Strafe jumping, physics, help

[Tonester]

Does anyone have an idea of how to model Quake's physics in UT? I'm not talking about code or anything... I can handle that part. I'm talking about the actual physics behind modeling the behavior.

The basics are easy:
You can queue up jump commands while in mid-air. If you press the jump button any time after leaving the ground and prior to landing on the ground, you'll queue up a jump command which gets executed as soon as you touch the ground.

If you jump within a certain amount of time after hitting the ground, you don't lose any speed... it is as if you can momentarily "cheat" friction if you jump quickly enough after landing.

In addition to above, if you strafe and look in the same direction while in the air, you can actually gain momentum/speed. But if you look too far or too little, you don't.

I can handle the jumping, ground friction, etc. My question is... how would one go about modeling the player's current state (speed vector) and how would one go about enacting impulses on this vector based on things like player input (strafe direction, look vector, their current speed vector, etc).

Any ideas?

[ameyp]

This is not physics, all of what you've mentioned comes under the "code" category
Look inside UTPawn, Pawn, UTPlayerController and PlayerController, most of what you want you will find there

[Tonester]

No offense - I've been coding in UE for several years now I found what I was looking for here:
http://www.funender.com/quake/articl...ng_theory.html

And yes, it's all physics.

Just have to add the ability to queue up jumps while in the air so that the player jumps immediately upon hitting the ground (to reduce ground friction). Also, it seems UT has a little bit of a recovery time upon landing so I'll have to remove that.

[ameyp]

Sorry, when you said physics I started thinking about rigidbodies and kactors :P

[Tonester]

Ahh - yea. Not UT physics but like... old high school physics

[Blade[UG]]

I've played every Quake game there ever was, and I've never noticed a queue of jumps ..

[Tonester]

I'm not sure about Q2 or QW but Q3 definitely had it. I just ran through some levels in Q3A last night to get a feel for things and that is one of the things I realized. You are just so used to doing it probably (like breathing) that you don't notice.

[hannes]

ive been working on this a bit lately. Im pretty new to the udk family so what i was doing was to calculate the velocity directly. UT uses an accel vector and then clamps the speed by groundspeed, which would conflict with a typical strafe movement.

For your jump stuff, i worte a little patch that gives the user a 200 msec timeframe to press jump before he actually touches the ground, so he can directly jump away again.

What ET (Q3) does, is just clipping the velocity and right / strafe vectors to the current movement direction + which then would result in this boost that you get from jumping down slopes. I could recode this, however my approach is far from useful, since i set the groundspeed each tick, to the calculated velocity. If you have had more success in the whole layout, id be more than pleased to hear back from you.


ps: that post MUST be super confusing, and i apologize for this now already, super tired :<

[loonatik]

So how far did you guys get on this? I am really interested in reproducing strafe jumping in my game.