blender-syntax-mesh

Quick Reference

Critical Warnings

NEVER access mesh.vertices, mesh.edges, mesh.polygons, or mesh.loops while in Edit Mode — data is not synchronized. Use bmesh.from_edit_mesh() instead.

NEVER forget mesh.update() after mesh.from_pydata() — normals and derived data will be incorrect.

NEVER forget bm.free() after BMesh operations in Object Mode — causes memory leaks. Exception: edit-mode BMesh from bmesh.from_edit_mesh() must NOT be freed.

NEVER access BMesh elements by index without calling ensure_lookup_table() first — raises IndexError or undefined behavior.

NEVER use mesh.calc_normals() in Blender 4.0+ — removed, normals are computed automatically.

NEVER use mesh.use_auto_smooth or mesh.auto_smooth_angle in Blender 4.1+ — removed, auto-smooth is automatic when custom or sharp normals exist.

NEVER use MeshEdge.bevel_weight, MeshEdge.crease, or MeshVertex.bevel_weight in Blender 4.0+ — replaced by mesh.attributes["bevel_weight_edge"], mesh.attributes["crease_edge"], etc.