Update app.py

app.py

@@ -6,6 +6,7 @@ import requests
 import base64
 import sys
 import shutil
+import re
 from streamlit_ace import st_ace
 
 st.set_page_config(page_title="Blender 3D Viewer", layout="wide")
@@ -34,6 +35,37 @@ def find_blender():
     
     return None
 
+# Preprocess script to ensure it has necessary imports and path handling
+def preprocess_script(script_text, tmp_dir):
+    # Check if 'import os' exists in the script
+    if 'import os' not in script_text:
+        script_text = 'import os\n' + script_text
+    
+    # Check if 'import math' exists in the script (commonly needed)
+    if 'import math' not in script_text and 'math.' in script_text:
+        script_text = 'import math\n' + script_text
+    
+    # Check if script already has file saving code
+    if 'bpy.ops.wm.save_as_mainfile' not in script_text:
+        # Add file saving code at the end
+        script_text += f'''
+
+# Save the .blend file
+output_dir = os.environ.get('BLENDER_OUTPUT_DIR', os.getcwd())
+blend_file_path = os.path.join(output_dir, "scene.blend")
+bpy.ops.wm.save_as_mainfile(filepath=blend_file_path)
+print(f"Saved blend file to: {{blend_file_path}}")
+'''
+    else:
+        # Make sure existing save code uses absolute paths correctly
+        script_text = re.sub(
+            r'bpy\.ops\.wm\.save_as_mainfile\s*\(\s*filepath\s*=\s*["\']([^"\']+)["\']',
+            'bpy.ops.wm.save_as_mainfile(filepath=os.path.join(os.environ.get("BLENDER_OUTPUT_DIR", os.getcwd()), "scene.blend")',
+            script_text
+        )
+    
+    return script_text
+
 # Check if Blender is available at startup
 blender_path = find_blender()
 if not blender_path:
@@ -50,7 +82,6 @@ DEFAULT_TEXTURE_URLS = [
 # Sidebar: Blender script editor with example script
 default_script = """
 import bpy
-import os
 import math
 
 # Clear the scene
@@ -126,17 +157,116 @@ light.data.energy = 2.0
 bpy.context.scene.render.engine = 'CYCLES'
 bpy.context.scene.cycles.device = 'CPU'
 bpy.context.scene.render.film_transparent = True
-
-# Save the .blend file using an absolute path
-output_dir = os.environ.get('BLENDER_OUTPUT_DIR', os.getcwd())
-blend_file_path = os.path.join(output_dir, "scene.blend")
-bpy.ops.wm.save_as_mainfile(filepath=blend_file_path)
 """
 
