The GTA 3 developer explained why players had to be slowed down due to poor optimization
Obbe Vermeil, a programmer who worked on several Grand Theft Auto games, said he and his colleague Adam Fowler had to come up with workarounds to get GTA 3 to work on the PlayStation 2.
Vermeil said:
There was no way for us to fit the entire GTA 3 map into the PS2’s memory. Streaming involves loading models from DVDs as the player moves. This was the most difficult technical challenge in the development of GTA 3, which Adam Fowler solved.
The problem was that players would see poorly detailed buildings and missing roads as the game couldn’t load them in time when moving. Vermeil explained that models load faster the closer they are to the DVD because the DVD needs to speed up and slow down as the head moves to a different track. Fowler tried placing models closer on the DVD and repeating frequently used files, but this was still not enough, so the programmers had to slow the player down.
In Portland there was an islandwide slowdown. This was the worst case scenario. The player could move quickly and there were many buildings to load up on. Because of this, the artists changed the road layout to slow down the player.
In other problem areas, we increased the air resistance on vehicles by about 5%. It was almost imperceptible, but it helped.
It’s because of these streaming issues that flying in GTA 3 was limited.
As models were loaded into memory and then removed, the memory became fragmented into smaller blocks. So Fowler’s code kept moving the models around to fix the flaw.
This was difficult as sometimes the models needed to be moved before they could be rendered.
Vice City, the next game in the series, did not have the same problem, as the code was improved, providing better compression of models and textures, and loading detailed versions of buildings only when the player was not flying.
San Andreas has received even more optimization. The abundance of poorly detailed countryside between parts of the city greatly helped streaming. However, it had its own characteristics – for example, crashing planes .