AW: Creating a planetarium using Ruby

[Unger R. <ric...@te...>]

Hi!

Wow! Now that sounds like a really cool project!

I don't think Ruby will necessarily help you here... Ruby is needed when =
you want to enable parallel, independant use of screens, specifically =
for multiple independent consoles.

What you want is more of a giant "Xinerama" setup. However, IMHO =
Xinerama may also not be the way to go - it might be quite some work to =
recode that layer.

Also, 20-30 Video-cards is a lot (last time I checked, I could put at =
most 6 in my Workstation ;) )... May I ask if you have already solved =
the problem of the hardware you will use?

If not, I think this will be the major area of work. I am not aware of =
any PC Hardware capable of driving 20 Graphics cards. If if you were =
able to hook up a PCI bus with 20 cards you would never be able to drive =
them in sync - the bus won't support that kind of volume of data. With =
PCIe you're getting closer. For example, Matrox is making 1-Lane PCIe =
GFX Cards, and modern PC Hardware often has 20 or more PCIe lanes. =
Whether the processor and bridge chips will manage to drive 20 cards =
sounds doubtful.

More likely you will have to use several PCs in parallel, with each PC =
containing several graphics cards. In this case you will need a software =
layer to distribute the graphics processing over multiple nodes in a =
network. There are existing software packages to do this. If you use =
OpenGL, the Chromium project is one such software layer for OpenGL. (I =
saw an article recently where someone ran Quake3 on 24 screens at a =
resolution of 10240x3072px using Chromium).
Using OpenGL may be a good choice in any case, as I think you could more =
easily implement the distortion needed for your non-flat projection in =
the OpenGL system than a 2D system like X-Windows.

May I ask what kind of total resolution you are aiming for? What is the =
projection area?

Have you solved the problem of the projectors? Were you planing to use =
rear projection or front projection? The way I see it, with front =
projection you would have a problem, since the projectors typically =
bleed quite a bit of light around the outside of their images, the =
joining lines between projectors would be very visible?

It's definately a very cool idea, the open source planetarium. Is there =
a website?

Richard Unger






=20

> -----Urspr=FCngliche Nachricht-----
> Von: lin...@li...=20
> [mailto:lin...@li...] Im=20
> Auftrag von De Gyves
> Gesendet: Samstag, 11. M=E4rz 2006 02:02
> An: lin...@li...
> Betreff: Creating a planetarium using Ruby
>=20
> There is a possibility to create an open project to build a=20
> planetaruim star projector. I have already made some=20
> configurations using Ruby+Debian to enable about 4 screens.=20
> Maybe it is not necessary to use Ruby (because of Xinerama)=20
> to accomplish the project, but, the question is: how many=20
> screens can manage Ruby? I think that ~20-30 video cards=20
> would do the work using projectors instead of monitors for a=20
> planetarium. Can Ruby work with this number of cards? Or,=20
> must I to do it with Xinerama? Has anyone made something like this?
>=20
> Of course, because of the ceil of a planetarium is not plane=20
> but concave, I'll have to recode some stuff in the drivers or=20
> somewhere else.
>=20
> --
> V=EDctor-Polo de Gyv=E9s Montero.
> (52) 55 2771 2423 (Cellphone in Mexico City)=20
> war...@ho... (just msn, don't send mail)
> (52) 971 71 20990 (Phone in Juchit=E1n, Oaxaca)
> Address: Independencia street & Morelos avenue, Segunda Secci=F3n,
> ZIP: 70000, Juchit=E1n, Oaxaca, M=E9xico.
>=20
>=20
> -------------------------------------------------------
> This SF.Net email is sponsored by xPML, a groundbreaking=20
> scripting language that extends applications into web and=20
> mobile media. Attend the live webcast and join the prime=20
> developer group breaking into this new coding territory!
> http://sel.as-us.falkag.net/sel?cmd=3Dk&kid=110944&bid$1720&dat=121642
> _______________________________________________
> Linuxconsole-dev mailing list
> Lin...@li...
> https://lists.sourceforge.net/lists/listinfo/linuxconsole-dev
>=20