HN user
Could you link to it please?
I've not tried it on anything else, but I remember thinking that it has a lot of potential uses. Also I only used it on gray-scale features, but I'm sure it could make use of full RGB too. I'll have to try it some time!
Hmm looks like they have, well here's another link to it: https://dl.dropboxusercontent.com/u/1672291/scrabble-referee...
This is great. I particularly like that they also automatically generated dirty versions for their training set, because that's exactly what I ended up doing for my dissertation project (a computer vision system [1] that automatically referees Scrabble boards). I also used dictionary analysis and the classifier's own confusion matrix to boost its accuracy.
If you're also interested in real time OCR like this, I did a write up [2] of the approach that worked well for my project. It only needed to recognize Scrabble fonts, but it could be extended to more fonts by using more training examples.
Nice work!
A little trick you can use here is squared distance which avoids the relatively expensive square root (also do the square in-place rather than pow) so your distance function becomes:
(d - a) * (d - a) + (e - b) * (e - b) + (f - c) * (f - c)
You will need to also square your threshold values.
Nice example, but ray casting like this is overkill for this effect and with a low number of rays it's pretty inaccurate.
I prefer using the technique shown in this classic article on 2D soft shadows: http://archive.gamedev.net/archive/reference/programming/fea...
The basic idea is to project the geometry, rather than ray cast. I've implemented this sort of technique in the past and it works well.