Oops...forgot to mention...the wind resistance in the Y direction changes
sign after the fodder has started it's way down...so it would be the
opposite sign of the sign of the Y velocity:
Wy = Wy * -sgn(Vy)
Where Vy = Vy0 - g * t
R&R
> -----Original Message-----
> From: Steve Wood
> Sent: Friday, July 21, 2000 11:48 AM
> To: 'gda...@li...'
> Subject: RE: [Algorithms] interpolate between points in 3d space
>
>
> When a projectile is fired you should use it's trajectory
> equation. It sounds like you are entering the realm of
> physics. I'll give you a clue, but please pick up a book on
> newtonion physics, browse the web for physics stuff...there's
> been many references to physics web sites on this
> list...unfortunately we don't have an archive that goes back
> far enough right now that I know of. Maybe someone will post
> a link or two for you.
>
> Anyway for your particular example...let's add a mild
> constant wind resistance Wz and Wx along Z and X axis:
>
> X0 = initial X position of fodder after it leaves the cannon.
> Y0 = initial Y position of fodder after it leaves the cannon.
> Z0 = initial Z position of fodder after it leaves the cannon.
> Vx0 = initial velocity in X direction of the fodder after it
> leaves the cannon.
> Vy0 = initial velocity in Y direction of the fodder after it
> leaves the cannon.
> Vz0 = initial velocity in Z direction of the fodder after it
> leaves the cannon.
> Wx = constant wind resistance
> Wy = constant wind resistance
> Wz = constant wind resistance
> g = acceleration of gravity
> t = time with zero when the fodder leaves the cannon.
>
> X = X0 + Vx0 * t - Wx * t //X position
> Y = Y0 + Vy0 * t - Wy * t - .5g * t^2 //Y position
> Z = Z0 + Vz0 * t - Wz * t //Z position
>
> That's pretty much it, except you may want to use vector math
> instead of breaking it up into parts like I did. Did this
> answer your question?
>
> R&R
>
> > From: Anceschi Mauro [mailto:anc...@li...]
>
> > Hi.
> > I have a little problem in my 3D space game.
> > When my ship "fire" from a cannon i use a new local axis for
> > the new object i'm firing , for calculate the next point of
> the laser.
> > But this works bad, and i don't have much precision.
> > So my question is:
> > How can interpolate from 2 point in 3d?
> > (x,y,z) and (x',y',z') (suppose the second is an enemy ship).
> >
> > Thanks,
> >
> > mauro
>
|
