Ehsan Kamrani

10-23-2005, 03:53 AM

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-

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-