ADD: Ray tracing shadow with Clipmap shadow blending

shaders/input_structures.glsl

@@ -16,6 +16,12 @@ layout(set = 0, binding = 0) uniform  SceneData{
     mat4 lightViewProjCascades[4];
     // View-space split distances for selecting cascades (x,y,z,w)
     vec4 cascadeSplitsView;
+    // Ray-query settings (packed)
+    // rtOptions.x = enabled (1/0)
+    // rtOptions.y = cascade bitmask (bit i => cascade i assisted)
+    uvec4 rtOptions;
+    // rtParams.x = N·L threshold; others reserved
+    vec4  rtParams;
 } sceneData;
 
 layout(set = 1, binding = 0) uniform GLTFMaterialData{