98 lines
3.4 KiB
Python
98 lines
3.4 KiB
Python
from collections import defaultdict
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from surf.geometry import PolygonMesh, centroid
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def refine(mesh):
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new_vertices = list(mesh.vertices)
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f_vert_offset = len(new_vertices)
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edge_vids_for = defaultdict(list)
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face_ids_for_v = defaultdict(list)
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# TODO: not completely populated yet:
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new_edges = list(mesh.edges)
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# TODO: must be populated:
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new_faces = []
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# For each face, add a face point
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for cur_face_id, cur_face in enumerate(mesh.faces):
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# Set each face point to be the centroid of all original points for the
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# respective face.
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# here we have already created a list that is a copy of the original
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# verts. we append the new face points to that same list, and simply
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# keep track of offsets into the new vert list ... see e_vert_offset
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# below
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new_face_point = mesh.centroid(cur_face)
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new_vertices.append(new_face_point)
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for i in cur_face:
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face_ids_for_v[i].append(cur_face_id)
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e_vert_offset = len(new_vertices)
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# For each edge, add an edge point.
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for cur_edge_id, cur_edge in enumerate(mesh.edges):
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# make mapping from edge -> new_face_vert for later
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face_ids_for_edge = mesh.faces_for_edge[cur_edge_id]
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for fid in face_ids_for_edge:
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edge_vids_for[fid].append(cur_edge_id)
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tmp_verts = []
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# Set each edge point to be the average of the two neighbouring, (very
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# recently calculated) face points ...
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tmp_verts.extend([new_vertices[f + f_vert_offset] for f in face_ids_for_edge])
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# ... and its two original endpoints.
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tmp_verts.extend([mesh.vertices[vid] for vid in cur_edge])
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# centroid == average
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new_vertices.append(centroid(tmp_verts))
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# For each face point, add an edge for every edge of the face, connecting
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# the face point to each edge point for the face.
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for trunc_vid in xrange(len(new_vertices[f_vert_offset:e_vert_offset])):
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overall_vid = f_vert_offset + trunc_vid
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for edge_vid in edge_vids_for[trunc_vid]:
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new_edges.append([edge_vid, overall_vid])
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# v_vert_offset = len(new_vertices)
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# For each original point P
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for new_vid in xrange(f_vert_offset):
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# take the average F of all n face points for faces touching P ...
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new_face_ids = face_ids_for_v[new_vid]
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F_verts = []
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for fid in new_face_ids:
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F_verts.append(new_vertices[f_vert_offset + fid])
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F = centroid(F_verts)
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# and take the average R of all n edge midpoints for edges touching P
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# wiki is wrong ... it should be the edge points, not midpoints ...
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edges = [mesh.edges[eid] for eid in mesh.edges_for_vert[new_vid]]
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e_verts = []
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for edge in edges:
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e_verts.extend([mesh.vertices[vid] for vid in edge])
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R = centroid(e_verts)
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# where each edge midpoint is the average of its two endpoint vertices.
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# Move each original point to the point (or add it to new_verts)
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new_vertex_point = (F + 2 * R + (len(edges) - 3) * new_vertices[new_vid]) / len(edges)
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new_vertices.append(new_vertex_point)
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return PolygonMesh(vertices=new_vertices, edges=new_edges, faces=new_faces)
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if __name__ == '__main__':
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import json
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from surf.subd.cc import refine
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cube = json.load(open('blender/samples/cube.json', 'r'))
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p = PolygonMesh(**cube)
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q = refine(p)
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print q
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