rt: implementing a simple path tracer

larc · Dec 4, 2023 · e845e7e · e845e7e
1 parent 38b3dc2
commit e845e7e
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Showing 4 changed files with 34 additions and 14 deletions.
diff --git a/include/gproshan/app_viewer.h b/include/gproshan/app_viewer.h
@@ -63,6 +63,7 @@ class app_viewer : public viewer
 
 		// Scenes
 		static bool process_simulate_scanner(viewer * p_view);
+		static bool process_scatter(viewer * p_view);
 
 		// Geometry
 		static bool process_sampling_4points(viewer * p_view);

diff --git a/include/gproshan/raytracing/utils.h b/include/gproshan/raytracing/utils.h
@@ -17,7 +17,7 @@ template <class T, unsigned int N = 16>
 struct random
 {
 	unsigned int previous;
-	
+
 	__host_device__
 	random(unsigned int p): previous(p) {}
 
@@ -40,7 +40,7 @@ struct random
 		previous = previous * 1664525 + 1013904223;
 		return T(previous & 0x00FFFFFF) / T(0x01000000);
 	}
-	
+
 	__host_device__
 	operator unsigned int & ()
 	{
@@ -168,38 +168,38 @@ struct t_eval_hit
 	}
 
 	__host_device__
-	bool scatter_reflect(const vec<T, 3> & v, vec<T, 3> & scattered, random<T> & rnd)
+	bool scatter_reflect(const vec<T, 3> & v, vec<T, 3> & scattered, random<T> & )
 	{
 		scattered = normalize(v - 2 * dot(v, normal) * normal);
 		return dot(scattered, normal) > 0;
 	}
 
 	__host_device__
-	bool scatter_refract(const vec<T, 3> & v, vec<T, 3> & scattered, random<T> & rnd)
+	bool scatter_refract(const vec<T, 3> & v, vec<T, 3> & scattered, random<T> & )
 	{
 		const float dvn = dot(v, normal);
 		const float d = 1 - Ni * Ni * (1 - dvn * dvn);
 
 		if(d <= 0) return false;
 
-		scattered = Ni * (v - dvn * normal) - normal * sqrt(d);
+		scattered = Ni * (v - dvn * normal) - normal * sqrtf(d);
 		return true;
 	}
 
 	__host_device__
-	bool scatter_diffuse(const vec<T, 3> & v, vec<T, 3> & scattered, random<T> & rnd)
+	bool scatter_diffuse(const vec<T, 3> & , vec<T, 3> & scattered, random<T> & rnd)
 	{
 		// random unit sphere
 		const T & theta = rnd() * 2 * M_PI;
-		const T & phi = acos(2 * rnd() - 1);
+		const T & phi = acosf(2 * rnd() - 1);
 		const T & r = cbrtf(rnd());
-		
-		const vec<T, 3> p = { r * sin(phi) * cos(theta)
-							, r * sin(phi) * sin(theta)
-							, r * cos(phi)
+
+		const vec<T, 3> p = { r * sinf(phi) * cosf(theta)
+							, r * sinf(phi) * sinf(theta)
+							, r * cosf(phi)
 							};
 
-		scattered = normalize(normal + scattered);
+		scattered = normalize(normal + p);
 
 		return true;
 	}

diff --git a/src/gproshan/app_viewer.cpp b/src/gproshan/app_viewer.cpp
@@ -52,7 +52,8 @@ void app_viewer::init()
 
 	add_menu("Scenes",
 	{
-		add_process("Scan Scene", process_simulate_scanner)
+		add_process("Scan Scene", process_simulate_scanner),
+		add_process("RT Scatter Points", process_scatter)
 	});
 
 	add_menu("Geometry",
@@ -219,6 +220,22 @@ bool app_viewer::process_simulate_scanner(viewer * p_view)
 	return true;
 }
 
+bool app_viewer::process_scatter(viewer * p_view)
+{
+	app_viewer * view = (app_viewer *) p_view;
+
+	rt::eval_hit h;
+	std::vector<vertex> scatter(100);
+
+	rt::random<real_t> rnd(0xABCDEF);
+	for(vertex & v: scatter)
+		h.scatter_diffuse({}, v, rnd);
+
+	view->add_mesh(new che(scatter.data(), scatter.size(), nullptr, 0));
+
+	return false;
+}
+
 
 // Geometry
 bool app_viewer::process_sampling_4points(viewer * p_view)

diff --git a/src/gproshan/raytracing/optix.cu b/src/gproshan/raytracing/optix.cu
@@ -86,12 +86,14 @@ extern "C" __global__ void __closesthit__radiance()
 							return occluded != 0;
 						});
 
+	random<float> rnd = optixGetPayload_2();
 	color *= attenuation;
 	position = hit.position;
 
-	random<float> rnd = optixGetPayload_2();
 	if(!hit.scatter_mat(scattered, scattered, rnd))
 		attenuation = 0;
+
+	attenuation /= 2;
 	optixSetPayload_2(rnd);
 }