Fixed environment sampling issue

.vscode/launch.json

@@ -125,6 +125,31 @@
                 }
             ]
         },
+        {
+            "name": "SpectralTest",
+            "type": "cppdbg",
+            "request": "launch",
+            "program": "${command:cmake.buildDirectory}/bin/pearray",
+            "args": [
+                "-i",
+                "${workspaceFolder}/examples/spectral_test.prc",
+                "-v",
+                "-p"
+            ],
+            "stopAtEntry": false,
+            "cwd": "${workspaceFolder}/build",
+            "environment": [],
+            "externalConsole": false,
+            "MIMode": "gdb",
+            "targetArchitecture": "x64",
+            "setupCommands": [
+                {
+                    "description": "Automatische Strukturierung und Einrückung für \"gdb\" aktivieren",
+                    "text": "-enable-pretty-printing",
+                    "ignoreFailures": true
+                }
+            ]
+        },
         {
             "name": "CornellBox-Water",
             "type": "cppdbg",

examples/spectral_test.prc

@@ -8,9 +8,9 @@
 	; Settings
 	(integrator
 		:type 'DIRECT'
-		:max_ray_depth 2
+		:max_ray_depth 1
 		:light_sampe_count 1
-		:msi true
+		:msi false
 	)
 	(sampler
 		:slot 'aa'

src/base/math/Tangent.h

@@ -56,7 +56,7 @@ inline void frame_duff(const Vector3f& N, Vector3f& Nx, Vector3f& Ny)
 	Ny				 = Vector3f(b, sign + N(1) * N(1) * a, -N(1));
 }
 
-inline void frame(const Vector3f& N, Vector3f& Nx, Vector3f& Ny)
+inline void unnormalized_frame(const Vector3f& N, Vector3f& Nx, Vector3f& Ny)
 {
 #ifdef PR_USE_ORTHOGONAL_FRAME_FRISVAD
 	return frame_frisvad(N, Nx, Ny);
@@ -65,6 +65,13 @@ inline void frame(const Vector3f& N, Vector3f& Nx, Vector3f& Ny)
 #endif
 }
 
+inline void frame(const Vector3f& N, Vector3f& Nx, Vector3f& Ny)
+{
+	unnormalized_frame(N, Nx, Ny);
+	Nx.normalize();
+	Ny.normalize();
+}
+
 inline void invert_frame(Vector3f& N, Vector3f& Nx, Vector3f& Ny)
 {
 	N = -N;

src/base/math/Transform.h

@@ -21,6 +21,7 @@ inline Vector3f safePosition(const Vector3f& pos,
 		offset = -offset;
 	Vector3f posOff = pos + offset;
 
+	PR_OPT_LOOP
 	for (int i = 0; i < 3; ++i) {
 		if (offset[i] > 0)
 			posOff[i] = nextFloatUp(posOff[i]);

src/plugins/main/entities/cone.cpp

@@ -181,11 +181,8 @@ class ConeEntity : public IEntity {
 			}
 		}
 
-		Tangent::frame(pt.N, pt.Nx, pt.Ny);
-
 		pt.N.normalize();
-		pt.Nx.normalize();
-		pt.Ny.normalize();
+		Tangent::frame(pt.N, pt.Nx, pt.Ny);
 
 		pt.EntityID	   = id();
 		pt.PrimitiveID = query.PrimitiveID;

src/plugins/main/entities/disk.cpp

@@ -97,14 +97,9 @@ class DiskEntity : public IEntity {
 	{
 		PR_PROFILE_THIS;
 
-		pt.N = normalMatrix() * mDisk.normal();
-
+		pt.N = (normalMatrix() * mDisk.normal()).normalized();
 		Tangent::frame(pt.N, pt.Nx, pt.Ny);
 
