safety

create_glb.py

@@ -0,0 +1,71 @@
+#!/usr/bin/env python3
+# create_glb.py — Blender headless STL -> GLB
+#
+# Example:
+#   blender-bin-5.0.0 --background --python create_glb.py -- input.stl [output.glb]
+
+import bpy
+import sys
+import os
+from mathutils import Vector
+
+def die(msg, rc=2):
+    print(f"ERROR: {msg}")
+    raise SystemExit(rc)
+
+# args after "--"
+argv = sys.argv
+argv = argv[argv.index("--") + 1:] if "--" in argv else []
+
+if len(argv) == 1:
+    inp = argv[0]
+    base, _ = os.path.splitext(inp)
+    outp = base + ".glb"
+elif len(argv) >= 2:
+    inp, outp = argv[0], argv[1]
+else:
+    die("USAGE: blender --background --python create_glb.py -- input.stl [output.glb]")
+
+if not os.path.exists(inp):
+    die(f"Input not found: {inp}")
+
+# Empty scene
+bpy.ops.wm.read_factory_settings(use_empty=True)
+
+# Import STL (Blender 4/5 operator)
+res = bpy.ops.wm.stl_import(filepath=inp)
+if 'FINISHED' not in res:
+    die(f"STL import failed for: {inp}")
+
+# Gather imported mesh objects
+objs = [o for o in bpy.context.scene.objects if o.type == 'MESH']
+if not objs:
+    die("No mesh objects after import (unexpected)")
+
+# Compute combined bounding box center in world space
+min_v = Vector(( 1e30,  1e30,  1e30))
+max_v = Vector((-1e30, -1e30, -1e30))
+
+for o in objs:
+    # object bound_box is in local coords; transform to world
+    for corner in o.bound_box:
+        v = o.matrix_world @ Vector(corner)
+        min_v.x = min(min_v.x, v.x); min_v.y = min(min_v.y, v.y); min_v.z = min(min_v.z, v.z)
+        max_v.x = max(max_v.x, v.x); max_v.y = max(max_v.y, v.y); max_v.z = max(max_v.z, v.z)
+
+center = (min_v + max_v) * 0.5
+
+# Translate all meshes so center is at origin
+for o in objs:
+    o.location -= center
+
+# Export GLB
+res = bpy.ops.export_scene.gltf(
+    filepath=outp,
+    export_format='GLB',
+    export_apply=True,
+)
+if 'FINISHED' not in res:
+    die(f"GLB export failed: {outp}")
+
+print(f"Wrote: {outp}")