Fix volume+surface scene rendering, fix transform issues for light & …

…volume sampling, other fixes (#44) * fix transform scaling in direct light sampling * fix nextRayQueue should use current wavefront depth * render to screen in RGBA8 * fix surface do not have medium inside a medium * update banner
cuteday · Nov 9, 2023 · 9068f5b · 9068f5b
1 parent 75762e6
commit 9068f5b
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Showing 28 changed files with 175 additions and 121 deletions.
diff --git a/common/configs/example_smoke.json b/common/configs/example_smoke.json
@@ -1,7 +1,5 @@
 {
-    "environment": "$sky.exr",
-    "model": "common/assets/scenes/smoke/smoke.vdb",
-    "passes": [
+   "passes": [
         {
             "enable": true,
             "name": "WavefrontPathTracer",
@@ -24,7 +22,7 @@
             "enable": true,
             "name": "ToneMappingPass",
 			"params": {
-				"exposure": 0.5,
+				"exposure": 2,
 				"operator": "aces"
 			}
         }
@@ -34,6 +32,18 @@
         750
     ],
     "scene": {
+        "model": [
+            {
+                "model": "common/assets/scenes/smoke/smoke.vdb",
+                "name": "Smoke",
+                "params": {
+                    "g": 0,
+                    "sigma_a": [1, 0.5, 0.8],
+                    "sigma_s": [0.8, 0.9, 0.8]
+                }
+            }
+        ],
+        "environment": "$sky.exr",
         "camera": {
             "mData": {
                 "aspectRatio": 1.093298316001892,

diff --git a/common/configs/example_volbox.json b/common/configs/example_volbox.json
@@ -1,14 +1,10 @@
 {
-	"resolution": [
-		750,
-		750
-	],
-	"passes": [
+    "passes": [
 		{
 			"enable": true,
 			"name": "WavefrontPathTracer",
 			"params": {
-				"nee": true,
+				"nee": false,
 				"rr": 0.8,
 				"max_depth": 10
 			}
@@ -29,55 +25,68 @@
 			"enable": true,
 			"name": "ToneMappingPass",
 			"params": {
-				"exposure": 1,
+				"exposure": 5,
 				"operator": "aces"
 			}
 		}
-	],
-	"scene": {
-		"model": [
-			{
-				"model": "common/assets/scenes/cbox/cbox.obj"
-			},
-			{
-				"model": "common/assets/scenes/smoke/smoke.vdb"
-			}
-		],
-		"camera": {
-			"mData": {
-				"aspectRatio": 1.0,
-				"focalDistance": 10.0,
-				"focalLength": 21.0,
-				"lensRadius": 0.0,
-				"pos": [
-					-0.010055910795927048,
-					1.0200917720794678,
-					2.828592300415039
-				],
-				"target": [
-					-0.011140584014356136,
-					1.0211291313171387,
-					-0.2837386131286621
-				],
-				"up": [
-					0.0,
-					1.0,
-					0.0
-				]
-			}
-		},
-		"cameraController": {
-			"mData": {
-				"pitch": 0.0003333091735839844,
-				"radius": 3.1123313903808594,
-				"target": [
-					-0.011140584014356136,
-					1.0211291313171387,
-					-0.2837386131286621
-				],
-				"yaw": 0.000348508358001709
-			}
-		}
-	},
-	"spp": 0
+    ],
+    "resolution": [
+        750,
+        750
+    ],
+    "scene": {
+        "camera": {
+            "mData": {
+                "aspectRatio": 1.0,
+                "focalDistance": 10.0,
+                "focalLength": 21.0,
+                "lensRadius": 0.0,
+                "pos": [
+                    -0.10795403271913528,
+                    40.9928092956543,
+                    111.58308410644531
+                ],
+                "target": [
+                    -0.14693589508533478,
+                    41.03009033203125,
+                    -0.27035611867904663
+                ],
+                "up": [
+                    0.0,
+                    1.0,
+                    0.0
+                ]
+            }
+        },
+        "cameraController": {
+            "mData": {
+                "pitch": 0.0003333091735839844,
+                "radius": 111.85345458984375,
+                "target": [
+                    -0.14693589508533478,
+                    41.03009033203125,
+                    -0.27035611867904663
+                ],
+                "yaw": 0.000348508358001709
+            }
+        },
+        "model": [
+            {
+                "model": "common/assets/scenes/cbox/cbox.obj",
+                "name": "Cornell Box",
+                "scale": [40, 40, 40]
+            },
+            {
+                "model": "common/assets/scenes/smoke/smoke.vdb",
+                "name": "Smoke",
+                "params": {
+                    "g": 0,
+                    "sigma_a": [1, 0.5, 0.8],
+                    "sigma_s": [0.8, 0.9, 0.8]
+                },
+                "scale": [1, 1, 1],
+                "translate": [0, 5, 0]
+            }
+        ]
+    }
 }
diff --git a/common/demo/kirara.jpg b/common/demo/kirara.jpg
diff --git a/common/demo/kirara.png b/common/demo/kirara.png
diff --git a/src/core/math/include/krrmath/array.h b/src/core/math/include/krrmath/array.h
@@ -49,6 +49,17 @@ class Array : public Eigen::Array<T, Size, 1> {
 		ss << "[" << *this << "]";
 		return std::regex_replace(ss.str(), std::regex("\n"), ", ");
 	}
+
+#ifdef KRR_MATH_JSON
+	friend void to_json(json &j, const Array<T, Size> &v) {
+		for (int i = 0; i < Size; i++) j.push_back(v[i]);
+	}
+
+	friend void from_json(const json &j, Array<T, Size> &v) {
+		assert(j.size() == Size);
+		for (int i = 0; i < Size; i++) v[i] = (T) j.at(i);
+	}
+#endif
 };
 
