Create Point cloud from geometry? - python

I want to make a 3d point cloud from 3d modeling file(dae, obj...) using python code.
like http://upload.wikimedia.org/wikipedia/commons/4/4c/Point_cloud_torus.gif
I have no idea where to begin. Do I need polygon or mesh data or something?
If there were any algorithm for this let me help.
I saw many questions about create mesh from point cloud but it`s very hard to find about this topic.
thanks.

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Feasibility of Visualising Skeleton and Point Cloud Data in Open3D

I need to visualise point-cloud and skeleton data simultaneously - in real time and python. Is this feasible with open3d? Does anyone with point cloud experience have any better library recommendations?

I want to obtain a mesh from a point cloud in python

I have some brain images in a ndarray vector whose size is (25,29,21).
I would like to obtain a mesh from that points cloud but i don't know how.
I need that just to use the zernike moments in this repository:
https://github.com/nipy/mindboggle/blob/bc10812979d42e94b8a01ad8f98b4ceae33169e5/mindboggle/shapes/zernike/zernike.py#L248
Because one of the imput parameters is faces that is a list of lists of 3 integers. Each list contains indices to vertices that form a triangle on a mesh. Does anyone of you know how can i obtain that from my point cloud in ndarray format?
Thanks in advance!
I looked for it on google but i didn't obtain nothing interesting to use. Can someone help me?

Triangle mesh generation of 3D objects using Python

Hey everyone I'm pretty new to graphics programming and I want some guidance or working samples, I want to make any 3D objects but for starters I want to make a 3D cube using triangle mesh with given coordinates via python, and export all the mesh in an .obj file so I can load the mesh and view it in meshlab.
I would really love some guidance on this thanks.
if you are comfortable with meshlab you could find useful pymeshlab
https://pymeshlab.readthedocs.io
Here is a simple tutorial on how to create a mesh from just array of coords and indexes...
https://pymeshlab.readthedocs.io/en/latest/tutorials/import_mesh_from_arrays.html

Is there any tools or algorithms for convert 3D Point Cloud to 2.5D image?

I am looking for an algorithm for convert 3D Point Cloud to Depth Image in Python, especially 3D Face Point Cloud. Can you suggest me some tools or algorithms?
Thanks in advance.

How to analyse/calculate circumference of human body parts from point cloud or 3d objects?

I am using win10, python and c#. I want to calculate circumference of human parts (belly, biceps etc) with using point cloud or 3d scans like .stl .obj .ply. Now I can get the point cloud of human body with kinect v2. I have point cloud of human body, scanned 3d human body in .stl .obj .ply formats.
I need some ideas and infos about it. I don't know how to analyse the things I have and how to calculate what I want.
Here I found an example of what I am trying to do but It doesn't need to be perfectly stable like that, Its for a school homework. Maybe you can give me some ideas about how to achieve my goal. Thank you for your help.
https://www.youtube.com/watch?time_continue=48&v=jOvaZGloNRo
I get 3d scanned object with kinect v2 and use PCL to convert it into point cloud.
I don't know about using PCL with Python or C#. In general you are looking at the following steps:
Filtering the points to the interested region
Segmenting the shape
Extracting the parameters
If you're interested in only Python, then OpenCV might be the best option. You can also develop the core logic in C++ and wrap it for Python or C#. C++ also has some nice UI libaries (Qt, nanogui), please see the following details for achieving the objective with PCL
Filtering
CropBox or PassThrough can be used for this. It'll result in similar results as shown in the image assuming that the frame has been chosen properly. If not, the points cloud can be easily transformed
Segmenting the shape
Assuming you want an average circumference, you might need to experiment with Circle 2D, Circle 3D and Cylinder models. More details regarding usage and API are here. The method chosen can be simple SAC (Sample Consensus) like RANSAC (Random SAC) or advanced method like LMEDS (Least Median of Squares) or MLESAC (Max Likelihood Estimation SAC)
Extracting the parameters
All models have a radius field which can be used to find the circumference using standard formula (2*pi*r)
Disclaimer: Please take note that the shape is circular, not ellipse and the cylinder are right angled cylinders. So if the object measured (arm, or bicep) is not circular, the computed value might not be close to ground truth in extreme cases

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