rt: simplify bounce computations

use simpler polygon sampling
use smaller texture lods

ref_vk/shaders/bounce.comp

@@ -3,6 +3,7 @@
 #extension GL_EXT_nonuniform_qualifier : enable
 #extension GL_EXT_ray_query: require
 
+#define RAY_BOUNCE
 #define RAY_QUERY
 layout(local_size_x = 8, local_size_y = 8, local_size_z = 1) in;
 

ref_vk/shaders/light_polygon.glsl

@@ -6,6 +6,18 @@
 #include "noise.glsl"
 #include "utils.glsl"
 
+#define DO_ALL_IN_CLUSTER 1
+
+#ifndef RAY_BOUNCE
+#define PROJECTED
+//#define SOLID
+//#define SIMPLE_SOLID
+#else
+//#define PROJECTED
+//#define SOLID
+//#define SIMPLE_SOLID
+#endif
+
 struct SampleContext {
 	mat4x3 world_to_shading;
 };
@@ -159,11 +171,6 @@ vec4 getPolygonLightSampleSolid(vec3 P, vec3 view_dir, SampleContext ctx, const
 	return vec4(light_dir, contrib);
 }
 
-#define DO_ALL_IN_CLUSTER 1
-//#define PROJECTED
-//#define SOLID
-#define SIMPLE_SOLID
-
 void sampleSinglePolygonLight(in vec3 P, in vec3 N, in vec3 view_dir, in SampleContext ctx, in MaterialProperties material, in PolygonLight poly, inout vec3 diffuse, inout vec3 specular) {
 	// TODO cull by poly plane
 

ref_vk/shaders/ray_primary_hit.glsl

@@ -13,7 +13,11 @@ layout(set = 0, binding = 2) uniform UBO { UniformBuffer ubo; } ubo;
 layout(set = 0, binding = 7) uniform samplerCube skybox;
 
 vec4 sampleTexture(uint tex_index, vec2 uv, vec4 uv_lods) {
+#ifndef RAY_BOUNCE
 	return textureGrad(textures[nonuniformEXT(tex_index)], uv, uv_lods.xy, uv_lods.zw);
+#else
+	return textureLod(textures[nonuniformEXT(tex_index)], uv, 2.);
+#endif
 }
 
 void primaryRayHit(rayQueryEXT rq, inout RayPayloadPrimary payload) {
@@ -34,6 +38,7 @@ void primaryRayHit(rayQueryEXT rq, inout RayPayloadPrimary payload) {
 		payload.material_rmxx.r = (kusok.tex_roughness > 0) ? sampleTexture(kusok.tex_roughness, geom.uv, geom.uv_lods).r : kusok.roughness;
 		payload.material_rmxx.g = (kusok.tex_metalness > 0) ? sampleTexture(kusok.tex_metalness, geom.uv, geom.uv_lods).r : kusok.metalness;
 
+#ifndef RAY_BOUNCE
 		const uint tex_normal = kusok.tex_normalmap;
 		vec3 T = geom.tangent;
 		if (tex_normal > 0 && dot(T,T) > .5) {
@@ -43,6 +48,7 @@ void primaryRayHit(rayQueryEXT rq, inout RayPayloadPrimary payload) {
 			const vec3 tnorm = sampleTexture(tex_normal, geom.uv, geom.uv_lods).xyz * 2. - 1.; // TODO is this sampling correct for normal data?
 			geom.normal_shading = normalize(TBN * tnorm);
 		}
+#endif
 	}
 
 	payload.normals_gs.xy = normalEncode(geom.normal_geometry);