Reverse-Engineering GTA V

An anonymous reader writes: Software engineer Adrian Courrèges posted on his blog a breakdown of the rendering of a frame in Grand Theft Auto: V. Each rendering pass is explained in detail, with all the techniques and the tricks Rockstar used to make the game run on 8-year-old consoles. It's a fascinating trip through the making of a frame and reminds us of how far GPU computing power has come. Here's a brief snippet from the beginning: "As a first step, the game renders a cubemap of the environment. This cubemap is generated in realtime at each frame, its purpose is to help render realistic reflections later. This part is forward-rendered. How is such cubemap rendered? For those not familiar with the technique, this is just like you would do in the real world when taking a panoramic picture: put the camera on a tripod, imagine you’re standing right in the middle of a big cube and shoot at the 6 faces of the cube, one by one, rotating by 90 degrees each time. This is exactly how the game does: each face is rendered into a 128x128 HDR texture."

Re:

[Falos]

[pigeon-mode intensifies]

This is how cubemap reflections are made in every

[Anonymous Coward]

Every game and piece of software, and have been made this way for decades.

Re:

[Ormy]

As someone who 100%'ed JC2 (well, 99.95%, which was the best you could do because of a bug) I beg to differ. The sky and terrain on JC2 looked amazing and indeed rival modern games including GTA5, but the extra detail and variety and sheer amount of stuff going on in each and every scene in GTA 5 make it a massively prettier game, even if each individual element is not much more detailed then any other recent large open world game. The reflections and water in GTA5 are way ahead of JC2. Never mind that G

Re:

[Purity Of Essence]

If you manage get past the summary and read the detailed three-part article you might actually learn something. Insightful, my ass.

How is such cubemap rendered?

[wonkey_monkey]

How is such cubemap rendered?

And how is babby formed?

Re:Is this all just speculation?

[UnknownSoldier]

Easy. By

a) examining the assembly from the pixel shader.
b) discarding all rendering until the end of frame.

The only "interpretation" is how the HDR tone mapping is applied but it is close enough to the real game that it is a minor point.

Re:

[war4peace]

That's where he lives.

Re:

[war4peace]

You get to pick. I vote for the latter :)

Re:

[MobileTatsu-NJG]

By the way, I fucked your mom in the poop-chute.

To bring this back on topic you'll need either ZBrush or ... heh ... Mudbox.

Re:

[Anonymous Coward]

How do you disassemble the pipeline logic on the GPU? You know, the thing that does most of the work. This isn't just occlusion techniques and tracing.

Re:

[Shinobi]

You use some of the dev tools available for that

Where can I find more?

[Ormy]

I am not a programmer, I do not work in the IT business, but I find this kind of stuff incredibly fascinating, its a major reason I still come here. So much so that I remember very clearly a particular article from a few months ago about auto-generating dungeons. Where can I find more?

Re:

[Purity Of Essence]

A good place to start might be the talks archived at the GDC Vault.
http://gdcvault.com/ [gdcvault.com]

You can read all back-issues of Game Developer Magazine there as well.
http://www.gdcvault.com/gdmag [gdcvault.com]

And sister website Gamasutra has loads of stuff like this.
http://gamasutra.com/ [gamasutra.com]

More low-level and rudimentary topics are covered by a couple of good YouTube channels.
https://www.youtube.com/user/B... [youtube.com]
https://www.youtube.com/user/c... [youtube.com]

If you want to dip your toes into game development without needing to know anything, check out

Re:

[Purity Of Essence]

Also, forgot to mention this, if you want to get in deep, check out Casey Muratori's Handmade Hero series of live-coding streams. See how a game can be built entirely from scratch without starting with prebuilt engines, special tools or middle ware. Follow along and make the game yourself. Every aspect is covered in incredible detail.

https://handmadehero.org/ [handmadehero.org]