2 April 2014

From point cloud to mesh


Now that we have point clouds what can we do with them?
Well my first idea was to use them as a reference to create meshes in a 3D editor.
But if you want to make a mesh from the point cloud itself, how can we do it?

This is a basic tutorial to create meshes from point clouds in Cloud Compare.
For that we need to install Cloud Compare.
Just go to:  http://www.danielgm.net/cc/  and download the program.
It's free but you can make a donation to the creator, he really deserves.

PVS creates point clouds and the ones from the sample project are stored in the folder ".../PVS/Sample Project/Reconstruction/Absolute". They are in the ASCII PLY format.
If you are interested in knowing more about the format, please visit  http://paulbourke.net/dataformats/ply/ .

Ok now let's start:

1 - Open Cloud Compare and drag the point clouds you want to treat inside.

2 - Cloud compare asks for each point cloud some questions, just click "Ok" for all. This may take a while.
If you are aware of a faster way, please share with me.

3 - You will see all the point clouds in the viewer.
Usually I change from orthographic projection to object centred projection. For that use the button on the left pane and change from

3 - The point clouds are separated, let's merge them.
Keep the "Alt" key pressed and with the mouse select all the points on the viewer or in the left list, select all the point clouds.

Now go to the menu and select "Edit->Merge".

4 - Now we have a merged point cloud.
We need to sub sample the point cloud to remove overlapping points and to get a workable mesh.
Once again, select the point cloud you want to sub sample.
Next go to the menu and select "Edit->Subsample".

  • On the method I use "Space".
  • I'm using 0,05 meters on the space between points.
  • Click "Ok" and wait.

We now have two point clouds. The original one (now hidden) and the sub sampled one.

5 - Now let's make the mesh.
You must have the sub sampled point cloud selected.
On the menu select "Edit->Mesh->Delaunay 2D (axis aligned plane)"

  • Select a value of 0.8 meters for the maximum edge length.
  • Pres "Ok" and wait.

The mesh is created. Uncheck "Normals" to see the coloured faces and check "Wireframe" to see the wire frame.

6 - Ok this is a bit chaotic, let's smooth the surfaces.
Select the mesh and on the menu go to "Edit->Mesh->Smooth (Laplacian)".

  • Keep default values.
  • Click "Ok"and wait.

Once again, uncheck "Normals" to see the coloured faces and check "Wireframe" to see the wire frame.

That's it, you now have a smoothed mesh reconstruction.
Play with the values.

21 March 2014


The first Project Video Scanner version is out!
It's an amateur and free program.
If you want to support further development and think I might deserve for the work made until now you can make a donation.
If you use the program for your work, I would like to know and a little reference to PVS would be welcome.

So what is Project Video Scanner (PVS)?

Here's a video to introduce you to PVS:

Short description:
The initial objective was to create point clouds of real roads from 3D video to use as reference to recreate the road in simulators. But you can use the point clouds anywhere.

Blablabla description:
I like car simulators and with so much people talking about laser scanning and similar solutions, I started searching for the cheapest solution to make laser scanning.
Why? Well if it's cheap maybe we could create a database on the web where people all around the world could deposit their scans and share data to the track creators.
Cheap laser scanning doesn't exist (at the moment I'm writing), so instead of laser scanning I decided that video scanning could be the solution.
I'm not totally convinced, but at least it was fun to create this program and sometimes I'm surprised with the results we can achieve.
Why video scanning? Well there are many videos on the web and I thought it could be possible to rebuild old tracks from old movies.
That's not so simple, but it's still on my mind and I might go for it, but right now what I have is reconstruction from 3D videos.
This is the first version and I have many ideas to enhance the system, not only on software side, but also hardware.
If you are searching for a solution to scan with high precision like less than 1 cm and scan cracks and things like that, just forget this and go laser. That's not possible right now and actual sims don't use those resolutions. If you want real, just drive a real car.

Here's a reconstruction made with PVS:

Ok, let's go and start installing the program. Go to the guide page.