Voxel Editor Version 0.2

I've been working away at improving the Voxel Editor program and have gotten the next prototype into a tidy enough format to post. It has a proper interface now as well as a much nicer program structure!

Only a short explanation today, as before find the embedded program at the bottom of the post :)

Generic Status Update

This week was busy with things not related to programming projects. So just a little update here to keep to my word of posting weekly. 

My idea of creating an image of a Voxel schematic with the information to create it encoded in the image data still needs more work. I think using the alpha transparency channel is messing up the values in the three colour channels per pixel. If I don't make any progress on fixing this soon I'll put the idea on the backburner and refocus on better interface elements. I still feel this is the main programming project I'll work on for a while.

Speaking of other projects, been messing around with an interface for a text adventure. Played in the browser naturally as downloading programs is sooo 2010's :P I have a vague sense that a command line based system of input and output is the simplest and least resource intensive kind of interface a program could have. More complex would be a minimal graphical system, say flat colour squares. Then some kind of 2D render with sprites and finally a full blown 3D render. 

I'd like to investigate having a program that allows the simulation/model/state etc. to be visualized in any of the four manners. It would be good to have modular versions of each display method available to plug into any project I decide to tinker with :)

Voxel Editor - Savefile format

Progress is going well on the Voxel Editor I posted a prototype of last week. I have mainly been restructuring the code; as it started off as a little experiment I didn't bother to adhere to an overall structural plan initially, just one huge source file (so many globals D: ). New code base is ordered much nicer with the usual model, control, view split. I will be writing a better user interface for the colour picker as I disliked how each browser I tried the prototype on would create a differently sized range slider.

Feedback from the post on the subreddit VoxelGameDev was good, I'll definitely share this project there again once I get all the interface elements sorted. Inspired by some of the discussion there I've been working on improving the JSON savefile format.

Improving JSON savefile format

Invoking JSON.stringify() on the JavaScript object holding the voxel schematic block data results in a very wasteful representation; the 3D nature of the data is represented by nested arrays:

schematic.block = [ [0,1,0], [0,0,0], [1,0,1]

                    [1,1,1], [0,1,0], [1,1,1]

                    [0,1,0], [0,0,0], [1,0,1] ];

When a much more space efficient representation would be to omit the square brackets and note the dimensions elsewhere. Concatenating the block data into a string results in less than half the characters before:

schematic.block = "010000101111010111010000101"

Even better results can be obtained if the block data is compressed. Wanting the JSON savefiles to be human readable I decided run-length encoding would be easy to implement for me or anyone else who wished to parse the savefile:

schematic.runLengthEncodedBlock = "AB4ABA4BABA3BAB4BABA"

With a run of multiples of the same symbol being denoted by a number followed by the symbol. 

(A = block 0, B = block 1). The size of the run-length encoded data depends on how varied a voxel schematic is but on average it is a quarter of the concatenated version. A quick check with zip file compression shows that it is *only* half the size of the run-length encoded version, not bad for a compression algorithm that is so easy to implement :D

A picture is worth a thousand words

Having a readable savefile format is great for metadata such as creator, creation date, colour palette and dimensions. It doesn't allow the user to quickly see what the schematic is off though. I have added the option to save the isometric render of the schematic. Which serves not only as a quick preview and easily shared image but also has the data to reconstruct the voxel schematic embedded in it! I believe the game Spore allowed people to share their creatures with such 'encoded' images, shame the game wasn't too compelling. Here's a preview of such an encoded image, can you tell where the schematic data is stored?

Voxel Editor

This week I completed a very neat tool; a browser based voxel editor. This is the first proper programming project post of this year, happily it's a really neat one :)

Click through for an explanation of what the tool does, some example voxel models made with it and finally the running program itself.