ply2csv takes PLY files and puts out Data.csv.
SculptrVR is a nice VR app available for several platforms.
It enables you to sculpt things out of nothing using additive and substractive operations in a virtual environment.
Unlike the most programs that let you create things in VR it uses voxels (octree based) under the hood and only uses triangles for visualization.
That said it seems like the perfect solution to me to work on the results of 3D scanning, which create clouds of unconnected colored 3D points.
Creating meshes out of nothing to use these point clouds can be a pain.
Using SculptrVR we might be able to work on these point clouds and use SculptrVR to export meshed models to other applications.
You are going to need some PLY file. There are some expectations to meet that I assumed to be acceptable during writing.
- binary, little endian encoding
- no normals on vertices (since they are muxed into the vertex stream it breaks my code)
- nothing but coordinates and color to be precise
- your model should be normalized to a [-1, 1] bounding box (for scaling)
All these requirements should be easy to meet, exporting you model as .ply with MeshLab and disabling everything but vertex color in the export.
Make sure to check binary export. (No ASCII support)
I have prepared binaries for Linux and Windows. You may grab a suitable version from the bin/ folder of this repo.
You are expected to run this from any kind shell. (sorry no GUI(, yet?))
Since I even use bash (MSYS2) when on windows I have no idea how this would look on the default Windows command line.
But you should be able to figure it out.
Be warned: The complete syntax was just changed to use flags!
If you have used another version before, you still should read this carefully again.
$> ply2csv
-h this text
-help
this text
-massive
try to create more dense data by using multiple voxels per point
-o string
use this filepath as output (default "Data.csv")
-scale float
multiply you models coordinates by this factor (default 100)
-sphere float
enable sphere mode and put spheres of this size (default -1)
- All three modes accept an extra
-o <output-file>flag. - The Y & Z axis will always be swapped While saving, because ply default is Y-up and Z-depth.
./ply2csv <your-input.ply>
ply2csv will take your points, scale their coordinates by the default scale factor of 100 and raster the resulting coordinates to int.
If several points fall together due to the effect of rouding (which is actually a good thing to create more dense data), the colors of all those points will be averaged.
This effect should be used to scale your point cloud to an optimal size, where most voxels are touching each other, but you don't loose to many of them because they got merged.
To use a scale factor other than 100, you need to use the -scale flag
./ply2csv -scale 768 <your-input.ply>
Go play with scale!
This mode was implemented to satisfy another CSV format requirement one could use to import data into SculptrVR.
It's a good idea to think of this mode as being unusable in SculptrVR at the moment.
To use sphere mode you need to use the -sphere flag - most likely in some combination with -scale, eg.:
./ply2csv -sphere 1.5 -scale 256 <your-input.ply>
In this mode ply2csv will only scale coordinates, but not raster anything and neither colors nor vertices will be merged. As a result the ouput will be populated with (scaled) floating point coordinates and every point will be interpreted as sphere later on. The size of that sphere will be the value that you specified, so it is fixed for all points.
Think of cm as base unit for a size estimate.
To get a good model with mostly solid geometry you need to play with scale and sphere-size. Again optimal values depend on your data.
Be warned: This mode will use a lot of RAM during the import.
Massive mode is a slightly modified version of the default mode, which does not only place a single voxel per rastered coordinate, it places seven of them in the form of a 3D cross.
Use massive mode like the default mode with an extra -massive flag.
./ply2csv -massive -scale 768 <your-input.ply>
The -massive and -sphere can not be combined (that would make no sense).
This mode actually implements what sphere mode is meant do at SculptrVRs side, but it does so while exporting data.
It helps to create massive geometry that could not only be used if the containing SculptrVR layer is set to voxel, it creates geometry that should be two to three voxels thick (depending on your data) while still maintaining color accuracy of one voxel in most cases.
Geometry like this can be smoothed without being destroyed or removed in the process. Also you might export it as a real mesh without that voxel look later on.
It's a little secret, actually - and it does only work for the PC version!
You have to move the Data.csv file into a folder named CSVs at the top-level of the SculptrVR installation folder.
Which is not your documents folder.
Here's a piece of my SteamLibrary to help you figure out where:
SteamLibrary
└── steamapps
├── common
│ └── sculptrvr
│ ├── Engine
│ ├── SculptrVR
│ │ ├── Binaries
│ │ ├── Content
│ │ ├── CSVs
│ │ │ └── Data.csv
│ │ └── Plugins
│ └── SculptrVR.exe
If you created that folder and put Data.csv there, you may press ctrl-shift-L anytime in SculptrVR to load the data.
Be sure that the window has focus (if you see a steam dialog in front, click into SculptrVRs window).
If you exported plain single voxels you need to set your current SculptrVR layer to block mode!
Otherwise it's very likely that most of you geometry will be invisible.
The other two display modes try to smooth surfaces, which will totally eat up a single layer of voxels - especially when there are holes in it.
If you used the sphere mode…
then you should see spheres popping up, but the whole import might take up a minute until all spheres have been placed.
Actually I couldn't test this successfully for at least one time, the placing of spheres seems to depend on your viewing scale so scaling in and out messed up my first import.
The next try I had been waiting patiently until all my RAM got eaten up. I don't have test data with less than 800k points, which seems so be too much for sphere placement.
The RAM usage is directly connected to the level of detail you configured your sculpting tools to.
Nevertheless I got the format right. So if this is useful to you, have fun!
Most of the time, when you're tempted to use sphere mode, just use the new massive mode instead.