@Flying Steel
You'll have to play with those settings, I don't think there's any real documentation. Units I would guess are based on quake units, but the easier way to understand is to play with them and look at default values and compare your changes, jump around to see what difference your changes did, look at the speedometer, etc. For most of those cvars you can't really think in terms of units because many depend on gravity or other things that influence each other (unless you are very good at math and can look at source code, maybe you can understand, but it's easier to play with values and move around maps you know well to get the "feel").
Usually, if you raise a value somewhere, you'll want to lower one somewhere else otherwise you'll get unwanted side effects (unless that's what you want
). Trying to come up with a new physics set is very time consuming because it requires a lot of testing to make sure it won't break maps. Sometimes you'll get something that seems to work perfect on small closed maps, but then on larger open maps they'll be way too fast or too slow, so it's a lot of testing and adjusting values.
Most of the cvars are self explanatory, they're either related to acceleration or maximum speed.
sv_maxspeed = maximum speed while on ground (that's the value you'll get on speedometer while walking in one direction on ground, you can go slightly over it by turning mouse very fast, depending on other values used by other cvars)
sv_maxairspeed = maximum speed while in air (this affects acceleration too, think of it as maximum speed you can gain in one jump)
sv_accelerate = acceleration on ground, affects how fast you can get to sv_maxspeed and also how fast you can change direction, along with sv_friction.
sv_airaccelerate = acceleration while in air, nothing much to explain, higher value means more acceleration
sv_friction = friction on ground, how much you "slide" when changing direction. Another cvar to check is sv_stopspeed
edgefriction = I guess friction when standing on an edge (never played with this, not sure)
sv_stepheight = how high a block can be before a player needs to jump to step on it (ie: the height of stair steps), changing this might break maps.
sv_jumpvelocity = how high player can jump, this dependent on sv_gravity and might break maps, best to stick to default unless you are changing gravity
sv_friction_on_land = never tried but I would guess how much slow down you get when landing after a jump or a fall and hit the ground
sv_airaccel_sideways_friction = hard to explain, but if set to 1, there's no speed gained by strafe jumping, and more speed gain if 0, but can act very weird depending on sv_airaccelerate.
sv_airaccel_qw = weird one, sometimes I think I understand what it does, and other times I have no clue.. it affects strafe jumping, but finding good values is very hard to find.. I wouldn't play with that one if I were you, it can mess things up. Default 0.95 value seems perfect, between 0.93 and 0.96 seems "okay" but anything else you get bad side effects and odd speedbursts.
Also, if you have svn you might wanna check the physics25.cfg file for new cvars that were added that can be used to adjust air control and other behaviors related mostly to bunnyhopping.
