how Gears of War 1’s train level works

I just completed Gears of War 1 Reloaded, a remaster of a remaster (lol same), and it ends with a train level. It’s the usual thing, a mostly-static level pretending to be a moving train by deploying various illusions, but since it’s possible that Sleight of Hand will ship with one of these, I was curious as to details of the exact approach taken in Gears. Then I remembered the original Gears 1 shipped with the editor, so I could just open it and find out! So I did. No surprises, but it’s always fun to look at stuff like this anyway. Here’s a video about it.

The video is the meat, but I’ll sum up textually anyway. As you might expect (or perhaps you wouldn’t, so convincing is the illusion), the train tracks themselves are just a plane with a rapidly panning material (technically two, there’s a road next to the tracks). The train itself is just static, a normal level, except for some of the rear cars which get blown off the train at one point, and these are keyed using Matinee, the Unreal Engine 3 equivalent of what’s called Sequencer today. Fun fact: until late in UE4 (maybe even now?) if you opened a map that contained a Matinee (which you could, since it still existed until mid-UE4) the Matinee is automatically converted to a Sequencer, with, in my experience, pretty much zero loss of anything. Great stuff.

Matinee also controls the scrolling terrain in the background. This is dead simple: there’s a mesh of a square chunk of ground, it tiles seamlessly, and it’s keyed to move its length in the direction the train’s not moving. The mesh is duplicated a few times in each direction, and those duplicates are all attached to the first one. The play rate on this is modified to give the impression of the train speeding up or slowing down – it speeds up when the back carriages come off.

This whole arrangement is done a few times – looping terrain, looping city, looping tunnel in the tunnel part. Occasionally there’s a bridge, or some old cars on the side of the road, or telegraph poles, or whatever, and these are all just stuff Matinee’d to move past you real fast every so often. The inky stuff and weird aliens in the sky are just Cascade emitters (that’s pre-Niagara particles, for the younguns), which I suppose probably means they don’t move at the right speed when the “speed” of the train changes, unless they’re handling that somewhere – didn’t check. Doesn’t matter anyway!

I wish more games still had their editors packed in. A lot of Unreal 1-3 games did – you can do this with Mirror’s Edge and Deus Ex! But I think because of various bullshit, this is prohibitively difficult to do on UE4 and 5, or it has been, anyway. I really want this fixed, ideally retroactively.

It’s not why I’m here, but having just completed the remaster, I realise looking at the original that they fucked up the boss fight. Early in the game you’re trained that Nemacyst, weird bat things, will eat you if you’re not standing in light if they’re around. This boss weaponises them against you so that you have to consider both regular cover and light at the same time – looking at the pic below, you get it; only stand on the lit tiles while the bats are out. In the remaster, the whole level is brighter and you can barely tell where to stand. Oh well.