LS grid does not work particularily correctly yet.

assets/imgui/config.ini

@@ -4,7 +4,7 @@ Size=353,64
 Collapsed=0
 
 [Scene]
-Pos=-4,66
+Pos=-5,66
 Size=352,837
 Collapsed=0
 

assets/preferences/linespace_default.xml

 <linespace version="1.0">
-		<item name="subdivisions" value="25"/>
+		<item name="subdivisions" value="6"/>
 		<item name="radial-subdivision" value="50"/>
 		<item name="generator" value="gpu"/>
 </linespace>

assets/shaders/pathtracer/data/mesh_linespace.glsl

@@ -134,10 +134,13 @@ bool traverseLineSpace(const in Mesh mesh, int index, const in Ray local_ray, co
 	int face_tmin;
 	int face_tmax;
 
+	// LS can be empty.
+	if (mesh.linespaces[index].line_count == 0) return false;
+
 	Ray loc = local_ray;
 	loc.origin += 0.05f * loc.direction;
 
-	float offset = -1.f;//compMin(mesh.linespace.patch_size);
+	float offset = 0;//-1.f;//compMin(mesh.linespace.patch_size);
 
 	Ray offset_ray = local_ray;
 	offset_ray.origin += local_ray.direction * offset;
@@ -163,7 +166,7 @@ bool traverseLineSpace(const in Mesh mesh, int index, const in Ray local_ray, co
 		if(loc.intersectsTrianglePlane(near_data, mesh, t, nearer.barycentric.x, nearer.barycentric.y))
 		{
 			float nearest_distance = t-offset;
-			if(nearest_distance > 0 && max_distance > nearest_distance){
+			if(nearest_distance > 0 && max_distance > nearest_distance && t < t_min){
 				hit = nearer;
 				t_min = t;
 				//Found an intersected shaft. But we don't yet know whether it contains geometry, so look it up as a last step.
@@ -181,7 +184,7 @@ bool traverseLineSpace(const in Mesh mesh, int index, const in Ray local_ray, co
 		{
 			float farthest_distance = t-offset;
 
-			if(farthest_distance > 0 && max_distance > farthest_distance){
+			if(farthest_distance > 0 && max_distance > farthest_distance && t < t_min){
 				hit = nearer;
 				t_min = t;
 				//Found an intersected shaft. But we don't yet know whether it contains geometry, so look it up as a last step.

assets/shaders/pathtracer/generators/bvh/bvh_raygenerator.comp

@@ -31,5 +31,5 @@ void main()
 	vec2 random = settings.u_random_subpixel ? vec2(0, 0) : rand2D(random_seed + id, target_size.x*target_size.y);
 	traces_data[id].ray = u_camera.getRayFromPixel(vec2(gl_GlobalInvocationID.xy), random, vec2(target_size));
 	traces_data[id].hit.invalidate();
-	traces_data[id].ray.nearestIntersection(traces_data[id].hit, true);
+	traces_data[id].ray.nearestIntersection(traces_data[id].hit, false);
 }

src/libraries/raytrace/data/linespace.cpp

@@ -5,6 +5,7 @@
 #include <core/Time.h>
 #include <core/res/res.h>
 #include "pugixml/pugixml.hpp"
+#include <raytrace/intersect.h>
 
 namespace glare::raytrace
 {
@@ -44,10 +45,36 @@ namespace glare::raytrace
 	{
 		Log_Info << "Building Line Space for collector id " << collector.id() << "...";
 		core::ClockGL::instance().start();
-
 		m_bounds = collector.bounds();
+		auto grid = m_bounds.computeSubdivision(uniform_grid_subdivision);
+
+		int grid_index = uniform_grid_index;
+		glm::vec3 grid_index_3d;
+		grid_index_3d.x = grid_index % grid.resolution.x;
+		grid_index /= grid.resolution.x;
+		grid_index_3d.y = grid_index % grid.resolution.y;
+		grid_index_3d.z = grid_index / grid.resolution.y;
+
+		math::Bounds replacement;
+		replacement.min = m_bounds.min + glm::vec4(grid_index_3d * grid.size, 0);
+		replacement.max = replacement.min + glm::vec4(grid.size, 0);
+		m_bounds = replacement;
+
 		m_subdivision = m_bounds.subdivide(max_subdivisions);
 
