NPC navigation

[EIREXE]

NPCs need to be able to navigate around the world using the navigation mesh.

The navigation process is the following:

• Given a target position, a path is calculated that would get us there.
• The path is simplified, since that will make things like triangulation easier.
• To reach each point, a series of checks are done to make sure it is possible for us to reach it.

The navigation to each of the points of the path is known as a navigation step.

Movement checks

For each navigation step, we should do a series of checks, these include:

• Trying a simple hull cast, if we fail, try to change our target position a little bit to the sides to see if we can avoid it (triangulation).
• If an obstacle is found in the way, check if it's a low obstacle that we can just ignore (this is used for things such as stairs).
• If at the start of the navigation step we are too close to a wall, see if we can get away from it.

Status

• Triangulation
• Stair stepping
• Initial wall avoidance

References

• Half-Life 2 NPC Movement Part 1: Local Navigation (by pinsplash) https://www.youtube.com/watch?v=E42AomiAWis