 template <typename T>

diff --git a/src/core/shape.h b/src/core/shape.h
@@ -28,9 +28,12 @@ class Triangle{
 
 	KRR_CALLABLE float area()const {
 		rt::MeshData *mesh = instance->mesh;
+		const Affine3f &transform = instance->transform;
 		Vector3i v = mesh->indices[primId];
-		Vector3f p0 = mesh->positions[v[0]], p1 = mesh->positions[v[1]],
-				 p2 = mesh->positions[v[2]];
+		/* Remember to transform the vertices, in case that the meshes are scaled */
+		Vector3f p0 = transform * mesh->positions[v[0]], 
+				 p1 = transform * mesh->positions[v[1]],
+				 p2 = transform * mesh->positions[v[2]];
 		float s = 0.5f * length(cross(p1 - p0, p2 - p0));
 		DCHECK(s > 0);
 		return s;
@@ -44,9 +47,8 @@ class Triangle{
 				 p1 = transform * mesh->positions[v[1]],
 				 p2 = transform * mesh->positions[v[2]];
 
-		return utils::sphericalTriangleArea(normalize(p0 - p), 
-			normalize(p1 - p),
-			normalize(p2 - p));
+		return utils::sphericalTriangleArea(normalize(p0 - p), normalize(p1 - p),
+											normalize(p2 - p));
 	}
 
 	KRR_CALLABLE ShapeSample sample(Vector2f u) const {
@@ -77,13 +79,13 @@ class Triangle{
 
 		// transform to world space [TODO: refactor]
 		p		= instance->getTransform() * p;
-		n		= instance->getTransposedInverseTransform() * n;
+		n		= (instance->getTransposedInverseTransform() * n).normalized();
 		ss.intr = Interaction(p, n, uvSample);
 		ss.pdf	= 1 / area();
 		return ss;
 	}
 
-	// TODO: Direct sampling on the projeced area to the sphere.
+	// TODO: Direct sampling on the projected area to the sphere.
 	KRR_CALLABLE ShapeSample sample(Vector2f u, const ShapeSampleContext &ctx) const {
 		// sample w.r.t. the reference point,
 		// also the pdf counted is in solid angle.

diff --git a/src/core/window.h b/src/core/window.h
@@ -31,7 +31,7 @@ struct DeviceCreationParameters {
 	uint32_t backBufferHeight		= 720;
 	uint32_t refreshRate			= 0;
 	uint32_t swapChainBufferCount	= 2;
-	nvrhi::Format swapChainFormat	= nvrhi::Format::SRGBA8_UNORM;
+	nvrhi::Format swapChainFormat	= nvrhi::Format::RGBA8_UNORM;	// not srgb, since we render in linear HDR.
 	nvrhi::Format renderFormat		= nvrhi::Format::RGBA32_FLOAT;
 	uint32_t swapChainSampleCount	= 1;
 	uint32_t swapChainSampleQuality = 0;

diff --git a/src/main/renderer.h b/src/main/renderer.h
@@ -42,7 +42,6 @@ class RenderApp : public DeviceManager{
 	void loadConfig(const json config);
 
 private:
-	int mSpp{ 0 };			// Samples needed tobe rendered, 0 means unlimited.
 	Scene::SharedPtr mScene;
 	UIRenderer::SharedPtr mpUIRenderer;
 	ProfilerUI::UniquePtr mProfilerUI;