+# Sidebar: Blender script examples
+script_examples = {
+    "Earth with Texture": default_script,
+    "Solar System": """import bpy
+import math
+
+# Clear existing objects
+bpy.ops.object.select_all(action='SELECT')
+bpy.ops.object.delete(use_global=False)
+
+# Function to create a sphere (planet or sun)
+def create_celestial_body(name, radius, location, color):
+    # Create mesh sphere
+    bpy.ops.mesh.primitive_uv_sphere_add(radius=radius, location=location)
+    obj = bpy.context.active_object
+    obj.name = name
+    
+    # Create material
+    mat = bpy.data.materials.new(name + "_Material")
+    mat.use_nodes = True
+    bsdf = mat.node_tree.nodes.get('Principled BSDF')
+    bsdf.inputs['Base Color'].default_value = (*color, 1)
+    bsdf.inputs['Roughness'].default_value = 0.5
+    
+    # Assign material
+    if obj.data.materials:
+        obj.data.materials[0] = mat
+    else:
+        obj.data.materials.append(mat)
+    return obj
+
+# Create the Sun (yellow)
+sun = create_celestial_body('Sun', radius=2, location=(0,0,0), color=(1.0, 1.0, 0.0))
+
+# Create an empty at origin to parent planets for orbiting
+def create_orbit_empty(name):
+    bpy.ops.object.empty_add(type='PLAIN_AXES', location=(0,0,0))
+    empty = bpy.context.active_object
+    empty.name = name
+    return empty
+
+# Planet definitions: name, radius, distance from sun, color, orbital period in frames
+planets = [
+    ('Mercury', 0.3, 4, (0.8, 0.5, 0.2), 88),
+    ('Venus',   0.5, 6, (1.0, 0.8, 0.0), 224),
+    ('Earth',   0.5, 8, (0.2, 0.4, 1.0), 365),
+    ('Mars',    0.4, 10,(1.0, 0.3, 0.2), 687)
+]
+
+for name, radius, distance, color, period in planets:
+    # Create orbit controller
+    orbit_empty = create_orbit_empty(name + '_Orbit')
+    
+    # Create planet as child of orbit empty
+    planet = create_celestial_body(name, radius, location=(distance, 0, 0), color=color)
+    planet.parent = orbit_empty
+    
+    # Animate the orbit: rotate empty around Z
+    orbit_empty.rotation_euler = (0, 0, 0)
+    orbit_empty.keyframe_insert(data_path='rotation_euler', frame=1, index=2)
+    orbit_empty.rotation_euler = (0, 0, math.radians(360))
+    orbit_empty.keyframe_insert(data_path='rotation_euler', frame=period, index=2)
+    
+    # Set linear interpolation for smooth constant motion
+    action = orbit_empty.animation_data.action
+    fcurve = action.fcurves.find('rotation_euler', index=2)
+    if fcurve:
+        for kp in fcurve.keyframe_points:
+            kp.interpolation = 'LINEAR'
+
+# Set scene frames
+bpy.context.scene.frame_start = 1
+bpy.context.scene.frame_end = 687  # Use Mars' period as the end frame
+
+# Add simple starfield as world background
+world = bpy.context.scene.world
+world.use_nodes = True
+bg = world.node_tree.nodes['Background']
+bg.inputs['Color'].default_value = (0, 0, 0, 1)
+
+# Set up a better camera view
+bpy.ops.object.camera_add(location=(0, -20, 15))
+camera = bpy.context.active_object
+camera.rotation_euler = (math.radians(55), 0, 0)
+bpy.context.scene.camera = camera
+
+# Add a sun light
+bpy.ops.object.light_add(type='SUN', location=(10, -10, 10))
+sun_light = bpy.context.active_object
+sun_light.data.energy = 5.0
+
+# Set render settings
+bpy.context.scene.render.engine = 'CYCLES'
+bpy.context.scene.cycles.device = 'CPU'
+
+print('Solar system animation setup complete.')"""
+}
+
+# Add example selector
+selected_example = st.sidebar.selectbox(
+    "Load example script:",
+    options=list(script_examples.keys())
+)
+
 # Sidebar: Blender script editor
 st.sidebar.header("Blender Python Script")
 script_text = st_ace(
-    value=default_script,
+    value=script_examples[selected_example],
     placeholder="Paste your Blender Python script here...",
     language="python",
     theme="monokai",
@@ -172,10 +302,11 @@ if st.sidebar.button("Run & Export GLB"):
         # Use a more robust temporary directory approach
         tmp_dir = tempfile.mkdtemp(prefix="blender_app_")
         try:
-            # 1) Save user script
+            # 1) Preprocess and save user script
+            processed_script = preprocess_script(script_text, tmp_dir)
             script_path = os.path.join(tmp_dir, "user_script.py")
             with open(script_path, "w") as f:
-                f.write(script_text)
+                f.write(processed_script)
 
             # 2) Collect textures
             texture_paths = []
@@ -367,14 +498,8 @@ with st.expander("About this app"):
     - Generate and visualize 3D models with animations
     - Download the results as GLB files for use in other applications
     
-    The example script creates a rotating Earth with the uploaded texture.
-    
-    ### Troubleshooting
-    
-    - If you encounter errors, check the console output for details
-    - Make sure your script correctly saves files using absolute paths
-    - For complex models, allow more time for processing
-    - If the app doesn't work at all, the Hugging Face Space might need proper Blender installation
+    The app automatically adds necessary imports (`import os`) and file saving code to your scripts,
+    so you can focus on creating 3D content without worrying about environment details.
     """)
     
 with st.expander("Script Tips"):
@@ -390,14 +515,15 @@ with st.expander("Script Tips"):
         image = bpy.data.images.load(texture_paths[0])
     ```
     
-    2. **Saving files**: Always use absolute paths with the environment variable
+    2. **You don't need to add file saving code** - the app automatically adds it
+    
+    3. **Animations**: Make sure to set keyframes if you want your model to animate:
     
     ```python
-    # Example code to save your blend file
-    output_dir = os.environ.get('BLENDER_OUTPUT_DIR', os.getcwd())
-    blend_file_path = os.path.join(output_dir, "scene.blend")
-    bpy.ops.wm.save_as_mainfile(filepath=blend_file_path)
+    # Example animation (rotate object 360 degrees over 250 frames)
+    obj.rotation_euler = (0, 0, 0)
+    obj.keyframe_insert(data_path="rotation_euler", frame=1)
+    obj.rotation_euler = (0, 0, math.radians(360))
+    obj.keyframe_insert(data_path="rotation_euler", frame=250)
     ```
-    
-    3. **Animations**: Make sure to set keyframes if you want your model to animate
     """)