fix: Resolve mascot geometry issue with billboard plane approach

**Critical Fixes:**

1. **Billboard Plane for 3D Mode** (blender_script.py:322-337)
   - Replaced UV sphere with flat plane
   - Preserves flat fox design (no more distortion!)
   - Mascot now fully recognizable in 3D mode
   - Added transparency support and proper material settings

2. **Render Engine Name Compatibility** (blender_script.py:732-745)
   - Fixed 'EEVEE' -> 'BLENDER_EEVEE' mapping
   - Added engine_map for config normalization
   - Works with Blender 4.0.2 naming convention

**Test Configs Added:**
- config_hybrid_test.yaml: Quick 1-second hybrid mode test
- config_3d_billboard_test.yaml: Quick 1-second 3D billboard test

**Results:**
✓ Hybrid mode: Recognizable 2D fox on 3D stage
✓ 3D mode: Recognizable fox on billboard with full 3D features
✓ All production features (PBR, lighting, stage) working
✓ No more abstract sphere - fox is clear and identifiable

This resolves the output regression issue where production features
improved but mascot recognizability decreased. Now both are excellent!

Author: claude

blender_script.py

@@ -319,18 +319,29 @@ def create_mascot_placeholder(self):
 
         mascot_image = self.config.get('inputs', {}).get('mascot_image')
 
-        # For now, create a simple placeholder mesh
-        # TODO: Implement image-to-mesh conversion with rigging
-        bpy.ops.mesh.primitive_uv_sphere_add(radius=1, location=(0, 0, 1))
+        # Use billboard plane for flat image mascots (preserves 2D design)
+        # This works much better than wrapping around a sphere!
+        bpy.ops.mesh.primitive_plane_add(size=2, location=(0, 0, 1))
         mascot = bpy.context.object
         mascot.name = "Mascot"
 
-        # Increase mesh resolution for better material detail
+        # Rotate plane to face camera (90 degrees around X axis)
+        mascot.rotation_euler[0] = 1.5708  # 90 degrees in radians
+
+        # Scale slightly to match expected size
+        mascot.scale = (1.2, 1.2, 1.2)
+
+        # Smooth shading for better appearance
         bpy.ops.object.shade_smooth()
 
+        print("  Using billboard plane (preserves flat design)")
+
         # Create production-quality PBR material
         mat = bpy.data.materials.new(name="MascotMaterial_PBR")
         mat.use_nodes = True
+        mat.blend_method = 'BLEND'  # Enable alpha transparency
+        mat.shadow_method = 'CLIP'  # Proper shadows with transparency
+        mat.use_backface_culling = False  # Render both sides
         nodes = mat.node_tree.nodes
         links = mat.node_tree.links
         mascot.data.materials.append(mat)
@@ -729,22 +740,28 @@ def setup_render_settings(self):
 
         video_config = self.config.get('video', {})
 
-        # Render engine
-        engine = video_config.get('render_engine', 'EEVEE')
+        # Render engine - normalize config names to Blender names
+        engine_config = video_config.get('render_engine', 'EEVEE')
+        engine_map = {
+            'EEVEE': 'BLENDER_EEVEE',
+            'BLENDER_EEVEE': 'BLENDER_EEVEE',
+            'CYCLES': 'CYCLES'
+        }
+        engine = engine_map.get(engine_config, 'BLENDER_EEVEE')
         self.scene.render.engine = engine
         print(f"  Engine: {engine}")
 
         # Samples
         samples = video_config.get('samples', 128)
-        if engine == 'EEVEE':
+        if engine_config == 'EEVEE' or engine == 'BLENDER_EEVEE':
             self.scene.eevee.taa_render_samples = samples
             # EEVEE quality settings
             self.scene.eevee.use_gtao = True  # Ambient occlusion
             self.scene.eevee.use_bloom = True  # Bloom
             self.scene.eevee.use_ssr = True  # Screen space reflections
             self.scene.eevee.use_ssr_refraction = True
             self.scene.eevee.use_volumetric_shadows = True
-        elif engine == 'CYCLES':
+        elif engine_config == 'CYCLES' or engine == 'CYCLES':
             self.scene.cycles.samples = samples
             # Cycles quality settings
             self.scene.cycles.use_adaptive_sampling = True

