How To Implement Arriving Behavior With Time Delta?

I'm trying to create an autonomous agent with arriving behaviour based on Reynolds classic Boids paper and more specifically Dan Shiffman's implementation on natureofcode.com. Both

Solution 1:

EDIT: I missed the main part of your question. There are many ways to get the result you want, but they do so by different means. The easiest I can come up with is probably to skip the steeringForce for now all together and instead just modify the velocity.

We want a vector such that

desired_velocity = velocity + correction

This is the same as you wrote previously (but for 'steeringForce'):

correction = desired_velocity - velocity

By doing velocity + correction you will immediately get to the desired velocity, which is usually not what you want as it leads to a very jerky motion. Instead, you could clamp the correction to some value which would lead to a smoother motion:

len = length(correction)
corr_length = len > max_correction ? max_correction : len
correction = correction/len*corr_length

And now you can do

velocity += correction

This should lead to a somewhat dynamic motion, without oscillation.

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Explicit time step integration (e.g. an forward Euler in your case) is usually written as

new_acceleration = old_acceleration + (delta_t/mass)*force
                                              ^^ note

And similarly,

new_velocity = old_velocity + delta_t*acceleration
new_position = old_position + delta_t*velocity

So to answer your question, you need to multiply by the time step before accumulating:

acceleration.add(force.mult(delta_t/mass));
velocity.add(acceleration.mult(delta_t));
location.add(velocity.mult(delta_t));