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HartOMat/tools/restore_sharp_marks.py

103 lines
4.3 KiB
Python

"""Blender companion script: restore sharp + seam edge marks after importing a production GLB.
After importing a HartOMat production GLB in Blender, run this script once via
the Scripting workspace (Text Editor → Run Script). It reads the sharp angle AND the
OCC B-rep sharp edge pairs baked into the GLB at export time, and re-applies
mark_sharp() + mark_seam() on every mesh object.
The GLB visual shading already encodes the sharp edges via vertex splits (normals).
This script restores the blue sharp-crease and red seam markers in Edit Mode for
further editing in Blender — including for UV unwrapping.
Usage:
1. File → Import → glTF 2.0 (.glb) — open your production GLB
2. Open the Scripting workspace
3. Open this file (Text Editor → Open → restore_sharp_marks.py)
4. Click Run Script
"""
import bpy
import math
import bmesh
import mathutils
mesh_objects = [o for o in bpy.data.objects if o.type == "MESH"]
if not mesh_objects:
print("No mesh objects found in scene.")
else:
# --- Pass 1: dihedral-angle-based sharp/seam marks ---
angle_deg = bpy.context.scene.get("hartomat_sharp_angle_deg", 30.0)
smooth_rad = math.radians(float(angle_deg))
total_sharp = 0
bpy.ops.object.select_all(action="DESELECT")
for obj in mesh_objects:
bpy.context.view_layer.objects.active = obj
obj.select_set(True)
bpy.ops.object.mode_set(mode="OBJECT")
for poly in obj.data.polygons:
poly.use_smooth = True
bpy.ops.object.mode_set(mode="EDIT")
bpy.ops.mesh.select_all(action="DESELECT")
bpy.ops.mesh.edges_select_sharp(sharpness=smooth_rad)
bpy.ops.mesh.mark_sharp()
bpy.ops.mesh.mark_seam()
bpy.ops.object.mode_set(mode="OBJECT")
total_sharp += sum(1 for e in obj.data.edges if e.use_edge_sharp)
obj.select_set(False)
print(f"Pass 1 (dihedral {angle_deg}°): {total_sharp} sharp/seam edges across {len(mesh_objects)} objects.")
# --- Pass 2: OCC B-rep sharp edges from GLB extras ---
# The production GLB embeds hartomat_sharp_edge_pairs (OCC B-rep topology,
# dense curve samples at 0.3mm) in scenes[0].extras, which Blender maps to
# scene custom properties on import. These cover geometrically sharp edges
# that the dihedral-angle pass misses due to tessellation noise.
#
# Coordinate convention (mirrors export_gltf.py _apply_sharp_edges_from_occ):
# OCC STEP space (Z-up, mm) → Blender (Z-up, m):
# Blender(X, Y, Z) = OCC(X*0.001, -Z*0.001, Y*0.001)
occ_pairs = bpy.context.scene.get("hartomat_sharp_edge_pairs") or []
if occ_pairs:
print(f"Pass 2 (OCC B-rep): applying {len(occ_pairs)} sharp edge segment pairs...")
SCALE = 0.001 # OCC mm → Blender m
TOL = 0.0005 # 0.5 mm tolerance in metres
marked_total = 0
for obj in mesh_objects:
bm_obj = bmesh.new()
bm_obj.from_mesh(obj.data)
bm_obj.verts.ensure_lookup_table()
bm_obj.edges.ensure_lookup_table()
world_mat = obj.matrix_world
kd = mathutils.kdtree.KDTree(len(bm_obj.verts))
for v in bm_obj.verts:
kd.insert(world_mat @ v.co, v.index)
kd.balance()
marked = 0
for pair in occ_pairs:
v0_bl = mathutils.Vector((pair[0][0] * SCALE, -pair[0][2] * SCALE, pair[0][1] * SCALE))
v1_bl = mathutils.Vector((pair[1][0] * SCALE, -pair[1][2] * SCALE, pair[1][1] * SCALE))
_co0, idx0, dist0 = kd.find(v0_bl)
_co1, idx1, dist1 = kd.find(v1_bl)
if dist0 > TOL or dist1 > TOL:
continue
if idx0 == idx1:
continue
bv0, bv1 = bm_obj.verts[idx0], bm_obj.verts[idx1]
edge = bm_obj.edges.get((bv0, bv1)) or bm_obj.edges.get((bv1, bv0))
if edge is not None:
edge.smooth = False
edge.seam = True
marked += 1
bm_obj.to_mesh(obj.data)
bm_obj.free()
marked_total += marked
print(f"Pass 2 (OCC B-rep): {marked_total} additional edges marked across {len(mesh_objects)} objects.")
else:
print("Pass 2 (OCC B-rep): no hartomat_sharp_edge_pairs in GLB extras — skipped.")