demo_reel/config_3d_billboard_test.yaml

@@ -0,0 +1,70 @@
+# Quick test config for 3D billboard mode (24 frames = 1 second)
+inputs:
+  mascot_image: demo_reel/assets/demo_fox.png
+  song_file: demo_reel/assets/demo_song.wav
+  lyrics_file: demo_reel/assets/demo_lyrics.txt
+output:
+  output_dir: demo_reel/3d_billboard_test
+  video_name: 3d_billboard_test.mp4
+  frames_dir: demo_reel/3d_billboard_test/frames
+  prep_json: demo_reel/3d_billboard_test/prep_data.json
+video:
+  duration: 1  # Just 1 second for quick test
+  resolution: [720, 480]  # Smaller for speed
+  fps: 24
+  render_engine: EEVEE
+  samples: 32  # Lower samples for speed
+  codec: libx264
+  quality: high
+style:
+  lighting: jazzy
+  mascot: fox
+  stage: true  # Enable stage floor
+  colors:
+    primary: [0.95, 0.4, 0.2]  # Orange
+    secondary: [0.2, 0.6, 0.9]  # Blue
+    accent: [0.95, 0.85, 0.3]  # Yellow
+  background: gradient
+animation:
+  mode: 3d  # 3D mode with billboard plane!
+  enable_lipsync: true
+  enable_gestures: true
+  enable_lyrics: true
+  enable_effects: true
+  gesture_intensity: 0.8
+  lyrics_style: bounce
+effects:
+  lights:
+    spotlight:
+      enabled: true
+      intensity: 800
+      color: [1.0, 0.95, 0.9]
+    flashes:
+      enabled: true
+      intensity_range: [10, 20]
+      random_colors: true
+# Basic PBR materials (not full production to keep it fast)
+materials:
+  mascot:
+    type: pbr
+    roughness: 0.3
+    metallic: 0.0
+    specular: 0.5
+  stage:
+    type: pbr
+    color: [0.15, 0.15, 0.18]
+    roughness: 0.7
+    metallic: 0.0
+rhubarb:
+  executable_path: null
+  use_mock_fallback: true
+advanced:
+  preview_mode: false
+  preview_scale: 1.0
+  keep_intermediate: true
+  verbose: true
+  threads: null
+blender:
+  executable_path: null
+  background: true
+  script_path: blender_script.py

demo_reel/config_hybrid_test.yaml

@@ -0,0 +1,67 @@
+# Quick test config for hybrid mode (24 frames = 1 second)
+gp_style:
+  stroke_thickness: 4
+  ink_type: sketchy
+  enable_wobble: true
+  wobble_intensity: 0.6
+inputs:
+  mascot_image: demo_reel/assets/demo_fox.png
+  song_file: demo_reel/assets/demo_song.wav
+  lyrics_file: demo_reel/assets/demo_lyrics.txt
+output:
+  output_dir: demo_reel/hybrid_test
+  video_name: hybrid_test.mp4
+  frames_dir: demo_reel/hybrid_test/frames
+  prep_json: demo_reel/hybrid_test/prep_data.json
+video:
+  duration: 1  # Just 1 second for quick test
+  resolution: [720, 480]  # Smaller for speed
+  fps: 24
+  render_engine: EEVEE
+  samples: 32  # Lower samples for speed
+  codec: libx264
+  quality: high
+style:
+  lighting: jazzy
+  mascot: fox
+  colors:
+    primary: [0.9, 0.2, 0.7]
+    secondary: [0.2, 0.9, 0.9]
+    accent: [0.9, 0.9, 0.2]
+  background: gradient
+animation:
+  mode: hybrid  # 2D mascot on 3D stage!
+  enable_lipsync: true
+  enable_gestures: true
+  enable_lyrics: true
+  enable_effects: true
+  gesture_intensity: 0.8
+  lyrics_style: bounce
+effects:
+  fog:
+    enabled: true
+    density: 0.03
+  particles:
+    enabled: false  # Disable for speed
+  lights:
+    spotlight:
+      enabled: true
+      intensity: 800
+      color: [1.0, 0.95, 0.9]
+    flashes:
+      enabled: true
+      intensity_range: [10, 20]
+      random_colors: true
+rhubarb:
+  executable_path: null
+  use_mock_fallback: true
+advanced:
+  preview_mode: false
+  preview_scale: 1.0
+  keep_intermediate: true
+  verbose: true
+  threads: null
+blender:
+  executable_path: null
+  background: true
+  script_path: blender_script.py