-		pt.N.normalize();
-		pt.Nx.normalize();
-		pt.Ny.normalize();
-
 		pt.UV		   = query.UV;
 		pt.EntityID	   = id();
 		pt.PrimitiveID = 0;

src/plugins/main/entities/mesh.cpp

@@ -175,7 +175,7 @@ class MeshEntity : public IEntity {
 		Face face = mMesh->base()->getFace(query.PrimitiveID);
 		pt.N	  = face.interpolateNormals(query.UV);
 
-		Tangent::frame(pt.N, pt.Nx, pt.Ny);
+		Tangent::unnormalized_frame(pt.N, pt.Nx, pt.Ny);
 		pt.UV = query.UV;
 
 		pt.MaterialID = face.MaterialSlot < mMaterials.size() ? mMaterials.at(face.MaterialSlot) : PR_INVALID_ID;

src/plugins/main/entities/quadric.cpp

@@ -143,9 +143,6 @@ class QuadricEntity : public IEntity {
 
 		Tangent::frame(pt.N, pt.Nx, pt.Ny);
 
-		pt.Nx.normalize();
-		pt.Ny.normalize();
-
 		pt.UVW = parameter.cwiseAbs();
 		if (pt.UVW(2) < PR_EPSILON) {
 			pt.UVW(0) /= pt.UVW(2);

src/plugins/main/entities/sphere.cpp

@@ -142,6 +142,7 @@ class SphereEntity : public IEntity {
 		pt.N.normalize();
 
 		Tangent::frame(pt.N, pt.Nx, pt.Ny);
+
 		const Vector2f uv = Spherical::uv_from_normal(pt.N);
 		pt.UV			  = uv;
 		pt.EntityID		  = id();

src/plugins/main/infinitelights/environment.cpp

@@ -38,9 +38,7 @@ class EnvironmentLight : public IInfiniteLight {
 			  const RenderTileSession&) const override
 	{
 		ShadingContext ctx;
-		Vector3f dir = mInvTransform * in.Ray.Direction;
-
-		ctx.UV			 = Spherical::uv_from_normal(dir);
+		ctx.UV			 = Spherical::uv_from_normal(mInvTransform * in.Ray.Direction);
 		ctx.WavelengthNM = in.Ray.WavelengthNM;
 
 		if constexpr (UseSplit) {
@@ -58,7 +56,7 @@ class EnvironmentLight : public IInfiniteLight {
 			const float denom	 = 2 * PR_PI * PR_PI * sinTheta;
 			out.PDF_S *= (denom <= PR_EPSILON) ? 0.0f : 1.0f / denom;
 		} else {
-			out.PDF_S = in.Point ? Sampling::cos_hemi_pdf(std::abs(in.Point->Surface.N.dot(dir))) : 1.0f;
+			out.PDF_S = in.Point ? Sampling::cos_hemi_pdf(std::abs(in.Point->Surface.N.dot(in.Ray.Direction))) : 1.0f;
 		}
 	}
 
@@ -68,16 +66,18 @@ class EnvironmentLight : public IInfiniteLight {
 		Vector2f uv;
 		if constexpr (UseDistribution) {
 			uv			 = mDistribution->sampleContinuous(in.RND, out.PDF_S);
-			out.Outgoing = Spherical::cartesian_from_uv(uv(0), uv(1));
+			out.Outgoing = mTransform * Spherical::cartesian_from_uv(uv(0), uv(1));
 
 			const float sinTheta = std::sin(uv(1) * PR_PI);
 			const float denom	 = 2 * PR_PI * PR_PI * sinTheta;
 			out.PDF_S *= (denom <= PR_EPSILON) ? 0.0f : 1 / denom;
 		} else {
 			uv			 = in.RND;
-			out.Outgoing = Sampling::cos_hemi(in.RND[0], in.RND[1], out.PDF_S);
+			out.Outgoing = Sampling::cos_hemi(in.RND[0], in.RND[1]);
+			out.PDF_S	 = Sampling::cos_hemi_pdf(out.Outgoing(2));
 		}
-		out.Outgoing = mTransform * Tangent::fromTangentSpace(in.Point.Surface.N, in.Point.Surface.Nx, in.Point.Surface.Ny, out.Outgoing);
+
+		out.Outgoing = Tangent::fromTangentSpace(in.Point.Surface.N, in.Point.Surface.Nx, in.Point.Surface.Ny, out.Outgoing);
 