diff --git a/src/misc/render/ppg/device.cu b/src/misc/render/ppg/device.cu
@@ -48,6 +48,7 @@ extern "C" __global__ void KRR_RT_CH(Closest)() {
 	RayWorkItem r = getRayWorkItem();
 	int pixelId				  = launchParams.currentRayQueue->pixelId[getRayId()];
 	SampledWavelengths lambda = launchParams.pixelState->lambda[pixelId];
+	intr.medium				  = r.ray.medium; // if this surface is inside a medium
 	prepareSurfaceInteraction(intr, hitInfo, lambda);
 	if (launchParams.mediumSampleQueue && r.ray.medium) {
 		launchParams.mediumSampleQueue->push(r, intr, optixGetRayTmax());

diff --git a/src/misc/render/ppg/integrator.cpp b/src/misc/render/ppg/integrator.cpp
@@ -182,7 +182,7 @@ void PPGPathTracer::handleIntersections() {
 	});
 }
 
-void PPGPathTracer::generateScatterRays() {
+void PPGPathTracer::generateScatterRays(int depth) {
 	PROFILE("Generate scatter rays");
 	ForAllQueued(guidedRayQueue, maxQueueSize, 
 		KRR_DEVICE_LAMBDA(const GuidedRayWorkItem &id) {
@@ -210,7 +210,7 @@ void PPGPathTracer::generateScatterRays() {
 				r.depth			 = w.depth + 1;
 				r.thp			 = w.thp * sample.f * fabs(sample.wi[2]) / sample.pdf;
 				if (any(r.thp)) {
-					nextRayQueue(w.depth)->push(r);
+					nextRayQueue(depth)->push(r);
 					/* guidance... */
 					if (r.depth <= MAX_TRAIN_DEPTH) {
 						guidedPathState->incrementDepth(r.pixelId, r.ray, dTree, dTreeVoxelSize,
@@ -255,7 +255,7 @@ void PPGPathTracer::render(RenderContext *context) {
 			handleIntersections();
 			if (enableNEE) traceShadow();
 			// [STEP#2.4] towards next bounce
-			generateScatterRays();
+			generateScatterRays(depth);
 		}
 	}
 	// write results of the current frame...

diff --git a/src/misc/render/ppg/integrator.h b/src/misc/render/ppg/integrator.h
@@ -33,7 +33,7 @@ class PPGPathTracer : public WavefrontPathTracer{
 	void handleHit();
 	void handleMiss();
 	void handleIntersections();
-	void generateScatterRays();
+	void generateScatterRays(int depth);
 	void traceClosest(int depth);
 	void traceShadow();
 

diff --git a/src/misc/render/zero_guiding/device.cu b/src/misc/render/zero_guiding/device.cu
@@ -48,6 +48,7 @@ extern "C" __global__ void KRR_RT_CH(Closest)() {
 	RayWorkItem r = getRayWorkItem();
 	int pixelId				  = launchParams.currentRayQueue->pixelId[getRayId()];
 	SampledWavelengths lambda = launchParams.pixelState->lambda[pixelId];
+	intr.medium				  = r.ray.medium; // if this surface is inside a medium
 	prepareSurfaceInteraction(intr, hitInfo, lambda);
 	if (launchParams.mediumSampleQueue && r.ray.medium) {
 		launchParams.mediumSampleQueue->push(r, intr, optixGetRayTmax());

diff --git a/src/misc/render/zero_guiding/integrator.cpp b/src/misc/render/zero_guiding/integrator.cpp
@@ -181,7 +181,7 @@ void ZeroGuidingPT::handleIntersections() {
 	});
 }
 
-void ZeroGuidingPT::generateScatterRays() {
+void ZeroGuidingPT::generateScatterRays(int depth) {
 	PROFILE("Generate scatter rays");
 	ForAllQueued(guidedRayQueue, maxQueueSize, 
 		KRR_DEVICE_LAMBDA(const GuidedRayWorkItem &id) {
@@ -209,7 +209,7 @@ void ZeroGuidingPT::generateScatterRays() {
 				r.depth			 = w.depth + 1;
 				r.thp			 = w.thp * sample.f * fabs(sample.wi[2]) / sample.pdf;
 				if (any(r.thp)) {
-					nextRayQueue(w.depth)->push(r);
+					nextRayQueue(depth)->push(r);
 					/* guidance... */
 					if (r.depth <= MAX_TRAIN_DEPTH) {
 						guidedPathState->incrementDepth(r.pixelId, r.ray, dTree, dTreeVoxelSize,
@@ -258,7 +258,7 @@ void ZeroGuidingPT::render(RenderContext *context) {
 			handleIntersections();
 			if (enableNEE) traceShadow();
 			// [STEP#2.4] towards next bounce
-			generateScatterRays();
+			generateScatterRays(depth);
 		}
 	}
 	// write results of the current frame...