+		m_filled = collector.triangles().cend() != std::find_if(collector.triangles().cbegin(), collector.triangles().cend(), [this, &collector](const TriangleIDs& tri)
+		{
+			math::Triangle triangle;
+			triangle.a = collector.vertices()[tri.indices[0]].position;
+			triangle.b = collector.vertices()[tri.indices[1]].position;
+			triangle.c = collector.vertices()[tri.indices[2]].position;
+			return intersect::intersects(triangle, m_bounds);
+		});
+
+		// if LS does not contain any triangles, don't try to generate.
+		if (!m_filled) 
+			return;
+
 		switch (generator)
 		{
 		default:
@@ -269,8 +296,8 @@ namespace glare::raytrace
 		data.bounds = m_bounds;
 		data.patch_size = m_subdivision.size;
 		data.resolution = m_subdivision.resolution;
-		data.lines = m_line_buffer.residentAddress();
-		data.line_count = lineCount();
+		data.lines = m_filled ? m_line_buffer.residentAddress() : 0;
+		data.line_count = m_filled ? lineCount() : 0;
 		return data;
 	}
 
@@ -288,4 +315,4 @@ namespace glare::raytrace
 	{
 		return m_subdivision;
 	}
-}
\ No newline at end of file
+}

src/libraries/raytrace/data/linespace.h

@@ -117,6 +117,7 @@ namespace glare::raytrace
 		math::Bounds m_bounds;
 		math::Subdivision m_subdivision;
 		core::Buffer m_line_buffer;
+		bool m_filled = false;
 
 		//Collection of startpatch-endpatch configurations for merging two loops
 		//in the generation process into one parallel loop.

src/libraries/raytrace/data/local_collector.cpp

@@ -2,6 +2,7 @@
 
 #include <raytrace/data/linespace.h>
 #include <core/rendering/batch_renderer.h>
+#include <pugixml/pugixml.hpp>
 
 namespace glare::raytrace
 {
@@ -56,11 +57,32 @@ namespace glare::raytrace
 		m_vertex_buffer->makeResident(gl::Access::eReadOnly);
 		m_triangle_buffer->makeResident(gl::Access::eReadOnly);
 
-		m_linespaces.resize(1, std::make_shared<Linespace>());
-		m_linespaces[0]->generate(*this, files::asset("preferences/linespace_default.xml"));
+		int subdiv_grid = 5; 
 
-		m_linespace_data.resize(1);
-		m_linespace_data[0] = m_linespaces[0]->data();
+		auto subdiv = m_bounds.computeSubdivision(subdiv_grid);
+		int count = subdiv.resolution.x * subdiv.resolution.y * subdiv.resolution.z;
+
+		pugi::xml_document doc;
+		doc.load_file(files::asset("preferences/linespace_default.xml").c_str());
+
+		const auto& linespace_tag = doc.child("linespace");
+
+		const int max_subdivisions = linespace_tag.find_child_by_attribute("item", "name", "subdivisions").attribute("value").as_int(16);
+		const std::string gen = linespace_tag.find_child_by_attribute("item", "name", "generator").attribute("value").as_string("cpu");
+		const Platform generator = gen == "gpu" ? Platform::eGPU : Platform::eCPU;
+
+		m_linespaces.resize(count);
+		for (int i = 0; i < count; ++i)
+		{
+			m_linespaces[i] = std::make_shared<Linespace>();
+			m_linespaces[i]->generate(*this, subdiv_grid, i, max_subdivisions, generator);
+		}
+
+		m_linespace_data.resize(count);
+		for (int i = 0; i < count; ++i)
+		{
+			m_linespace_data[i] = m_linespaces[i]->data();
+		}
 
 		m_linespace_buffer.upload(m_linespace_data, gl::BufferUsage::eDynamicDraw);
 	}