Conditions & Effects

Conditions

Conditions are essentially the prerequisites or requirements that need to be met for an action to be executed. They are tied to the game's state, represented by WorldKey.

• Key: This is the WorldKey that the condition checks. Think of it as a variable or a state in the game world, like "PlayerHealth" or "HasAmmo."

• Comparison: This is how the WorldKey is compared to a specific value to determine if the condition is met. The available comparisons are "SmallerThan," "SmallerThanOrEqual," "GreaterThan," and "GreaterThanOrEqual."

• Value: This is the specific value that the WorldKey is compared against using the specified comparison.

For example, a condition might be set up like this:

• Key: PlayerHealth

• Comparison: GreaterThan

• Value: 50

This condition checks if the player's health is greater than 50.

Effects

Effects describe the changes that an action brings about in the game's state, again represented by WorldKey.

• Key: This is the WorldKey that the effect modifies. For instance, "PlayerHealth" or "AmmoCount."

• Type: This indicates whether the WorldKey value will increase or decrease as a result of the action.

For instance, an effect might be:

• Key: AmmoCount

• Type: Decrease

This effect would decrease the ammo count when the action is executed.

Matching Conditions and Effects

The system matches conditions and effects to determine the sequence of actions that lead to a goal. Here's how the matching works based on the provided documentation:

• SmallerThan and SmallerThanOrEqual comparisons in conditions look for actions with negative effects. This means if a condition requires a WorldKey to be less than a certain value, the system will look for actions that decrease that WorldKey.

• GreaterThan and GreaterThanOrEqual comparisons in conditions look for actions with positive effects. So, if a condition requires a WorldKey to be greater than a certain value, the system will search for actions that increase that WorldKey.

For example, if there's a condition that checks if "AmmoCount" is SmallerThan 5, the system might look for an action with a negative effect on "AmmoCount" (like "ShootBullet"). Conversely, if the condition checks if "AmmoCount" is GreaterThan 10, the system might look for an action with a positive effect on "AmmoCount" (like "ReloadGun").

In essence, the GOAP system uses these conditions and effects to build a graph of possible actions and sequences, which is then used by the planner to determine the best course of action to achieve a goal.

Examples

Setting conditions and effects through code.

Creat

var builder = new GoapSetBuilder("GettingStartedSet");

builder.AddAction<ShootBullet>()
           .AddCondition<AmmoCount>(Comparison.GreaterThanOrEqual, 1)
           .AddEffect<AmmoCount>(false)

Setting conditions and effects through the inspector.

action-config.png