VG Programming Question

There’s something I’ve been wondering for years now, just never enough to ask anybody about, but here goes. I’ve noticed for a long time that a curved 3d surface in a game, an arch over a doorway for example, will always be a collection of straight lines at different angles to each other, rather than a smooth curved line. A specific example I remember is an old WWF Smackdown game where The Undertaker’s bike wheels were friggin’ octagons that didn’t move (He slid down the ramp on these blocks). Since then I’ve noticed it more subtley but it’s still there, even in the most graphically impressive games. The vents in Bioshock that the Little Sisters came out have it if you get close enough. I saw it in Mass Effect, and a GTA 4 trailer I just watched. Mass Effect has perfect facial modeling yet they don’t draw 3D circles. Is it a cost thing or a disk space thing?

Does anyone with some programming knowledge or plainly just more knowledge than me know the specific reason for it? It’s becoming a pet peeve of mine.

Well, it’ll take up more polygons to create a very smooth looking surface on, say, an orb. Here’s an example I did below.

http://img2.*********************/uploads/th.2e261abc00.jpg (http://img2.*********************/image.php?2e261abc00.jpg)
(notice the slightly sharp edges. It has a low poly count)

http://img2.*********************/uploads/th.8474544960.jpg (http://img2.*********************/image.php?8474544960.jpg)
(high poly count. High detail)

In the industry they try and use more polygons where it’s needed or where people are most likely to look at longer (characters for example). Then again, the more powerful the hardware the more detail that can be put into an object or level. More detail, more polygons etc…

If everything was super detailed the hardware couldn’t handle it at the moment. It’d slow down.

Game developers need to cut corners when needed but it does take skill to make some appear more detailed than it really is.

Hope that helped!

Think about it – a computer monitor is made up of pixels – squares. A group of squares can only create rectangular objects. Additionally, all games are programmed using a variation of vector graphics – graphics constructed using lines. Even though special algorithms can be applied to them to create curves (called splines), it’s still made up of lines.

If you want to get even more technical, you’ll find that in real life, there is no such thing a true curve. If you look close enough at ANY curved surface – and sometimes you have to go down to the molecular level – you’ll find that at some point it is an optical illusion made by the arrangement of its parts.

Well, every 3D object is made out of polygons. The rounder a 3D object appears to be, the more polygons are needed. Al those polygons need to be rendered by your GPU/CPU. So, you can only use as much polygons for a 3D model as your targetgroup’s hardware can render in a certain amount of time. Thus, 3D modelers use more polygons for important 3D objects, and less polygons for objects in the background.

(edit: lol in after Denny)

Right, that all makes sense. Thanks a lot people. Hopefully it won’t distract me from the gameplay anymore. Thanks for those renderings Denny. The difference between the polygon counts makes it a lot easier to understand.