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Re: Portal 2D (tech demo)

Posted: Fri Sep 09, 2011 3:02 pm
by The Doctor
You're seriously thinking with portals! :awesome: This has got potential!

Re: Portal 2D (tech demo)

Posted: Fri Sep 09, 2011 3:56 pm
by ljdp
The Doctor wrote:You're seriously thinking with portals! :awesome: This has got potential!
I'm surprised at how simple it was to implement, but I must thank vrld for implementing stencils, I wouldn't have a clue when it comes to talking directly to openGL so I can't imagine how valve did all this in 3d. It should also be possible now to do the portal-within-a-portal effect, brb going to find my thinking cap.

Edit: Ok I take back it being simple to implement, recursion is making me go crosseyed. :death:
I can get recursive portals to work if the angle of both are 0, as soon as they're any other angle they refuse to line up.

Re: Portal 2D (tech demo)

Posted: Sat Sep 10, 2011 12:35 am
by Lexsym
valve created a camera object, and projected it onto the "portal" and the camera's angles were set to that of the player's. In simplicity :P

Re: Portal 2D (tech demo)

Posted: Sat Sep 10, 2011 11:27 am
by GijsB
Lexsym wrote:valve created a camera object, and projected it onto the "portal" and the camera's angles were set to that of the player's. In simplicity :P
wouldn't it be better if they changed the 3D engine so, when a ray hitted a portal it will change position and direction?

Re: Portal 2D (tech demo)

Posted: Sat Sep 10, 2011 12:15 pm
by Taehl
No, because Portal (like all games) isn't rendered via raytracing...

Re: Portal 2D (tech demo)

Posted: Sat Sep 10, 2011 1:35 pm
by GijsB
hmm.

Re: Portal 2D (tech demo)

Posted: Sat Sep 10, 2011 2:38 pm
by ljdp
Taehl wrote:No, because Portal (like all games) isn't rendered via raytracing...
Surely raytracing must happen at some point low level, in the graphics card?

Re: Portal 2D (tech demo)

Posted: Sat Sep 10, 2011 2:43 pm
by bartbes
Nope. In fact, raytracing is never used in games, because it is too slow, it provides amazing detail, but can't be done realtime.

Re: Portal 2D (tech demo)

Posted: Sat Sep 10, 2011 3:43 pm
by GijsB
bartbes wrote:Nope. In fact, raytracing is never used in games, because it is too slow, it provides amazing detail, but can't be done realtime.
And there you're wrong, search it up ;)

Edit : As you can see here ; http://www.youtube.com/watch?v=blfxI1cVOzU (IN 2007!!)

Re: Portal 2D (tech demo)

Posted: Sat Sep 10, 2011 4:05 pm
by slime
GijsB wrote:
bartbes wrote:Nope. In fact, raytracing is never used in games, because it is too slow, it provides amazing detail, but can't be done realtime.
And there you're wrong, search it up ;)

Edit : As you can see here ; http://www.youtube.com/watch?v=blfxI1cVOzU (IN 2007!!)
That's a demonstration, not an actual game. It can be done realtime, but realistically right now you can't do raytracing plus everything else that a game needs to do at the same time (unless you want to make a game that only $2000+ computers can run).