well the magic box is still a do-it-yourself idea, but i’ve found articles of a university in germany trying the same stuff and do know from my mate that it would use well known techniques, simply not used for this kind of thing yet. and over all, it’s really cheap.
i do know the matrox solution now as i had the chance to test it, and it’s cool, for a small amount of screens. but what i’m tryin to realise here is a way cheaper solution for way bigger projection environments. think about certain festivals out there, e.g. the urban art forms in austria, where approx. 16 or more screens are seamlessly surrounding the main stage/crowd. if you want to project one large connected picture on this high amount of screens using the tripleheads doesn’t seem to be very professional to me, nor is it really easier to overview or achieve.
having 16 screens you would need 6 times matrox triplehead @ 200 eur, with 6 outputs from your pc (with at least 3 gpu) [=all in all about 2000 eur with good gpus](=all in all about 2000 eur with good gpus).
using the hz box to switch output slot at every new frame you could achieve the same thing with only 1 of these boxes @ approx. 150 eur, with 4 outputs @240 hz from your pc (with 2 gpu) [all in all about 700 eur](all in all about 700 eur).
so for me the biggest advantage is money, and i believe if working this could be a more professional solution for large environments, as all your n outputs come fom one box, and not n/3 matroxs; over all it’s in output not restricted to vga, as we’re buidling one with vga in and bnc out!!..). you can also see that if going even higher in screen count the difference of pricing gets even bigger, as you could easily built this box with a large number of in and outputs without making it a lot more expensive; but you get an extra 200 eur for every 3 outs with triplehead AND the number of gpus needed also increases faster using tripleheads.
my mate building the box for me also believes that 240 hz is not the maximum possible or that this value could be hacked somehow, but i haven’t checked this yet. dreaming of 360 hz out it would be possible to achieve the same result with one ouput as with 2 matrox and two outputs. 3 outputs would then result in 18 screens, which is simply not practicable to do with matroxs…in my opinion.
despite of all of this my very old geforce pcx 5300 is capable of 120 hz output, so 2 outputs possible per vga out, but it is not capable of the minimum supported resolution for a matrox triple head. i’m not using this gpu for this project, but it’s good to know that if the box is built i could even manage 4 screens with an old hardware like this. or use it in combination with newer hardware, e.g. having a good card with 240 hz serving the first outputs and the older one for the last 4- all done with the same box having 2 inputs!!!
nevertheless, i’m not asking you to believe in this idea, as it’s still not sure if it’s all going to work out- but i would be really thankful if you guys could tell me if i’m doing the vvvv part right, using the perspectivelookatrect node? as said for me it seems to be it, but i haven’t been using the projection/view transform possibilities yet, so there might be something i’ve overlooked…
i’ve set near plane to 0.0001 and the same value for z at the distortion pin, i don’t understand these values yet but it looks like that’s cool.