Extract Point Cloud from Blender mesh

I had a chance to make a sample point cloud which is mathematically generated and perfectly designed to compare alignment performance. I thought it’s quite obvious to get point cloud but wasn’t on blender. Here’s the python script how to export .ply file from Blender mesh.

Reference : How can I create a point cloud from the surfaces of a model?

I referenced this article and modified the code to make point on triangle’s edges, not on middle of triangles.

import bpy
import bmesh

# ---------------------------------------------------------------------
# create vertices
# ---------------------------------------------------------------------
# verts: list of position coords - [(-1.0, 1.0, 0.0), (-1.0, -1.0, 0.0)]
# returns the new object

def create_Vertices (name, verts):
    me = bpy.data.meshes.new(name+'Mesh')
    ob = bpy.data.objects.new(name, me)
    ob.show_name = True
    bpy.context.scene.objects.link(ob)
    me.from_pydata(verts, [], [])
    me.update()
    return ob

# -----------------------------------------------------------------------
# get face positions from a mesh object
# -----------------------------------------------------------------------
# returns: absolute face center positions

def face_Positions_From_Object(meshObj):
    me = meshObj.data
    bm = bmesh.new()
    bm.from_mesh(me)
    bmFaces = set()


    for face in bm.faces:
        v = meshObj.matrix_world * face.verts[0].co
        v.freeze()
        bmFaces.add(v)
        v = meshObj.matrix_world * face.verts[1].co
        v.freeze()
        bmFaces.add(v)
        v = meshObj.matrix_world * face.verts[2].co
        v.freeze()
        bmFaces.add(v)

    return bmFaces

# -----------------------------------------------------------------------
# do it
# -----------------------------------------------------------------------

obj = bpy.context.active_object
facePosOfObj = face_Positions_From_Object(obj)
pointCloud = create_Vertices(obj.name + '_pointcloud', facePosOfObj)

On this section,

v = meshObj.matrix_world * face.verts[0].co
v.freeze()
bmFaces.add(v)

It will multiply mesh’s world coordinate and triangle’s 1st edge’s coordinate.

Then call freeze() to make vector immutable. mathutils.Vector.freeze

And put it into Set. Then there won’t be duplicated verticies and only all of edges coordinates.

Happy 3D hacking :)