Calculating an actor's total velocity

[ChronoSeth]

Can anyone think of a formula which will combine an actor's X, Y, and Z velocity to come up with it's overall velocity in ay given direction?
In case anybody's wondering, I'm was trying to make a melee weapon which deals increased damage based on the player's speed; but I hit a stall here. It wouldn't make much sense to have increased damage when you are running forward but not if you strike when falling.

[Edward-san]

Do you mean the norm of the velocity vector? If yes, then use this value: sqrt ( velx*velx + vely*vely + velz*velz )

[edit]whoops i failed to read the last sentence... so you don't need the velz thing. Just [ sqrt ( velx*velx + vely*vely) ].

[XutaWoo]

So don't factor in z velocity?

As for your question, it would probably be something akin to abs(velx)+abs(vely). (4*((abs(velx)+abs(vely))/40))+3 would do 3 damage minimum, 7-ish maximum. 40 is an assumption of the maximum player speed (with straferunning), so you'll need to adjust it if it isn't the default speed.

Alternatively, you could go with a lower divisor and remove the 4* to just get a straight value based on speed; just make sure it's divided by something, or else the weapon would get truly rediculous.

e:f;b, though I have another method.

[David Ferstat]

Seen this thread?

http://forum.zdoom.org/viewtopic.php?f=3&t=27567