It doesn't. In most cases, recursive rendering through portals is limited to 2 instances by default. This can be (pointlessly) increased if the user wishes though, resulting in a pretty significant performance hit.

wtf where are your AA I se corners everywhere

It doesn't render infinite depth.

I believe the answer is cocks.

>>2627797
i can see that theres only 2 portals when i look in the blue portal but when i look in the orange portal there seems to be more than 2 portals..

>>2627797
and after that, it just essentially copypastes for a bit if i remember correctly.

It will render a max of 9 I think, after that it just shows a blurry screenshot of the 9th portal.

It sure is /v/ in here.

>>2627913
talking about performance in a program.

>>2627903
This. I vaguely recall a developer's commentary that says so.

Raytracing would be > * for Portal 2.

>>2627990
It would be fuck all for system requirements. The main draw of Source games is that pretty much any computer worth more than $100 can run them just fine.

>>2628003
do you manually post all those pics or do you have something set up to randomly post Kaworu/Shinji?

Badly and slowly, to be honest. That shit runs fast just because the graphics are so bland (as in very little geometry).

As people have already said, watch the commentary. It just renders the scene again, using the stencil buffer to clip it (it clears the stencil buffer and draws the portal oval in it, then draws the scene with stencil testing enabled). It does this recursively (the oval is drawn summing 1 to the stencil buffer on each iteration, then draws only where stencil matches the pass number, so if two ovals intersect it draws only over their intersection).

For a proper implementation of portals (and I'm not talking just about graphics performance, but also featureset, versatility, and physics interaction), look at Prey. Shame that as usual the better game gets the worse tech and vice-versa.

Also on OP's pic you can clearly see that only the first two iterations are real, the rest are faked by drawing the image over and over.

>>2628021
I do it manually. Once I find one I like particularly well (which sometimes takes a while because I have an extensive collection to weed through), I select it and continue on my merry way. I once considered having an automated process for doing this, but I don't like just posting a random pic, I only like posting the pics I really like.

>>2628030
That's not to say that they didn't pull off something very believable, though. I really liked the execution. The physics bubble approach makes sense for the Source engine, the drawing method is great considering the amount of time they worked on it, and overall, the gameplay isn't hurt at all by not using "true" portals.

Prey was an astounding game considering the level of worldly interactions. Not just the portals, but the gravity for the small planetoid objects and all the other nonsense that happened. I really enjoyed it.

>>2628066

Well, it was adequate, albeit barely.

When I played with it a little bit I started noticing problems where if you pick up an object and move it through a portal while holding it and keeping an eye at the other end, it looked really bad; and also you could "feel" the fragility of the physics bubble approach. In Prey, portals were truly seamless (and free-shaped). In fact, at some places there weren't visual hints of their existence and it was impossible to tell they were there.

Moreover since placing portals requires significant preprocessing you can't realistically move them or anything of that sort. I think that did hurt the game, if by omission.

once you understand what was done in 1997 you will understand what was done in 2007

>>2627792
Play the game with developer's commentary

>>2628131

I'm sorry to break it for you but mirrors != portals.

Also, there were "portals" back in the first Unreal, and probably in earlier games that I don't know about. They looked as good as modern ones but didn't handle physics seamlessly (they just grossly teleported stuff).

Physics iteration is where the real challenge is at. Rendering is pretty easy.

>>2628168

> I'm sorry to break it for you but mirrors != portals.

(Although rendering might implement them as such, the "physics iteration" point still stands. In any case the Build engine was a raytracer, not a rasterizer, so it's kind of different)