diff --git a/src/misc/render/zero_guiding/integrator.h b/src/misc/render/zero_guiding/integrator.h
@@ -33,7 +33,7 @@ class ZeroGuidingPT : public WavefrontPathTracer{
 	void handleHit();
 	void handleMiss();
 	void handleIntersections();
-	void generateScatterRays();
+	void generateScatterRays(int depth);
 	void sampleMediumInteraction(int depth);
 	void sampleMediumScattering(int depth);
 	void traceClosest(int depth);

diff --git a/src/render/path/device.cu b/src/render/path/device.cu
@@ -136,6 +136,7 @@ extern "C" __global__ void KRR_RT_CH(Radiance)(){
 	HitInfo hitInfo			 = getHitInfo();
 	PathData *path			 = getPRD<PathData>();
 	SurfaceInteraction &intr = path->intr;
+	intr.medium				 = path->ray.medium; // if this surface is inside a medium
 	prepareSurfaceInteraction(intr, hitInfo, path->lambda);
 }
 

diff --git a/src/render/path/path.h b/src/render/path/path.h
@@ -47,17 +47,17 @@ struct LaunchParamsPT {
 };
 
 struct PathData {
-	Spectrum L{};		// total contribution to the current pixel
-	Spectrum throughput; // maintain the throughput of path
-	float pdf;					// BxDF sampling pdf from last scatter
-	int depth;					// number of vertices along the path
-	BSDFType bsdfType;			// the sampled type of the last scatter event
-	Sampler sampler;			// rng
-	SampledWavelengths lambda;	// sampled wavelength
-	LightSampler lightSampler;	// randomly choosing a light source
-	LightSampleContext ctx;		// *last* context used for direct light sampling
-	SurfaceInteraction intr;	// surface interaction of the *current* hit
-	Ray ray;					// The last scattered ray
+	Spectrum L{};			   // total contribution to the current pixel
+	Spectrum throughput;	   // maintain the throughput of path
+	float pdf;				   // BxDF sampling pdf from last scatter
+	int depth;				   // number of vertices along the path
+	BSDFType bsdfType;		   // the sampled type of the last scatter event
+	Sampler sampler;		   // rng
+	SampledWavelengths lambda; // sampled wavelength
+	LightSampler lightSampler; // randomly choosing a light source
+	LightSampleContext ctx;	   // *last* context used for direct light sampling
+	SurfaceInteraction intr;   // surface interaction of the *current* hit
+	Ray ray;				   // The last scattered ray
 };
 
 KRR_NAMESPACE_END
diff --git a/src/render/shading.h b/src/render/shading.h
@@ -128,9 +128,9 @@ KRR_DEVICE_FUNCTION void prepareSurfaceInteraction(SurfaceInteraction &intr, con
 	// transform local interaction to world space
 	// [TODO: refactor this, maybe via an integrated SurfaceInteraction struct]
 	intr.p		   = hitInfo.instance->getTransform() * intr.p;
-	intr.n		   = hitInfo.instance->getTransposedInverseTransform() * intr.n;
-	intr.tangent   = hitInfo.instance->getTransposedInverseTransform() * intr.tangent;
-	intr.bitangent = hitInfo.instance->getTransposedInverseTransform() * intr.bitangent;
+	intr.n		   = (hitInfo.instance->getTransposedInverseTransform() * intr.n).normalized();
+	intr.tangent   = (hitInfo.instance->getTransposedInverseTransform() * intr.tangent).normalized();
+	intr.bitangent = (hitInfo.instance->getTransposedInverseTransform() * intr.bitangent).normalized();
 
 	/* Safely return here since below are all material-related operations. */
 	if (intr.material == nullptr) return;
@@ -174,8 +174,8 @@ KRR_DEVICE_FUNCTION void prepareSurfaceInteraction(SurfaceInteraction &intr, con
 	} else if (material.mShadingModel == Material::ShadingModel::SpecularGlossiness) {
 		// [SPECULAR] RGB - Specular RGB; A - Glossiness
 		diffuse			  = baseColor;
-		specular		  = (RGB) spec; // specular reflectance
-		intr.sd.roughness = 1.f - spec[3];	//
+		specular		  = (RGB) spec;
+		intr.sd.roughness = 1.f - spec[3];	
 		intr.sd.metallic  = getMetallic(diffuse, specular);
 	} else assert(false);
 	intr.sd.diffuse	 = Spectrum::fromRGB(diffuse, SpectrumType::RGBBounded, lambda, colorSpace);