rtx: slightly improve fake poc lighting

ref_vk/TODO.md

@@ -1,13 +1,14 @@
 ## 2021-06-05, E103
 - [x] rtx: dynamic surface lights / dynamic light clusters
 - [x] rtx: animated textures
+- [x] rtx: attenuate surface lights by normal
 
 # Next
-- [ ] rtx: attenuate surface lights by normal
+- [ ] run under asan
 - [ ] rtx: better memory handling
 	- [ ] robust tracking of memory hierarchies: global/static, map, frame
 	- or just do a generic allocator with compaction?
-- [ ] rtx: better light culling: normal, bsp visibility, light volumes and intensity, ...
+- [ ] rtx: better light culling: normal, bsp visibility, light volumes and intensity, sort by intensity, etc
 - [ ] rtx: live rad file reloading (or other solution for tuning lights)
 - [ ] rtx: restore dynamic stuff like particles, beams, etc
 - [ ] rtx: emissive particles
@@ -29,6 +30,8 @@
 - [ ] studio models: fix lighting: should have white texture instead of lightmap OR we could write nearest surface lightmap coords to fake light
 
 # Planned
+- [ ] rtx: too many emissive lights in c3a1b
+- [ ] rtx: c3a1b: assert model->size >= build_size.accelerationStructureSize failed at vk_rtx.c:347
 - [ ] studio models: pre-compute buffer sizes and allocate them at once
 - [ ] rtx: denoise
 	- [ ] non local means ?
@@ -70,7 +73,6 @@
 
 # Someday
 - [ ] nvnsight into buffer memory and stuff
-- [ ] run under asan
 - [ ] start building command buffers in beginframe
 - [ ] multiple frames in flight (#nd cmdbuf, ...)
 - [ ] cleanup unused stuff in vk_studio.c

ref_vk/shaders/rtx.comp

@@ -430,7 +430,7 @@ void main() {
 					//C += kc * vec3(hash(float(kusok_index)), hash(float(kusok_index)+15.43), hash(float(kusok_index)+34.));//kusok.emissive.rgb;
 					//C = vec3(1., 0., 1.);
 					if (bounce == 0)
-						C += kc * emissive;
+						C += kc * emissive * baseColor;
 					continue;
 				}
 
@@ -462,12 +462,14 @@ void main() {
 					// const vec3 n3 = vertices[vi3].normal;
 
 					vec3 light_dir = sample_pos - pos;
-					if (dot(light_dir, n1) >= 0.) {
+					float light_dot = -dot(light_dir, n1);
+					if (light_dot <= 0.) {
 						//C = vec3(1., 0., 1.);
 						continue;
 					}
 
 					const float light_dist = length(light_dir);
+					light_dot /= light_dist;
 					light_dir /= light_dist;
 					if (shadowed(pos, light_dir, light_dist - shadow_offset_fudge)) {
 						//C = vec3(0., 1., 0.);
@@ -476,7 +478,7 @@ void main() {
 
 					// TODO
 					const float brightness_fudge = 5.;
-					C += sampling_light_scale * brightness_fudge * kc * baseColor * emissive * dot(light_dir, normal) / (light_dist * light_dist);
+					C += light_dot * sampling_light_scale * brightness_fudge * kc * baseColor * emissive * dot(light_dir, normal) / (light_dist * light_dist);
 
 					// Sample just one triangle
 					break;