# Moving the objects in 3d space

Hi
I want to move an object in 3d space. The object should move on a curve with a constant velocity. My problem is that if i use from the following function:
R(t) = x(t) i + y(t) j + z(t) k = sin(t) i + j + 2*t k

Then the vector function is:

v(t) = d R(t) / dt = dx(t)/dt i + dy(t)/ dt j + dz(t) / dt k = cos(t) i + 0 j + 2 k

So | v | is:
sqrt( cos^2(t) + 0 + 4 ) = sqrt( 4 + cos^2(t) ).
As you see, | v | is not constant–it changes with time…

This is an example. There are many example that | v | is not a constant value. So what should i do?How the programmers solve such a problem?
Regards
-Ehsan-

Well I haven’t looked at your equation, but you might find some that depends on the speed so that you can ensure it’s always the same speed.

He Eshan,
my suggestion for this problem would be the following:
dt := time interval
t := total time intverals elapsed
v(dt) := movement per time invterval
now
pos(t+td) = pos(t) + v(dt)
This just came to my mind when I read your post, but i hope it helped you a little bit Greetz
Toni