refactor(shaders): Apply common utilities to renderer shaders

Updated renderer_3d.wgsl, mesh_render.wgsl, skybox.wgsl to use
common_utils functions. Registered snippet in ShaderComposer.

Updated demo_assets.txt with SHADER_MATH_COMMON_UTILS entry.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

1 files changed, 3 insertions, 4 deletions

diff --git a/assets/final/shaders/mesh_render.wgsl b/assets/final/shaders/mesh_render.wgsl
index 068efbc..7390b06 100644
--- a/assets/final/shaders/mesh_render.wgsl
+++ b/assets/final/shaders/mesh_render.wgsl
@@ -1,4 +1,5 @@
 #include "common_uniforms"
+#include "math/common_utils"
 
 @group(0) @binding(0) var<uniform> globals: GlobalUniforms;
 @group(0) @binding(1) var<storage, read> object_data: ObjectsBuffer;
@@ -33,10 +34,8 @@ fn vs_main(in: VertexInput, @builtin(instance_index) instance_index: u32) -> Ver
     out.clip_pos = globals.view_proj * world_pos;
     out.world_pos = world_pos.xyz;
     
-    // Use transpose of inverse for normals
-    // Note: mat3x3 constructor takes columns, so passing rows gives us transpose
-    let normal_matrix = mat3x3<f32>(obj.inv_model[0].xyz, obj.inv_model[1].xyz, obj.inv_model[2].xyz);
-    out.normal = normalize(normal_matrix * in.normal);
+    // Transform normal from local to world space
+    out.normal = transform_normal(obj.inv_model, in.normal);
     
     out.uv = in.uv;
     out.color = obj.color;