110 lines
2.9 KiB
Python
110 lines
2.9 KiB
Python
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# Stage 6h: bi-harmonic membrane over the located flap sphere. Melting (06g) barely dented
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# the fold — layered flaps are locally smooth and resist neighbour-averaging. Replace instead:
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# excise the sphere, solve the rim-anchored membrane (same method that healed the gusset).
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# blender --background --python 06h_flap_membrane.py -- <in.blend> <out.blend> <cx> <cy> <cz> <r>
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import bpy, sys, time
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import numpy as np
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argv = sys.argv[sys.argv.index("--") + 1:]
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BLEND, OUT = argv[0], argv[1]
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CTR = np.array([float(argv[2]), float(argv[3]), float(argv[4])])
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R = float(argv[5])
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t0 = time.time()
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def log(m):
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print(f"[flap {time.time()-t0:6.1f}s] {m}", flush=True)
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bpy.ops.wm.open_mainfile(filepath=BLEND)
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ob = max([o for o in bpy.data.objects if o.type == 'MESH'],
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key=lambda o: len(o.data.vertices))
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me = ob.data
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n_v = len(me.vertices)
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co = np.empty(n_v * 3)
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me.vertices.foreach_get("co", co)
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co = co.reshape(-1, 3)
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n_e = len(me.edges)
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ev0 = np.empty(n_e * 2, dtype=np.int32)
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me.edges.foreach_get("vertices", ev0)
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ev0 = ev0.reshape(-1, 2)
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def grow_edges(mask, rings, ev):
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m = mask.copy()
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for _ in range(rings):
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hit = m[ev[:, 0]] | m[ev[:, 1]]
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m2 = m.copy()
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m2[ev[:, 0]] |= hit
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m2[ev[:, 1]] |= hit
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m = m2
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return m
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sph = np.linalg.norm(co - CTR, axis=1) < R
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free_m = grow_edges(sph, 1, ev0)
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collar = grow_edges(free_m, 2, ev0) & ~free_m
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S = np.nonzero(free_m | collar)[0]
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in_S = np.zeros(n_v, dtype=bool)
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in_S[S] = True
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glb = np.full(n_v, -1, dtype=np.int64)
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glb[S] = np.arange(len(S))
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se = ev0[in_S[ev0].all(axis=1)]
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a_ = glb[se[:, 0]]
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b_ = glb[se[:, 1]]
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deg = np.zeros(len(S))
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np.add.at(deg, a_, 1.0)
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np.add.at(deg, b_, 1.0)
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free = free_m[S]
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log(f"sphere {sph.sum()} -> free {free.sum()}, collar {(~free).sum()}")
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def Ls(X):
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out = deg[:, None] * X
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np.add.at(out, a_, -X[b_])
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np.add.at(out, b_, -X[a_])
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return out
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def A_op(U):
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X = np.zeros((len(S), 3))
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X[free] = U
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return Ls(Ls(X))[free]
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Xc = np.zeros((len(S), 3))
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Xc[~free] = co[S[~free]]
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rhs = -Ls(Ls(Xc))[free]
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U = co[S[free]].copy()
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r = rhs - A_op(U)
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p = r.copy()
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rs = (r * r).sum()
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rs0 = rs
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for it in range(120000):
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Ap = A_op(p)
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al = rs / max((p * Ap).sum(), 1e-30)
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U += al * p
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r -= al * Ap
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rs2 = (r * r).sum()
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if rs2 < 1e-18 or rs2 < rs0 * 1e-14:
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break
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p = r + (rs2 / rs) * p
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rs = rs2
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co_new = co.copy()
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co_new[S[free]] = U
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d = np.linalg.norm(co_new - co, axis=1)
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log(f"membrane: {free.sum()} verts (CG {it} iters, rel {rs2/max(rs0,1e-30):.2e}), "
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f"max move {d.max():.4f}")
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me.vertices.foreach_set("co", co_new.reshape(-1))
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me.update()
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if me.has_custom_normals:
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vn = np.empty(n_v * 3, dtype=np.float32)
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me.vertices.foreach_get("normal", vn)
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me.normals_split_custom_set_from_vertices(vn.reshape(-1, 3))
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bpy.context.preferences.filepaths.save_version = 0 # no .blend1 autosave
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bpy.ops.wm.save_as_mainfile(filepath=OUT)
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log(f"WROTE {OUT}")
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print("FLAP_DONE")
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