Chapter 3 Part 2

Front 1

You can use a cone detection field to accomplish what?

Back 1

Collision avoidance

Front 2

Write cone detection code

Back 2

if (orientation.asVector().direction > coneThreshold {

# do the evasion

else

# return no steering

Front 3

What is one of the problems with the cone detection method of collision avoidance?

Back 3

Objects must be represented as spheres for it to work which is inaccurate if working with hard and fast objects like walls.

Front 4

How does ray casting collision avoidance work?

Back 4

Character casts a single ray out in direction of movement; if there is a collision, a new target is generated that will not result in a collision and character does seek behavior towards that.

Front 5

Why does ray casting require more than one ray?

Back 5

If only one ray we may not accurately detect collisions, such as grazes along the side of the characters path.

Front 6

What is the corner trap?

Back 6

Characters approaching an (outside!) corner will detect one side of the corner and move to avoid, and will then detect the other side of the corner. The character will alternate until it collides with the corner and is unable to extricate itself.

Front 7

What is the only complete solution for collision avoidance?

Back 7

A collision projected volume

Front 8

Why do we need to combine steering behaviors?

Back 8

To create sophisticated movement that can do multiple things

Front 9

What is blending in the context of steering behaviors?

Back 9

Creating a weighted average of the different steering forces, with the weights representing priority.

Front 10

What is an arbitration in the context of steering behaviors?

Back 10

Giving one steering behavior complete control; there are many different arbitration schemes.

Front 11

What three steering forces does flocking combine?

Back 11

Velocity matching, collision avoidance, cohesion

Front 12

How is priority based behavior combining implemented?

Back 12

Similar steering behaviors are organized into groups, and these groups are prioritized. So for example, collision avoidance might be more important than seek behaviors.

Front 13

What do the groups in priority based behavior combining return?

Back 13

They return a net acceleration representing the weighted average of the steering behaviors in that group.

Front 14

What are variable priorities?

Back 14

Variable priorities means our groups of steering behaviors can change their priority as conditions change.

Front 15

Priority is good for combining behaviors when:

Back 15

You have many, many different steering behaviors to implement.

Front 16

What is formation motion?

Back 16

Movement of a group of characters so they retain some sort of formation

Front 17

What is the simplest kind of formation motion? How is it represented?

Back 17

The simplest kind is fixed formation; characters have allocated slots where they should go.

Front 18

What is the "leader-slot" in fixed formation motion?

Back 18

The leader slot is the position "0" that the other slots are positioned relative to.

Front 19

Which slot controls movement in fixed formation? Does it know about the other things in the formation?

Back 19

The leader slot character controls movement; it is not aware of the other characters in the formation.

Front 20

For movement of a non-leader slot character in fixed formation, why do we not need kinematics and steering?

Back 20

We know exactly where the character should be relative to the leader slot character, which does know the kinematics and steering.

Front 21

Does the character in the leader slot need more or less constraints on its movement than an independent character?

Back 21

More; while the leader does not know of the formation, it needs to act in a way that works with the formation, so for instance, it should have a lower speed.

Front 22

What is scalable formation? How does it differ from fixed?

Back 22

Scalable formation uses a function to add and move slots as more characters are added. These formations do not need an explicit initial list of slots.

Front 23

What is an emergent formation?

Back 23

Characters have no predefined spots; instead they seek out positions that the other members of their group have not target yet and do arrive behaviors towards those spots, according to rules.

Front 24

What is two level steering formation?

Back 24

Combines fixed and emergent by making the fixed slots the targets of the arrive seeks for each character!

Front 25

Describe slot roles

Back 25

Each slot can have a certain role of character to fill it.

Front 26

What is a hard role?

Back 26

A hard role for a slot means the slot can only ever be filled by a role.

Front 27

What is a soft role?

Back 27

A soft role means characters are assigned to slots based on their "slot cost". They don't need to be a perfect fit, the overall cost of the formation just needs to be minimized.

Front 28

How can we implement tactical movement with formations?

Back 28

As the game state changes, the desired formation can change to fit things like cover, shooting spots, etc.

Front 29

How is the tactical movement formation obtained?

Back 29

1)Get list of cover points in the game

2) Choose closest set of cover points to the formations anchor point (leader?)

3) When asked to say where a slot location is, choose from that set.

Front 30

What is the overwatch formation?

Back 30

Formation where characters will take turns covering eachother from cover positions, and moving up to the next position (leap frogging)