webgpu sponza

examples/Sponza/raygen.glsl

@@ -0,0 +1,52 @@
+#version 460
+#extension GL_EXT_ray_tracing : enable
+#extension GL_EXT_shader_image_load_formatted : enable
+#extension GL_EXT_shader_explicit_arithmetic_types_int16 : enable
+#extension GL_EXT_descriptor_heap : enable
+#extension GL_EXT_nonuniform_qualifier : enable
+
+// Specialization constant set from descriptorHeap.bufferStartElement —
+// shared with closesthit.glsl. The TLAS lives at descriptor_heap slot
+// `bufferStart` (it's an SSBO-typed entry), the per-frame output image
+// at heap slot 0.
+layout(constant_id = 0) const uint16_t bufferStart = 0us;
+layout(descriptor_heap) uniform accelerationStructureEXT topLevelAS[];
+layout(descriptor_heap) uniform writeonly image2D image[];
+
+layout(location = 0) rayPayloadEXT vec3 hitValue;
+
+void main() {
+    uvec2 pixel      = gl_LaunchIDEXT.xy;
+    uvec2 resolution = gl_LaunchSizeEXT.xy;
+    vec2  uv         = (vec2(pixel) + 0.5) / vec2(resolution);
+    vec2  ndc        = uv * 2.0 - 1.0;
+
+    // Camera positioned to look down the Sponza atrium axis. Sponza-OBJ
+    // from McGuire's archive is roughly 30 units wide × 13 tall × 18 deep,
+    // axis-aligned, with the floor near y=0 and the atrium centered on
+    // origin. -X faces the long end, so we sit inside looking +X.
+    vec3  origin    = vec3(-10.0, 5.0, 0.0);
+    float aspect    = float(resolution.x) / float(resolution.y);
+    float fov       = radians(70.0);
+    float tanHalf   = tan(fov * 0.5);
+    vec3  direction = normalize(vec3(
+        ndc.x * aspect * tanHalf,
+        -ndc.y * tanHalf,
+        1.0));
+
+    // Rotate +Z forward → +X forward (90° about Y).
+    direction = vec3(direction.z, direction.y, -direction.x);
+
+    traceRayEXT(
+        topLevelAS[bufferStart],
+        gl_RayFlagsNoneEXT,
+        0xff,
+        0, 0, 0,
+        origin,
+        0.001,
+        direction,
+        10000.0,
+        0);
+
+    imageStore(image[0], ivec2(pixel), vec4(hitValue, 1.0));
+}