raytracing: improved additive blending support

WickedEngine/shaders/raytraceCS.hlsl

@@ -54,6 +54,13 @@ void main(uint3 DTid : SV_DispatchThreadID, uint groupIndex : SV_GroupIndex)
 	{
 		ray.Direction = normalize(ray.Direction);
 
+		float4 additive_dist = float4(0, 0, 0, FLT_MAX);
+
+#ifdef RTAPI
+		RayQuery<
+			RAY_FLAG_SKIP_PROCEDURAL_PRIMITIVES
+		> q;
+
 		uint flags = 0;
 #ifdef RAY_BACKFACE_CULLING
 		flags |= RAY_FLAG_CULL_BACK_FACING_TRIANGLES;
@@ -63,13 +70,9 @@ void main(uint3 DTid : SV_DispatchThreadID, uint groupIndex : SV_GroupIndex)
 			flags |= RAY_FLAG_FORCE_OPAQUE;
 		}
 
-#ifdef RTAPI
-		RayQuery<
-			RAY_FLAG_SKIP_PROCEDURAL_PRIMITIVES
-		> q;
 		q.TraceRayInline(
 			scene_acceleration_structure,	// RaytracingAccelerationStructure AccelerationStructure
-			flags,								// uint RayFlags
+			flags,							// uint RayFlags
 			xTraceUserData.y,				// uint InstanceInclusionMask
 			ray								// RayDesc Ray
 		);
@@ -88,12 +91,22 @@ void main(uint3 DTid : SV_DispatchThreadID, uint groupIndex : SV_GroupIndex)
 			if (!surface.load(prim, q.CandidateTriangleBarycentrics()))
 				break;
 
-			[branch]
-			if (surface.opacity - rng.next_float() >= 0)
+			if (surface.material.options & SHADERMATERIAL_OPTION_BIT_ADDITIVE)
+			{
+				additive_dist.xyz += max(0, energy * surface.emissiveColor);
+				additive_dist.w = min(additive_dist.w, q.CandidateTriangleRayT());
+			}
+			else if (surface.opacity - rng.next_float() >= 0)
 			{
 				q.CommitNonOpaqueTriangleHit();
 			}
 		}
+
+		if (additive_dist.w <= q.CommittedRayT())
+		{
+			result += max(0, energy * additive_dist.xyz);
+		}
+
 		if (q.CommittedStatus() != COMMITTED_TRIANGLE_HIT)
 #else
 		RayHit hit = TraceRay_Closest(ray, xTraceUserData.y, rng, groupIndex);
@@ -159,6 +172,8 @@ void main(uint3 DTid : SV_DispatchThreadID, uint groupIndex : SV_GroupIndex)
 		surface.V = -ray.Direction;
 		surface.update();
 
+		result += max(0, energy * surface.emissiveColor);
+
 		raycone = raycone.propagate(surface.roughnessBRDF, surface.hit_depth);
 
 		if (bounce == 0)
@@ -173,8 +188,6 @@ void main(uint3 DTid : SV_DispatchThreadID, uint groupIndex : SV_GroupIndex)
 			break;
 		}
 
-		result += max(0, energy * surface.emissiveColor);
-
 		if (!surface.material.IsUnlit())
 		{
 			// Light sampling:

WickedEngine/shaders/rtreflectionCS.hlsl

@@ -93,6 +93,8 @@ void main(uint2 DTid : SV_DispatchThreadID)
 	RayCone raycone = RayCone::from_spread_angle(pixel_cone_spread_angle_from_image_height(postprocess.resolution.y));
 	raycone = raycone.propagate(sqr(max(minraycone, roughness)), lineardepth * GetCamera().z_far);
 
+	float4 additive_dist = float4(0, 0, 0, FLT_MAX);
+
 	RayQuery<
 		RAY_FLAG_SKIP_PROCEDURAL_PRIMITIVES
 	> q;
@@ -119,12 +121,22 @@ void main(uint2 DTid : SV_DispatchThreadID)
 
 		float alphatest = clamp(blue_noise(DTid.xy, q.CandidateTriangleRayT()).r, 0, 0.99);
 
-		[branch]
-		if (surface.opacity - alphatest >= 0)
+		if (surface.material.options & SHADERMATERIAL_OPTION_BIT_ADDITIVE)
+		{
+			additive_dist.xyz += max(0, surface.emissiveColor);
+			additive_dist.w = min(additive_dist.w, q.CandidateTriangleRayT());
+		}
+		else if (surface.opacity - alphatest >= 0)
 		{
 			q.CommitNonOpaqueTriangleHit();
 		}
 	}
+
+	if (additive_dist.w <= q.CommittedRayT())
+	{
+		payload.data.xyz += max(0, additive_dist.xyz);
+	}
+
 	if (q.CommittedStatus() != COMMITTED_TRIANGLE_HIT)
 	{
 		// miss:
@@ -209,7 +221,9 @@ void main(uint2 DTid : SV_DispatchThreadID)
 				lighting.indirect.diffuse = ddgi_sample_irradiance(surface.P, surface.N);
 			}
 
-			ApplyLighting(surface, lighting, payload.data);
+			float4 color = 0;
+			ApplyLighting(surface, lighting, color);
+			payload.data.xyz += color.rgb;
 		}
 		payload.data.w = q.CommittedRayT();
 	}

WickedEngine/wiScene.cpp

@@ -3798,6 +3798,8 @@ namespace wi::scene
 					inst.uid = entity;
 					inst.layerMask = hair.layerMask;
 					inst.geometryOffset = (uint)geometryAllocation;
+					inst.emissive = wi::math::Pack_R11G11B10_FLOAT(XMFLOAT3(1, 1, 1));
+					inst.color = wi::math::CompressColor(XMFLOAT4(1, 1, 1, 1));
 
 					const size_t instanceIndex = objects.GetCount() + args.jobIndex;
 					std::memcpy(instanceArrayMapped + instanceIndex, &inst, sizeof(inst));
@@ -3878,6 +3880,8 @@ namespace wi::scene
 			inst.uid = entity;
 			inst.layerMask = emitter.layerMask;
 			inst.geometryOffset = (uint)geometryAllocation;
+			inst.emissive = wi::math::Pack_R11G11B10_FLOAT(XMFLOAT3(1, 1, 1));
+			inst.color = wi::math::CompressColor(XMFLOAT4(1, 1, 1, 1));
 
 			const size_t instanceIndex = objects.GetCount() + hairs.GetCount() + args.jobIndex;
 			std::memcpy(instanceArrayMapped + instanceIndex, &inst, sizeof(inst));

WickedEngine/wiVersion.cpp

@@ -9,7 +9,7 @@ namespace wi::version
 	// minor features, major updates, breaking compatibility changes
 	const int minor = 60;
 	// minor bug fixes, alterations, refactors, updates
-	const int revision = 38;
+	const int revision = 39;
 
 	const std::string version_string = std::to_string(major) + "." + std::to_string(minor) + "." + std::to_string(revision);