New version of the samples and tutorials based on KHR_ray_tracing

ray_tracing_instances/shaders/raytrace.rchit

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+#version 460
+#extension GL_EXT_ray_tracing : require
+#extension GL_EXT_nonuniform_qualifier : enable
+#extension GL_EXT_scalar_block_layout : enable
+#extension GL_GOOGLE_include_directive : enable
+#include "raycommon.glsl"
+#include "wavefront.glsl"
+
+hitAttributeEXT vec3 attribs;
+
+// clang-format off
+layout(location = 0) rayPayloadInEXT hitPayload prd;
+layout(location = 1) rayPayloadEXT bool isShadowed;
+
+layout(binding = 0, set = 0) uniform accelerationStructureEXT topLevelAS;
+
+layout(binding = 2, set = 1, scalar) buffer ScnDesc { sceneDesc i[]; } scnDesc;
+layout(binding = 5, set = 1, scalar) buffer Vertices { Vertex v[]; } vertices[];
+layout(binding = 6, set = 1) buffer Indices { uint i[]; } indices[];
+
+layout(binding = 1, set = 1, scalar) buffer MatColorBufferObject { WaveFrontMaterial m[]; } materials[];
+layout(binding = 3, set = 1) uniform sampler2D textureSamplers[];
+layout(binding = 4, set = 1)  buffer MatIndexColorBuffer { int i[]; } matIndex[];
+
+// clang-format on
+
+layout(push_constant) uniform Constants
+{
+  vec4  clearColor;
+  vec3  lightPosition;
+  float lightIntensity;
+  int   lightType;
+}
+pushC;
+
+
+void main()
+{
+  // Object of this instance
+  uint objId = scnDesc.i[gl_InstanceID].objId;
+
+  // Indices of the triangle
+  ivec3 ind = ivec3(indices[objId].i[3 * gl_PrimitiveID + 0],   //
+                    indices[objId].i[3 * gl_PrimitiveID + 1],   //
+                    indices[objId].i[3 * gl_PrimitiveID + 2]);  //
+  // Vertex of the triangle
+  Vertex v0 = vertices[objId].v[ind.x];
+  Vertex v1 = vertices[objId].v[ind.y];
+  Vertex v2 = vertices[objId].v[ind.z];
+
+  const vec3 barycentrics = vec3(1.0 - attribs.x - attribs.y, attribs.x, attribs.y);
+
+  // Computing the normal at hit position
+  vec3 normal = v0.nrm * barycentrics.x + v1.nrm * barycentrics.y + v2.nrm * barycentrics.z;
+  // Transforming the normal to world space
+  normal = normalize(vec3(scnDesc.i[gl_InstanceID].transfoIT * vec4(normal, 0.0)));
+
+
+  // Computing the coordinates of the hit position
+  vec3 worldPos = v0.pos * barycentrics.x + v1.pos * barycentrics.y + v2.pos * barycentrics.z;
+  // Transforming the position to world space
+  worldPos = vec3(scnDesc.i[gl_InstanceID].transfo * vec4(worldPos, 1.0));
+
+  // Vector toward the light
+  vec3  L;
+  float lightIntensity = pushC.lightIntensity;
+  float lightDistance  = 100000.0;
+  // Point light
+  if(pushC.lightType == 0)
+  {
+    vec3 lDir      = pushC.lightPosition - worldPos;
+    lightDistance  = length(lDir);
+    lightIntensity = pushC.lightIntensity / (lightDistance * lightDistance);
+    L              = normalize(lDir);
+  }
+  else  // Directional light
+  {
+    L = normalize(pushC.lightPosition - vec3(0));
+  }
+
+  // Material of the object
+  int               matIdx = matIndex[objId].i[gl_PrimitiveID];
+  WaveFrontMaterial mat    = materials[objId].m[matIdx];
+
+
+  // Diffuse
+  vec3 diffuse = computeDiffuse(mat, L, normal);
+  if(mat.textureId >= 0)
+  {
+    uint txtId = mat.textureId + scnDesc.i[gl_InstanceID].txtOffset;
+    vec2 texCoord =
+        v0.texCoord * barycentrics.x + v1.texCoord * barycentrics.y + v2.texCoord * barycentrics.z;
+    diffuse *= texture(textureSamplers[txtId], texCoord).xyz;
+  }
+
+  vec3  specular    = vec3(0);
+  float attenuation = 1;
+
+  // Tracing shadow ray only if the light is visible from the surface
+  if(dot(normal, L) > 0)
+  {
+    float tMin   = 0.001;
+    float tMax   = lightDistance;
+    vec3  origin = gl_WorldRayOriginEXT + gl_WorldRayDirectionEXT * gl_HitTEXT;
+    vec3  rayDir = L;
+    uint  flags  = gl_RayFlagsTerminateOnFirstHitEXT | gl_RayFlagsOpaqueEXT
+                 | gl_RayFlagsSkipClosestHitShaderEXT;
+    isShadowed = true;
+    traceRayEXT(topLevelAS,  // acceleration structure
+                flags,       // rayFlags
+                0xFF,        // cullMask
+                0,           // sbtRecordOffset
+                0,           // sbtRecordStride
+                1,           // missIndex
+                origin,      // ray origin
+                tMin,        // ray min range
+                rayDir,      // ray direction
+                tMax,        // ray max range
+                1            // payload (location = 1)
+    );
+
+    if(isShadowed)
+    {
+      attenuation = 0.3;
+    }
+    else
+    {
+      // Specular
+      specular = computeSpecular(mat, gl_WorldRayDirectionEXT, L, normal);
+    }
+  }
+
+  prd.hitValue = vec3(lightIntensity * attenuation * (diffuse + specular));
+}