + up * light_height * 0.5;
 	const float3 p1 = light.position + right * light_length * 0.5 + up * light_height * 0.5;
 	const float3 p2 = light.position + right * light_length * 0.5 - up * light_height * 0.5;
@@ -432,8 +433,15 @@ inline void light_rect(in ShaderEntity light, in Surface surface, inout Lighting
 	
 	if (dot(surface.P - light.position, forward) <= 0)
 		return; // behind light
+
+	// Determine closest point on rectangle to surface position:
+	float3 closest_point_on_plane_to_surface = point_on_plane(surface.P, light.position, forward);
+	float3 closest_vector_on_plane = closest_point_on_plane_to_surface - light.position;
+	float2 plane_point = float2(dot(closest_vector_on_plane, right), dot(closest_vector_on_plane, up));
+	float2 nearest_point = float2(clamp(plane_point.x, -light_length * 0.5, light_length * 0.5), clamp(plane_point.y, -light_height * 0.5, light_height * 0.5));
+	float3 rectangle_point = light.position + nearest_point.x * right + nearest_point.y * up;
 		
-	float3 Lunnormalized = light.position - surface.P;
+	float3 Lunnormalized = rectangle_point - surface.P;
 
 	const half dist2 = dot(Lunnormalized, Lunnormalized);
 	const half range = light.GetRange();
@@ -449,6 +457,7 @@ inline void light_rect(in ShaderEntity light, in Surface surface, inout Lighting
 	surface_to_light.create(surface, L);
 	
 	// Solid angle based on the Frostbite presentation: Moving Frostbite to Physically Based Rendering by Sebastien Lagarde, Charles de Rousiers, Siggraph 2014
+	//	https://media.contentapi.ea.com/content/dam/eacom/frostbite/files/course-notes-moving-frostbite-to-pbr-v2.pdf
 	float3 v0 = normalize(p0 - surface.P);
 	float3 v1 = normalize(p1 - surface.P);
 	float3 v2 = normalize(p2 - surface.P);
@@ -501,9 +510,9 @@ inline void light_rect(in ShaderEntity light, in Surface surface, inout Lighting
 			return; // light color lost after shadow
 	}
 		
-	light_color *= attenuation_pointlight(dist2, range, range2);
+	light_color *= attenuation_pointlight(dist2, range, range2); // dist2 is the closest point on rectangle, so it will not be a falloff from light center, but as if a point light is placed on the closest rectangle point
 	
-	half3 light_color_diffuse = light_color;
+	half3 light_color_diffuse = light_color * light_area * PI; // I increase the light color by the surface area, because I want larger lights to illuminate more.
 	
 	half3 light_color_specular = light_color;
 

WickedEngine/shaders/objectHF.hlsli

@@ -545,6 +545,7 @@ float4 main(PixelInput input, in bool is_frontface : SV_IsFrontFace APPEND_COVER
 		input.nor = -input.nor;
 	}
 	surface.N = normalize(input.nor);
+	surface.facenormal = surface.N;
 #endif // OBJECTSHADER_USE_NORMAL
 
 #ifdef OBJECTSHADER_USE_COMMON

WickedEngine/shaders/vRectLightPS.hlsl

@@ -2,7 +2,7 @@
 
 float4 main(float4 pos : SV_Position, float2 uv : TEXCOORD) : SV_TARGET
 {
-	float4 color = float4(xLightColor.rgb * xLightEnerdis.x / (2 * PI), 1); // 2*PI: balance the displaying of light visualizer with the diffuse strength of lighting.
+	float4 color = float4(xLightColor.rgb * xLightEnerdis.x, 1);
 
 	int maskTexDescriptor = (int)xLightEnerdis.y;
 	if (maskTexDescriptor >= 0)

WickedEngine/wiVersion.cpp

@@ -9,7 +9,7 @@ namespace wi::version
 	// minor features, major updates, breaking compatibility changes
 	const int minor = 71;
 	// minor bug fixes, alterations, refactors, updates
-	const int revision = 772;
+	const int revision = 773;
 
 	const std::string version_string = std::to_string(major) + "." + std::to_string(minor) + "." + std::to_string(revision);