docs: Add Task #68 for mesh wireframe rendering in debug mode

Adds low-priority task to enhance visual debug mode with wireframe overlay
for mesh objects.

**Current State:**
Visual debug mode shows normals for all objects (SDF primitives and meshes)

**Proposed Enhancement:**
Show triangle edges as lines for mesh objects to visualize mesh structure

**Implementation:**
- Extend VisualDebug class with mesh wireframe function
- For each triangle: draw 3 lines connecting vertices (v0→v1, v1→v2, v2→v0)
- Transform vertices to world space using model matrix
- Use distinct color (cyan for edges, yellow for normals)
- Guard with !STRIP_ALL to avoid production overhead

**Use Cases:**
- Verify mesh topology and face orientation
- Debug mesh loading/transformation issues
- Visualize mesh structure alongside SDF primitives
- Check for degenerate triangles or mesh artifacts

**Technical Approach:**
- Access mesh via AssetManager::GetMeshAsset()
- Iterate through indices in groups of 3
- Use existing VisualDebug::draw_line() API
- Transform: world_pos = model_matrix * local_pos

**Priority:** Low (debug visualization only, not production feature)

This complements the existing normal visualization and improves mesh
debugging capabilities.

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

1 files changed, 20 insertions, 0 deletions

diff --git a/TODO.md b/TODO.md
index 76a2ba0..8394972 100644
--- a/TODO.md
+++ b/TODO.md
@@ -350,6 +350,26 @@ This file tracks prioritized tasks with detailed attack plans.
   - Increased particle usage: Added 5 ParticleSprayEffect instances throughout demo (6b, 12b, 17b, 24b, 56b)
   - Result: Particles now render as fading transparent circles instead of opaque squares
 - [ ] **Task #55: SDF Random Planes Intersection**: Implement `sdPolyhedron` (crystal/gem shapes) via plane intersection.
+- [ ] **Task #68: Visual Debug - Mesh Wireframe Rendering**: Show triangle edges as lines for mesh objects
+  - **Current**: Visual debug mode shows normals for all objects (SDF and meshes)
+  - **Goal**: Add wireframe overlay for mesh objects to visualize triangle structure
+  - **Implementation**:
+    - Extend `VisualDebug` class with mesh wireframe rendering function
+    - For each mesh triangle: draw 3 lines connecting vertices (v0→v1, v1→v2, v2→v0)
+    - Use world-space positions (transform by model matrix)
+    - Color: distinct from normals (e.g., cyan for edges, yellow for normals)
+    - Only render when debug mode enabled (`!STRIP_ALL`)
+  - **Use Cases**:
+    - Verify mesh topology and face orientation
+    - Debug mesh loading/transformation issues
+    - Visualize mesh deformation or animation
+    - Check for degenerate triangles or mesh artifacts
+  - **Technical Details**:
+    - Access mesh data via `AssetManager::GetMeshAsset()`
+    - Iterate through indices in groups of 3 (triangles)
+    - Draw lines using existing `VisualDebug::draw_line()` API
+    - Transform vertices: `world_pos = model_matrix * local_pos`
+  - **Priority**: Low (debug visualization, not production feature)
 - [ ] **Task #54: Tracy Integration**: Integrate Tracy debugger for performance profiling.
 - [ ] **Task #58: Advanced Shader Factorization**: Further factorize WGSL code into smaller, reusable snippets.
 - [ ] **Task #59: Comprehensive RNG Library**: Add WGSL snippets for float/vec2/vec3 noise (Perlin, Gyroid, etc.) and random number generators.