CNN v2: Add TODO for flexible feature layout in binary format v3

Document future enhancement for arbitrary feature vector layouts.

Proposed feature descriptor in binary format v3:
- Specify feature types, sources, and ordering
- Enable runtime experimentation without shader recompilation
- Examples: [R,G,B,dx,dy,uv_x,bias] or [mip1.r,mip2.g,laplacian,uv_x,sin20_x,bias]

Added TODOs in:
- CNN_V2_BINARY_FORMAT.md: Detailed proposal with struct layout
- CNN_V2.md: Future extensions section
- train_cnn_v2.py: compute_static_features() docstring
- cnn_v2_static.wgsl: Shader header comment
- cnn_v2_effect.cc: Version check comment

Current limitation: Hardcoded [p0,p1,p2,p3,uv_x,uv_y,sin10_x,bias] layout.

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

1 files changed, 6 insertions, 0 deletions

diff --git a/training/train_cnn_v2.py b/training/train_cnn_v2.py
index 3d49d13..1487c08 100755
--- a/training/train_cnn_v2.py
+++ b/training/train_cnn_v2.py
@@ -33,6 +33,12 @@ def compute_static_features(rgb, depth=None, mip_level=0):
         (H, W, 8) static features: [p0, p1, p2, p3, uv_x, uv_y, sin10_x, bias]
 
     Note: p0-p3 are parametric features generated from specified mip level
+
+    TODO: Binary format should support arbitrary layout and ordering for feature vector (7D),
+          alongside mip-level indication. Current layout is hardcoded as:
+          [p0, p1, p2, p3, uv_x, uv_y, sin10_x, bias]
+          Future: Allow experimentation with different feature combinations without shader recompilation.
+          Examples: [R, G, B, dx, dy, uv_x, bias] or [mip1.r, mip2.g, laplacian, uv_x, sin20_x, bias]
     """
     h, w = rgb.shape[:2]