Update app.py

app.py

@@ -1,7 +1,6 @@
 """
-Gradio app: .vox → .glb conversion + built-in Model3D viewer.
-
-Now using safer voxel-to-mesh conversion via occupancy grid + marching cubes.
+Gradio app: robust .vox → .glb conversion + built-in Model3D viewer.
+Handles small and large voxel files, centers and colors mesh to avoid 'paper icon'.
 """
 
 import gradio as gr
@@ -15,22 +14,32 @@ from pyvox.parser import VoxParser
 def vox_to_glb(file_path):
     vox = VoxParser(file_path).parse()
     model = vox.models[0]
-    size_x, size_y, size_z = model.size.x, model.size.y, model.size.z
     voxels = model.voxels
+    size_x, size_y, size_z = model.size.x, model.size.y, model.size.z
 
     if not voxels:
-        raise ValueError("No voxels found in file")
+        raise ValueError("No voxels found")
 
-    # Create occupancy grid
-    grid = np.zeros((size_x, size_y, size_z), dtype=bool)
-    for v in voxels:
-        grid[v.x, v.y, v.z] = True
+    # Small grid: cube per voxel, Large grid: marching cubes
+    if max(size_x, size_y, size_z) <= 16:
+        cubes = []
+        for v in voxels:
+            cube = trimesh.creation.box(extents=(1,1,1))
+            cube.apply_translation([v.x, v.y, v.z])
+            cubes.append(cube)
+        mesh = trimesh.util.concatenate(cubes)
+    else:
+        grid = np.zeros((size_x, size_y, size_z), dtype=bool)
+        for v in voxels:
+            grid[v.x, v.y, v.z] = True
+        mesh = trimesh.voxel.ops.matrix_to_marching_cubes(grid)
 
-    # Convert occupancy grid to mesh
-    mesh = trimesh.voxel.ops.matrix_to_marching_cubes(grid)
+    # Center mesh, scale, add color
+    mesh.apply_translation(-mesh.centroid)
+    mesh.apply_scale(1.0)
+    mesh.visual.vertex_colors = [200, 100, 50, 255]
 
-    # Export to temporary glb
-    tmp = tempfile.NamedTemporaryFile(suffix='.glb', delete=False)
+    tmp = tempfile.NamedTemporaryFile(suffix=".glb", delete=False)
     mesh.export(tmp.name)
     return tmp.name