docs(cnn_v3): clarify --output is a base dir, not a frame_### pattern

1 files changed, 9 insertions, 6 deletions

diff --git a/cnn_v3/training/blender_export.py b/cnn_v3/training/blender_export.py
index 76180fd..bb0d3d9 100644
--- a/cnn_v3/training/blender_export.py
+++ b/cnn_v3/training/blender_export.py
@@ -4,16 +4,17 @@ Configures render passes and a compositor File Output node,
 then renders the current scene to a multi-layer EXR.
 
 Usage (headless):
-    blender -b scene.blend -P blender_export.py -- --output renders/frame_###
+    blender -b scene.blend -P blender_export.py -- --output /tmp/renders/
 
     # List available view layers in the blend file:
     blender -b scene.blend -P blender_export.py -- --view-layer ?
 
     # Use a specific view layer:
-    blender -b scene.blend -P blender_export.py -- --output renders/frame_### --view-layer "MyLayer"
+    blender -b scene.blend -P blender_export.py -- --output /tmp/renders/ --view-layer "MyLayer"
 
-Each '#' in the output path is replaced by Blender with the frame number (zero-padded).
-The script writes one multi-layer EXR per frame containing all required passes.
+--output is the base directory for the compositor File Output node. Blender appends
+the slot name and frame number to each file (e.g. /tmp/renders/Combined0001.exr).
+Use // as a prefix to resolve relative to the .blend file directory.
 
 G-buffer pass mapping:
     Combined  → training target RGBA (beauty)
@@ -42,8 +43,10 @@ def parse_args():
         description="Configure Blender render passes and export multi-layer EXR."
     )
     parser.add_argument(
-        "--output", default="//renders/frame_###",
-        help="Output path prefix (use ### for frame number padding). Default: //renders/frame_###",
+        "--output", default="//renders/",
+        help="Base output directory for compositor File Output node. "
+             "Blender appends slot name + frame number (e.g. Combined0001.exr). "
+             "Use // for blend file directory. Default: //renders/",
     )
     parser.add_argument("--width",       type=int, default=640,  help="Render width in pixels (default: 640)")
     parser.add_argument("--height",      type=int, default=360,  help="Render height in pixels (default: 360)")