 		ShadingContext coord;
 		coord.UV		   = uv;
@@ -93,11 +93,10 @@ class EnvironmentLight : public IInfiniteLight {
 			   << "  <EnvironmentLight>:" << std::endl
 			   << "    Radiance:     " << (mRadiance ? mRadiance->dumpInformation() : "NONE") << std::endl
 			   << "    Background:   " << (mBackground ? mBackground->dumpInformation() : "NONE") << std::endl;
-		if (mDistribution) {
+		if (mDistribution)
 			stream << "    Distribution: " << mDistribution->width() << "x" << mDistribution->height() << std::endl;
-		} else {
+		else
 			stream << "    Distribution: NONE" << std::endl;
-		};
 
 		return stream.str();
 	}

src/plugins/main/materials/lambert.cpp

@@ -40,8 +40,8 @@ class LambertMaterial : public IMaterial {
 		out.L = Sampling::cos_hemi(in.RND[0], in.RND[1]);
 
 		out.Weight = mAlbedo->eval(in.ShadingContext) * out.L(2) * PR_INV_PI;
-		out.Type   = MST_DiffuseReflection;
 		out.PDF_S  = Sampling::cos_hemi_pdf(out.L(2));
+		out.Type   = MST_DiffuseReflection;
 	}
 
 	std::string dumpInformation() const override

src/tests/tangent.cpp

@@ -9,7 +9,7 @@ PR_TEST("Frame 1")
 	auto N = Vector3f(0, 0, 1);
 
 	Vector3f Nx, Ny;
-	Tangent::frame(N, Nx, Ny);
+	Tangent::unnormalized_frame(N, Nx, Ny);
 
 	PR_CHECK_NEARLY_EQ(Nx, Vector3f(1, 0, 0));
 	PR_CHECK_NEARLY_EQ(Ny, Vector3f(0, 1, 0));
@@ -19,7 +19,7 @@ PR_TEST("Frame 2")
 	auto N = Vector3f(0, 1, 0);
 
 	Vector3f Nx, Ny;
-	Tangent::frame(N, Nx, Ny);
+	Tangent::unnormalized_frame(N, Nx, Ny);
 
 	PR_CHECK_NEARLY_EQ(Nx, Vector3f(1, 0, 0));
 	PR_CHECK_NEARLY_EQ(Ny, Vector3f(0, 0, -1));
@@ -29,7 +29,7 @@ PR_TEST("Frame Perpendicular")
 	auto N = Vector3f(0, 1, 0);
 
 	Vector3f Nx, Ny;
-	Tangent::frame(N, Nx, Ny);
+	Tangent::unnormalized_frame(N, Nx, Ny);
 
 	PR_CHECK_NEARLY_EQ(Nx.dot(N), 0);
 	PR_CHECK_NEARLY_EQ(Ny.dot(N), 0);
@@ -168,7 +168,7 @@ PR_TEST("Space Reversibility 2")
 {
 	auto N  = Vector3f(1, 1, 0).normalized();
 	Vector3f Nx, Ny;
-	Tangent::frame(N, Nx, Ny);
+	Tangent::unnormalized_frame(N, Nx, Ny);
 
 	auto V  = Vector3f(0, 1, 0);
 
@@ -195,7 +195,7 @@ PR_TEST("Space Reversibility 4")
 {
 	auto N  = Vector3f(1, 1, 0).normalized();
 	Vector3f Nx, Ny;
-	Tangent::frame(N, Nx, Ny);
+	Tangent::unnormalized_frame(N, Nx, Ny);
 
 	auto V  = Vector3f(0, 1, 0);