How to calculate change speed of a value

vvvv beta general
1

Hi,

Let’s say I have a value which represents the X coordinate of a point in space. I want to find it’s speed when it changes.

My problem is that I guess I must save the previous X value and the amount of elapsed time to compare the two values and calculate velocity.

Since in MAX messages happen from right to left I can do things in order: first compare current value with last value, then save this value which will be next time’s previous value.

But in vvvv, since everything happens at the same time, I don’t know how to accomplish this.

Can anyone help me?

UPDATE: I just found the “Damper” object by chance and found out that it can calculate velocity and acceleration of an input value. I’m not sure if I can use it, though, since its outputs depend on a delay time. But even if this solves my problem I’m still curious about how to build this.

Thanks!
Nuno

2

there are the nodes FrameDifference (Animation) and FrameVelocity (Animation) for that purpose… also try Heading (Animation)

3

Thank you! Perfect!