Misaki
6800810369
Added new files for BVH, AABB, and Debug functionalities. Added new utility functions in Common.h. Added gamma correction function in PostProcessing.h. Changed the return type of path_trace to vec4s for alpha blending. Changed BSDF function signatures to include sample index and bounce. Changed the BSDF.h to replace inline functions with declarations. Changed the Light and SkyLight evaluation functions to include throughput and sample index. Changed the sphere creation function in GeometryUtilities.h for better quality. Changed the scene structure to include a BVH tree for improved ray intersection. Changed the scene initialization parameters for better performance. Created new Debug functions for ray intersection counting. Created new functions for triangle collection management in Triangle.c. Improved pixel updating logic in Window.c. Improved ray intersection performance with new BVH implementation. Removed unused includes from Common.h. Removed old library linking methods in CMakeLists.txt.
109 lines
4.3 KiB
C
109 lines
4.3 KiB
C
#include "Algorithm/PathTracing.h"
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#include "Algorithm/RayIntersection.h"
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#include "Algorithm/BSDF.h"
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#include "Lighting/LightEvaluation.h"
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// TODO: Implement a faster methods like BVH, KD-Tree or uniform grid acceleration
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// TODO: Split the diffuse and specular into different Monte Carlo, so we can decide the sample count for each one
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vec4s path_trace(const scene_t* scene, ray_t ray, uint32_t sample_index, uint16_t max_depth)
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{
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const triangle_collection_t* triangles = &scene->triangles;
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const bvh_tree_t* bvh_tree = &scene->bvh_tree;
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const material_collection_t* materials = &scene->materials;
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const light_collection_t* lights = &scene->lights;
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vec4s accumulated_color = glms_vec4_zero();
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vec3s throughput = glms_vec3_one();
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ray_t active_ray = ray;
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vec3s prev_normal = glms_vec3_zero();
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float pdf_bsdf = 1.0f;
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uint16_t depth = 0;
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while (depth < max_depth)
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{
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hit_result_t closest_hit = ray_intersect_scene(active_ray, scene);
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if (!closest_hit.hit)
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{
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vec3s sky_light = evaluate_bsdf_sky(scene, NULL, throughput, sample_index);
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if (depth > 0)
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{
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// Have to multiply the weight since we evaluate the sky at each bounce
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float pdf_nee = pdf_cosine_weighted_hemisphere(prev_normal, active_ray.direction);
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float weight = power_heuristic(pdf_bsdf, pdf_nee);
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sky_light = glms_vec3_scale(sky_light, weight);
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}
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accumulated_color = glms_vec4_add(accumulated_color, glms_vec4(sky_light, 1.0f)); // TODO: Physical Skybox
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break;
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}
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// Add the emission of the hit material to the accumulated color
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material_t* hit_material = &materials->buffer[triangles->buffer[closest_hit.triangle_id].material_id];
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vec3s emission = hit_material->emission;
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accumulated_color = glms_vec4_add(accumulated_color, glms_vec4(glms_vec3_mul(throughput, emission), 1.0f));
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light_shading_context_t light_context = {
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.normal = closest_hit.normal,
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.hit_point = closest_hit.point,
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.wo = active_ray.direction,
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.bounce_depth = depth,
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.bvh_tree = bvh_tree,
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.material = hit_material
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};
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// Running the light loop.
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// TODO: Implementing other light types.
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for (uint32_t i = 0; i < lights->directional_light_count; i++)
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{
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vec3s l = evaluate_bsdf_directional(lights->directional_lights[i], &light_context, throughput, sample_index);
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accumulated_color = glms_vec4_add(accumulated_color, glms_vec4(l, 1.0f));
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}
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vec3s sky_light = evaluate_bsdf_sky(scene, &light_context, throughput, sample_index);
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accumulated_color = glms_vec4_add(accumulated_color, glms_vec4(sky_light, 1.0f));
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// Bounce and prepare for the next iteration
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vec3s wo = glms_vec3_negate(active_ray.direction); // We need to negate the direction of the incoming ray
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vec3s wi = sample_material_bsdf(hit_material, closest_hit.normal, wo, sample_index, depth, &pdf_bsdf);
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if (pdf_bsdf <= 0.0f)
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{
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break;
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}
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shading_context_t shading_context = {
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.normal = closest_hit.normal,
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.wi = wi,
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.wo = wo
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};
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vec3s bsdf = evaluate_material_bsdf(hit_material, &shading_context);
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float cos_theta = fmaxf(0.0f, glms_vec3_dot(wi, closest_hit.normal));
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throughput = glms_vec3_mul(throughput, glms_vec3_scale(bsdf, cos_theta / pdf_bsdf));
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// We do Russian roulette to decide whether to continue tracing or terminate the path
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if (depth > 2)
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{
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float q = fminf(glms_vec3_max(throughput), 0.95f);
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float rr_sample = sobol_sample(sample_index, sobol_get_dimension(depth, PRNG_TERMINATE));
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// float rr_sample = random_float();
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if (rr_sample > q)
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{
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break; // Terminate the path
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}
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// Keep the energy of the path by scaling the throughput
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throughput = glms_vec3_scale(throughput, 1.0f / q);
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}
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active_ray.origin = glms_vec3_add(closest_hit.point, glms_vec3_scale(closest_hit.normal, 1.192092896e-04F));
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active_ray.direction = wi;
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prev_normal = closest_hit.normal;
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depth++;
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}
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return accumulated_color;
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}
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