SiN and SiN: Wages of War/Game Mechanics and Glitches
From SDA Knowledge Base
If a trick applies to only some versions of the game, note which ones that is.
SiN runs on id tech 2, i.e. the Quake II engine. There are some differences but many tricks work just the same. Read below for a detailed explanation of how the physics work.
General Movement
- crouch jumping: In SiN, crouching in the air pulls your head down more so than your legs up. Because of this it isn't useful for reaching higher ledges but can be used to not get stuck jumping through gaps or into ducts.
- crouch falling: If you crouch before falling off, you avoid some fall damage. (works even when already jumped?)
Movement symmetry: In SiN the physics have no inherent differences based on which of the four cardinal or diagonal directions you're moving in relative to your facing. For this reason you can perform any basic technique in any of the eight directions, not just forwards or backwards. Sometimes you might actually want to do this too in order to, e.g., be able to aim in a given direction while moving or because it requires less mouse movement.
Movement speed: The base movement speed in SiN along both axes and diagonals, and also with movement up and down ladders is 320 in-game units (UPS). With most movement, the fastest way to accelerate from 0 to 320 is by just accelerating in a straight line. This should ALWAYS be done before starting to trill, wall strafe, or circle jump.
Trilling: This is a basic movement technique where instead of just holding down one movement key you move in a given direction and tap the perpendicular direction keys rapidly to increase the base speed by a noticable amount (up to about 370 UPS) although lesser than wall strafing and circle jumping. You're thus accelerating alternately at 45 degrees on both sides of the main direction of movement. The advantage is you can perform this technique in close quarters without relying on walls. You can do trilling on the ground or underwater. It doesn't increase your speed in the air.
Wall strafing: This is a basic movement technique where you hug a wall while running and accelerate at an angle that faces the wall itself at about 40 degrees to increase your speed to around 480 UPS. This means if you're using forwards and right to strafe against a wall on your right, you need to face an angle of about 5 degrees to the left of what would be parallel to the wall. Remember to first get to your base movement speed by accelerating parallel to the wall.
Notice this only works against vertical-ish walls. You cannot wall strafe in the air but you can underwater if you find suitable surfaces.
Circle jumping: This is a basic movement technique where you accelerate on the ground in a circle as if slinging yourself to temporarily exceed the base speed. The technique gives you around the same boost as wall strafing (480 UPS) but can be performed anywhere where there's a little bit of space for the circling and starts a series of hops in any direction including not parallel to walls.
The fastest way to perform a circle jump in SiN is probably to move forwards until hitting 320, then holding down +left or +right while rotating in the same direction through an arc of around 45 degrees (maybe even less). Practise this in open areas to get the feel for it.
Wall strafing might be better if you are okay to move parallel to the wall because of its lesser setup time. It's also more resilient against incoming fire and may make it easier to dodge enemies.
PRESERVING YOUR MOMENTUM: After gaining extra speed, you can keep the speed across gaps or without having to continue trilling/wall strafing/circling by FIRST releasing all movement keys (!) and THEN jumping a microsecond after. This is because air strafing will instantly reset your speed to 320. If you need to shoot at something on the side, or just rotate around, you can also do that during the jumping without losing time.
Because the game buffers one jump you can just hold the jump button down between hops. It's a good habit to get into to re-depress it soon after hopping so you will never fail hopping up stairs/ramps etc.
Air strafing: You can strafe in a circle in the air. This won't increase your speed (and will reset it to the current base speed in fact) but will at least enable you to get around corners while airborne. Extra useful when on adrenaline when normal air movement is made clumsier. You can also use this ability when on adrenaline to increase your travel distance by "wiggling" left and right after you jump so you don't overshoot it.
Adrenaline/mutagen: When on either adrenaline or the mutagen, your base movement speed along both axes is approximately doubled. The downside is you lose the ability to slow down during leaps (once attained a higher speed) and can only air strafe to control your movement. You can only ever hold one of each, and the mutagen injector is only found in one level, whereas adrenaline is found in multiple levels.
Water movement: It might be fastest to use both jump and trilling while facing the direction of movement if you're generally moving upwards, or crouch if moving downwards. Note that it's never fastest to use just jump or crouch by themselves. Wall strafing also works underwater though is less likely to see as much use.
Ramp jumping: This is a basic movement technique that arises from the way jumping is handled by the engine. Every time you jump off a surface, the jump adds to rather than replaces your current upwards velocity. Because of this, if you can jump twice or more times in rapid succession, you'll be able to get a much higher jump in total. In practise surfaces that are lower than the lowest crates are very difficult to ramp jump off, and objects that you can just barely reach are the same, because you've already lost all your momentum when you land on them.
You don't actually have to jump, you can just slam against the surface without doing anything and get carried along, but you don't actually seem to be boosted by doing it that way.
Bumping (IS THIS A THING IN SIN?): When you hit a slanted surface at a speed, some of your horizontal velocity is converted into vertical momentum, thus allowing you to reach somewhere slightly higher up. In practise you still always want to jump off the base of the slope whether or not you have extra speed.
Rotating at high speeds: if you've obtained a high amount of speed and want to keep it while adjusting your movement direction, look for walls that you could aim at to get bumped in the right direction by. Otherwise try NPCs, objects or anything. Enemies could shoot you to give you the boost you need. Weapon boosting off walls is another idea.
Crouching can give you extra traction in some situations (observed in some places with water running down a pipe)
Swimming upstream: You can usually just swim right up cascading water. It might help to save spam.
Jesus walking: Probably depending on your angle of incidence, you might be able to avoid sinking into water completely just skimming across the surface instead. Just hold down jump.
Wall rockets etc. - the idea is to use a rocket or something for a sidewards boost when e.g. falling. If you can, use air control instead.
Trees: Trees have strange hitboxes. Some of them extend most of the way up, some end only a little ways above where you can jump to without parkouring. Some of them don't even have hitboxes at all. You should look into possibilities of using trees and other unusual entities for parkour.
Getting out of water: Build up speed to make it possible to exit water in more places.
I've seen at least one spot where I couldn't get the character to jump out of the water until I crouched, presumably giving him the foothold he needed.
Getting on crate-height things: By crate-height we mean the height that most typical crates have that makes it difficult but not impossible to jump onto them. The more speed you have the easier it is to get on the object. That's why if you're running parallel to the thing, you can try to wallstrafe along it (at the usual 50 degrees off the parallel) and jump. Suddenly switching your angle to face the thing more directly might also help. If you approach it perpendicularly try trilling before jumping but with this approach you can't help having to just time it well. Otherwise doing a kind of "bounce" jump (jump right as you've landed right next to something) also feels like it sometimes works.
