diff options
author | Campbell Barton <ideasman42@gmail.com> | 2011-07-13 11:50:21 +0400 |
---|---|---|
committer | Campbell Barton <ideasman42@gmail.com> | 2011-07-13 11:50:21 +0400 |
commit | b0ffa7fc580c49a2c50377cbe19c76279d303dfb (patch) | |
tree | cdf84b33b7ca5c8b5766e2f307c521f9fb615f7b /release/scripts | |
parent | 44e45e54c51e2f54c89b173e8844a99ce7f5de75 (diff) |
patch [#27950] Patch to add the ability to generate random points on mesh faces
from Andrew Hale (trumanblending)
Diffstat (limited to 'release/scripts')
-rw-r--r-- | release/scripts/modules/bpy_extras/mesh_utils.py | 73 |
1 files changed, 71 insertions, 2 deletions
diff --git a/release/scripts/modules/bpy_extras/mesh_utils.py b/release/scripts/modules/bpy_extras/mesh_utils.py index 34925ccb5e9..c42d3d0236a 100644 --- a/release/scripts/modules/bpy_extras/mesh_utils.py +++ b/release/scripts/modules/bpy_extras/mesh_utils.py @@ -16,7 +16,7 @@ # # ##### END GPL LICENSE BLOCK ##### -# <pep8 compliant> +# <pep8-80 compliant> __all__ = ( "mesh_linked_faces", @@ -25,6 +25,7 @@ __all__ = ( "edge_loops_from_faces", "edge_loops_from_edges", "ngon_tesselate", + "face_random_points", ) @@ -67,7 +68,8 @@ def mesh_linked_faces(mesh): if mapped_index != nxt_mapped_index: ok = True - # Assign mapping to this group so they all map to this group + # Assign mapping to this group so they + # all map to this group for grp_f in face_groups[nxt_mapped_index]: face_mapping[grp_f.index] = mapped_index @@ -433,3 +435,70 @@ def ngon_tesselate(from_data, indices, fix_loops=True): fill[i] = tuple([ii for ii in reversed(fi)]) return fill + + +def face_random_points(num_points, faces): + """ + Generates a list of random points over mesh faces. + + :arg num_points: the number of random points to generate on each face. + :type int: + :arg faces: list of the faces to generate points on. + :type faces: :class:`MeshFaces`, sequence + :return: list of random points over all faces. + :rtype: list + """ + + from random import random + from mathutils.geometry import area_tri + + # Split all quads into 2 tris, tris remain unchanged + tri_faces = [] + for f in faces: + tris = [] + verts = f.id_data.vertices + fv = f.vertices[:] + tris.append((verts[fv[0]].co, + verts[fv[1]].co, + verts[fv[2]].co, + )) + if len(fv) == 4: + tris.append((verts[fv[0]].co, + verts[fv[3]].co, + verts[fv[2]].co, + )) + tri_faces.append(tris) + + # For each face, generate the required number of random points + sampled_points = [None] * (num_points * len(faces)) + for i, tf in enumerate(tri_faces): + for k in range(num_points): + # If this is a quad, we need to weight its 2 tris by their area + if len(tf) != 1: + area1 = area_tri(*tf[0]) + area2 = area_tri(*tf[1]) + area_tot = area1 + area2 + + area1 = area1 / area_tot + area2 = area2 / area_tot + + vecs = tf[0 if (random() < area1) else 1] + else: + vecs = tf[0] + + u1 = random() + u2 = random() + u_tot = u1 + u2 + + if u_tot > 1: + u1 = 1.0 - u1 + u2 = 1.0 - u2 + + side1 = vecs[1] - vecs[0] + side2 = vecs[2] - vecs[0] + + p = vecs[0] + u1 * side1 + u2 * side2 + + sampled_points[num_points * i + k] = p + + return sampled_points |