建立方向盘项目初始版本

scripts/build_pcd50_print_plate.py

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+"""Place existing PCD50 STL meshes on two print plates without changing shapes.
+
+Run with FreeCAD's Python, for example:
+    & 'C:\\Users\\billy\\scoop\\apps\\freecad\\current\\bin\\python.exe' scripts/build_pcd50_print_plate.py
+
+The main plate is one bracket and four 0.5 mm shims. The second plate holds
+four optional 1 mm shims.  Output is independent of the input files.
+"""
+from pathlib import Path
+import json
+import itertools
+import math
+import FreeCAD as App
+import Mesh
+
+ROOT = Path(__file__).resolve().parent.parent
+SOURCE = ROOT / 'models' / 'pcd50_open_pillar_v1'
+OUT = ROOT / 'models' / 'pcd50_print_plate'
+OUT.mkdir(parents=True, exist_ok=True)
+V = App.Vector
+
+def load(name):
+    mesh = Mesh.Mesh(str(SOURCE / name))
+    if len(mesh.getSeparateComponents()) != 1 or not mesh.isSolid():
+        raise RuntimeError('Input is not one closed component: ' + name)
+    return mesh
+
+bracket = load('EncoderBracket.stl')
+shim05 = load('Shim05.stl')
+shim10 = load('Shim10.stl')
+
+# X positions are chosen to give at least 8 mm between the shims' actual
+# bounding boxes. The 49 mm bracket sits 8 mm above their actual Y maximum.
+# Every placement uses the original tessellation; no rotations or rescaling.
+row = [(6 + 20*i, 6.0) for i in range(4)]
+bracket_pos = (35.77, 44.5)
+
+def moved(mesh, x, y):
+    result = mesh.copy()
+    result.translate(x, y, -mesh.BoundBox.ZMin)
+    return result
+
+def bounds(m):
+    b = m.BoundBox
+    return [b.XMin, b.XMax, b.YMin, b.YMax, b.ZMin, b.ZMax]
+
+def distance_xy(a, b):
+    a, b = a.BoundBox, b.BoundBox
+    dx = max(a.XMin - b.XMax, b.XMin - a.XMax, 0.0)
+    dy = max(a.YMin - b.YMax, b.YMin - a.YMax, 0.0)
+    return math.hypot(dx, dy)
+
+def equivalent(a, b):
+    """Compare vertices and facet topology after removing translation.
+
+    Float STL coordinates round slightly when translated/reloaded. A small
+    tolerance is therefore used rather than comparing quantized text.
+    """
+    if a.CountFacets != b.CountFacets:
+        return False
+    pa, fa = a.Topology; pb, fb = b.Topology
+    if len(pa) != len(pb):
+        return False
+    ba, bb = a.BoundBox, b.BoundBox
+    def norm(p, box): return (p.x-box.XMin,p.y-box.YMin,p.z-box.ZMin)
+    qa=[norm(p,ba) for p in pa]; qb=[norm(p,bb) for p in pb]
+    tol=0.0001
+    def key(v): return tuple(math.floor(x/tol) for x in v)
+    bins={}
+    for i,v in enumerate(qa):bins.setdefault(key(v),[]).append(i)
+    matches=[]
+    for v in qb:
+        k=key(v); candidates=[]
+        for offset in itertools.product((-1,0,1),repeat=3):
+            for i in bins.get(tuple(k[j]+offset[j] for j in range(3)),[]):
+                dist=max(abs(v[j]-qa[i][j]) for j in range(3))
+                if dist<tol:candidates.append((dist,i))
+        if not candidates:return False
+        matches.append(min(candidates)[1])
+    if len(set(matches)) != len(qa):return False
+    af=sorted(tuple(sorted(tri)) for tri in fa)
+    bf=sorted(tuple(sorted(matches[i] for i in tri)) for tri in fb)
+    return af==bf
+
+def plate(stem, specs):
+    document = App.newDocument(stem)
+    meshes = []
+    combined = Mesh.Mesh()
+    info = []
+    for name, original, x, y in specs:
+        m = moved(original, x, y)
+        if not m.isSolid() or len(m.getSeparateComponents()) != 1:
+            raise RuntimeError('Invalid input mesh after placement: ' + name)
+        if not equivalent(original, m):
+            raise RuntimeError('Geometry changed during placement: ' + name)
+        obj = document.addObject('Mesh::Feature', name)
+        obj.Label = name
+        obj.Mesh = m
+        combined.addMesh(m)
+        meshes.append(m)
+        info.append({'name':name, 'facets':m.CountFacets,
+                     'volume_mm3':m.Volume, 'bounds_mm':bounds(m)})
+    for i, a in enumerate(meshes):
+        for b in meshes[i+1:]:
+            d=distance_xy(a,b)
+            if d < 8.0:
+                raise RuntimeError('Parts too close: %.6f mm bounding-box distance' % d)
+    min_gap=min(distance_xy(a,b) for i,a in enumerate(meshes) for b in meshes[i+1:])
+    combined.write(str(OUT / (stem+'.stl')))
+    document.recompute()
+    document.saveAs(str(OUT / (stem+'.FCStd')))
+    App.closeDocument(document.Name)
+    reloaded=Mesh.Mesh(str(OUT / (stem+'.stl')))
+    parts=reloaded.getSeparateComponents()
+    if len(parts)!=len(specs) or any(not p.isSolid() for p in parts):
+        raise RuntimeError('Export does not contain the expected closed components')
+    for expected in meshes:
+        candidates=[p for p in parts if abs(p.BoundBox.XMin-expected.BoundBox.XMin)<0.0001
+                    and abs(p.BoundBox.YMin-expected.BoundBox.YMin)<0.0001]
+        if len(candidates)!=1 or not equivalent(expected,candidates[0]):
+            raise RuntimeError('Exported mesh differs from the placed original mesh')
+    if min(p.BoundBox.ZMin for p in parts) < -0.001 or max(abs(p.BoundBox.ZMin) for p in parts) > .001:
+        raise RuntimeError('Parts are not all at Z=0')
+    return {'file':stem+'.stl', 'components':len(parts),
+            'all_closed':True, 'geometry_preserved':True,
+            'minimum_bounding_box_gap_mm':min_gap,
+            'bounds_mm':bounds(reloaded), 'objects':info}
+
+main=[('Bracket',bracket,*bracket_pos)]+[('Shim05_%d'%(i+1),shim05,*xy) for i,xy in enumerate(row)]
+spare=[('Shim10_%d'%(i+1),shim10,*xy) for i,xy in enumerate(row)]
+result={'main':plate('支架和四个0.5mm垫片',main),
+        'spare':plate('四个1mm备用垫片',spare)}
+(OUT/'布局检查.json').write_text(json.dumps(result,ensure_ascii=False,indent=2),encoding='utf-8')
+print(json.dumps(result,ensure_ascii=False,indent=2))