From 4a6aae00f61814871f48c2c6a2b86f1b57b206ba Mon Sep 17 00:00:00 2001 From: ladevieq Date: Tue, 25 May 2021 23:23:44 +0200 Subject: Fix BVH traversal and use PCG instead of wang hash --- shaders/compute.comp | 35 +++++++++++++++++++++-------------- 1 file changed, 21 insertions(+), 14 deletions(-) (limited to 'shaders/compute.comp') diff --git a/shaders/compute.comp b/shaders/compute.comp index 3090e3b..c43d48b 100644 --- a/shaders/compute.comp +++ b/shaders/compute.comp @@ -91,20 +91,17 @@ vec3 at(ray r, float t) { return r.origin + r.direction * t; } - -uint wang_hash(inout uint seed) +uint pcg_hash(inout uint seed) { - seed = (seed ^ 61) ^ (seed >> 16); - seed *= 9; - seed = seed ^ (seed >> 4); - seed *= 0x27d4eb2d; - seed = seed ^ (seed >> 15); - return seed; + uint state = seed; + seed *= 747796405u + 2891336453u; + uint word = ((state >> ((state >> 28u) + 4u)) ^ state) * 277803737u; + return (word >> 22u) ^ word; } float rand(inout uint seed) { - return float(wang_hash(seed)) / 4294967296.0; + return float(pcg_hash(seed)) / 4294967296.0; } vec3 unit_vec(inout uint seed) { @@ -203,14 +200,24 @@ bool hit_node(ray r, float min_t, float max_t, out hit_info info) { int stack_id = -1; int stack[64]; bvh_node current_node = nodes[0]; + bool hit = false; while(true) { // Reached a leaf if (current_node.sphere_id != -1) { - hit_sphere(spheres[current_node.sphere_id], r, min_t, closest_t, temp_info); - info = temp_info; - closest_t = temp_info.t; - continue; + if (hit_sphere(spheres[current_node.sphere_id], r, min_t, closest_t, temp_info)) { + info = temp_info; + closest_t = temp_info.t; + hit = true; + } + + if (stack_id >= 0) { + current_node = nodes[stack[stack_id]]; + stack_id--; + continue; + } + + return hit; } bool hit_left = hit_aabb(nodes[current_node.left].bb, r, min_t, max_t); @@ -240,7 +247,7 @@ bool hit_node(ray r, float min_t, float max_t, out hit_info info) { bool hit_spheres(ray r, float min_t, float max_t, out hit_info info) { float closest_t = max_t; hit_info temp_info; - bool hit = false; + // bool hit = false; // for (uint sphere_index = 0; sphere_index <= spheres_count; sphere_index++) { // if (spheres[sphere_index].radius > 0.0 && hit_sphere(spheres[sphere_index], r, min_t, closest_t, temp_info)) { // info = temp_info; -- cgit v1.3