Seek Steering Behavior (AI)

[Metro_Mystery]

Homework Statement

I'm having trouble understanding the physics equations related to Steering Behaviors For Autonomous Characters (present in the book "Programming Game AI by example").

For those that don't know- Seek is a kind of behavior whereby an object with a given mass, current position & velocity attemps to seek to a target position.

Homework Equations

In the book, Mat Buckland calculates Seek like so (in Pseudocode)

def Seek()
DesiredVelocity = Normalize(TargetPos - VehiclePos) * VehicleMaxSpeed
SteeringForce = DesiredVelocity - VehicleVelocity
return SteeringForce

The Attempt at a Solution

Seek is stated, in the book- to return a steering force, which is "the force required, when added to the agents current velocity vector, gives the desired velocity. He calculates it like this:

How does the subtraction of two velocity vectors suddenly become a force?

My heads in a spin- any help is greatly appreciated!

 

[AvroArrow]

The subtraction of two velocity vectors does not result in a force. The equation provided by the book simply calculates the desired velocity, which is the vector that the agent should move towards in order to reach its target position. The SteeringForce calculation then subtracts the current velocity from the desired velocity, resulting in the necessary force that needs to be applied in order to reach the desired velocity.

 

[Moetasim]

As a scientist, my response would be to first clarify that the equations and concepts in the book are based on simplified models and assumptions, and may not accurately reflect real-world physics. It is important to keep this in mind when trying to understand the calculations.

In the context of AI, "force" is used as a term to represent the desired direction and magnitude of movement for an agent. It does not necessarily represent a physical force in the traditional sense.

In the Seek behavior, the subtraction of two velocity vectors is used to calculate the desired direction of movement towards the target position. This desired direction is then combined with the agent's maximum speed to calculate the desired velocity. The difference between this desired velocity and the agent's current velocity is then used as the steering force, which will ultimately determine the agent's movement towards the target.

It may be helpful to think of the steering force as a "guidance" or "instruction" for the agent, rather than a literal force. This approach is commonly used in AI and computer simulations, and while it may not align with traditional physics concepts, it is a useful tool for achieving desired behaviors in autonomous characters.

If you are still having trouble understanding the equations, I would recommend seeking further clarification from the book's author or consulting additional resources on the topic. It is also important to practice and experiment with the equations to gain a better understanding of how they work in practice.