Facility - Good and Bad Trev

This is a technical explanation for how Trevelyan first starts moving at the end of Facility in Goldeneye 007.

Mechanics

Research performed by Wyst3r:

When the cinemas begin to play, Trev will be between the tanks closest to the exit. Immediately, he begins to walk towards the preset 007C (see picture below). Once there, he will try to choose a new position to walk toward. However, he will be unable to, since he's currently unloaded. To see why this matters, you must understand how Trev choses his next target position.

There are 4 actions that control this, and all of them are essentially the same, with one small exception. All actions begin by finding the preset that is closest to Trev. In this case, it'll always be 007C, since Trev hasn't been able move away from there yet. After this, the game checks to see which presets are connected to the found one in the navigation graph. In 007C's case, it'll be 007E, 007D, 0076 (Note the order, it's the same that the game uses internally and it'll become important later). A complete list of possible targets then becomes:

1. 1: 007C
2. 2: 007E
3. 3: 007D
4. 4: 0076

The game will now begin to check if any of these presets lie within a 180 degree field of view, originating from Trev's position, and oriented along Trev's facing direction. Remember how i mentioned 4 different actions? Well the difference between them is simply which direction the FOV is pointing, either left, right, forward or backward (relative to Trev's facing direction):

I have numbered these directions according to their priority. The game will first check in front of Trev to see if any of the listed presets are visible within this field of view. If not, it continues by checking his right side, then left side (if neither front nor right found anything), and finally behind Trev. If there's more than 1, it'll chose the one that appears first in the list. For example, if 007C, 007E and 007D happend to be visible at the same time, 007C would be chosen.

Once a target has been found, Trev starts walking towards it. When he gets close enough, he will stop moving and again start the process of determining a new target. This explains why you often see Trev taking very small steps forward a couple of times before actually moving to a new location. He likely stopped slightly before reaching his position, meaning it'll still be in front of him. This way, the same target can be chosen many times in a row, until the small steps finally bring Trev past the preset so it's no longer in front of him.

Putting all this together, we can now begin to understand how good/bad Trev's actually work. Before you open the door to the bottling room, Trev will be unloaded. This means 2 things:

1. When Trev is sent to preset 007C in the beginning, he will end up [i]exactly[/i] at this location. 2. His facing angle will be 0 degrees, which in the picture above means SOUTH.

Just because Trev is unloaded doesn't mean he can't move. The problem is simply that in the above case, Trev is exactly at the position of preset 007C, which means it'll lie within his field of view, no matter which direction he looks in. So he'll choose 007C as his next target and move towards it, only to end up at the exact same location again (because he's still unloaded). So for the bigger duration of the level, Trev is "stuck" at 007C.

So how come it's possible to have Trev walk towards 0076 the moment you open the door? Well, when Trev is unloaded and moves from 007C -> 007C, he actually does move for 1 frame before he is "teleported" into the exact position of 007C again. And since his angle was exactly 0 degrees, this movement will be slightly towards south. Now, if you open the door at this exact frame, or slightly afterwards, Trev will now be ever so slightly in front of 007C, and will no longer find it during the first FOV test. Instead, he will find 0076 (all other presets are behind him). Thus, we get the "Good Trev".

I think it's impossible to know exactly when these small movements occur, but it's at fairly constant intervals, every ~0.55-0.60 seconds. The window after that is fairly small, only a couple of frames. For this to work, you want to have Trev inside your field of view at the moment you press B, so don't look down fully or anything wierd like that.

If you mis-time the door opening, Trev will load while trying to walk from 007C->007C, meaning he will do a kind of half-circle movement. This is the reason we often see him facing towards the bottles, he started at 0 degrees looking towards the south, then turned clockwise in a circular motion and ended up facing the bottles. (He could sometimes also end up facing north)

Opening the door is actually not the only way to load Trev. You can also look through the glass in the lab next door. You don't actually have to enter the lab, just move close enough to it so the window to the bottling room becomes loaded. I wouldn't recommend this though, as it seems very unlikely that Trev will move to 0076 this way.

Another way to influence Trev is with a quickpause. Same idea as with Aztec really, where quickpauses affects the guards' motions, helping glass odds. On Facility, if you do one or two quickpauses while opening the door, you'll see that Trev will move away from 007C almost 100% of the time. This could potentially help you get Good Trev's, but it would also mean you'd lose all your speed, which makes it a pretty bad idea. Strategy wise, i think it's best to stick to current WR strats.