Binvox 2 LDR (Part 3)

So here's my binvox to ldr converter with brick optimistation and layer rotation (to add strength to the resulting model).  You need python 2.7 and numpy installed - unzip the archive and it should run from the resulting folder - there is a binvox file (moo.binvox) for testing which the code will use by default and the binvox rw file (which my code calls to read the binvox binary).

https://drive.google.com/file/d/1ypVxLItw2attg6j1iMsJdyPzdEVRDDYk/view?usp=sharing

You can use it using the following line in the cmd window

"C:\path\binvox2ldr.py" "C:\path\myfile.binvox"

Here's what you should end up with if you run the code without your own binvox file - the code also adds a STEP for each layer of the model.

Currently all the output is grey - coloured bricks will require an alternative solution as binvox does not support colour (that I can access anyway) - I'm looking a Goxel, which I think should work (http://guillaumechereau.github.io/goxel/) but it will probably be the New Year before I get back to this now.

If you are making your own binvox files (from .obj's) I sugest using the:  -d 32 -rotx parameters during the conversions as this makes a relatively small model and rotates the obj so the bricks are pointing upwards (well it works for me anyway!)

Here are some more of my model conversions....

Binvox 2 LDR (Part 2)

Using the binvox python parser allows relatively easy access to each voxel layer slice in the binvox file - once a voxel slice is transferred to a numpy matrix it's then possible to translate each voxel into a single 1x1 Lego brick...

I've included the code to do this here but as I've noted previously a 1x1 brick model isn't much good if you want to actually build a physical representation of the 3D object in question - you need to optimise the voxel matrix for each slice of the model into larger bricks;  and there is a Perl script to do just that here.  This Perl script optimises the voxel slice grouping individual voxels into larger Lego bricks - Exactly what I needed to do in a python script!

One of the disadvantages of this Perl script is that it does not add a strengthening element for each layer in the voxel matrix (so each layer is simply build on the layer below often using similar bricks) which is something that had been raised at London AFOLs, consequently I thought it would be good to try to add some strength to model by rotating each layer at 90 degree's to each other during the translation of voxels to bricks - this would automatically add a degree of strength to any subsequent build.  The other disadvantage with the Perl script is that you have to go through an intermediary text file before you can process the binvox file - it's not a major problem but it would be nice to try to get everything done in one go from binvox to LDR.

Binvox 2 LDR (Part 1)

Following a discussion at our last London AFOL meetup, I've taken a slight diversion to look at creating ldr files from binvox files - Binvox is a small program that voxelises 3D files (like .obj) into a voxel model.  Binvox is a good solution for transferring 3D models into games like Minecraft and I used it a while back to help create a simple animation system in Minecraft (a long time ago!)

Binvox to Minecraft translation is relatively straight-forwards as nearly all Minecraft's main components can be considered as a single voxel element.

Binvox to Lego presents an additional challenge as Lego doesn't really work if you translate each voxel to 1x1 brick as the resulting physical model (if you tried to build it) will simply fall apart.  There is already a mechanism to go from Binvox to Ldr here using a Perl script.  This script is a two stage process requiring you to convert the binvox file to a txt file so that Perl can parse the txt file but this Perl script adds an important element for Lego in that it optimises the voxel matrix for each layer into larger Lego bricks, so that you are not simply building with 1x1 bricks.

This Perl scripts works (and is probably one of the easiest Perl scripts to read that I've ever encountered!) but I wanted to see if I could bypass the requirement to translate the binvox file to txt and also add some strength to the model by rotating layers at right angles to each other.  I also wanted to code it in Python, as my Perl is rustier that a rusty nail that has been left in a jar of salt water for 10 years (which is also how long it's been since I've written any Perl!).

My starting point was this Binvox python parser which would take the hard work out of having to deconstruct structure of the binvox file.  With this is should be relatively easy to convert Binvox direct into LDR files...