How to get a random point on NavMesh?

Questions & Answers
1

Hi to all,

In my current project i use unity navmesh for ai navigation.i want my npc’s be able to get a random walkable destination(point) on navmesh and flee to that point when he/she see the player.
Any help or tips on how to do it, I’d be grateful.

2

This might not be the best way to do it but it worked for my purpose.

I generated a random point with in a unit sphere and multiplied it by the max distance I wanted my agents to walk:

Vector3 randomDirection = Random.insideUnitSphere * walkRadius;

I then added my agents current position to this vector and used the NavMesh.SamplePosition function to find the close position on the NavMesh:

randomDirection += transform.position;
NavMeshHit hit;
NavMesh.SamplePosition(randomDirection, out hit, walkRadius, 1);
Vector3 finalPosition = hit.position;

I then used final postion as the destination for my agent.

Hope this helps!

3

Thanks for the answer Valkyr_x! Expanding on that here’s a C# function for getting a random Vector3 Navmesh Position:

public Vector3 RandomNavmeshLocation(float radius) {
        Vector3 randomDirection = Random.insideUnitSphere * radius;
        randomDirection += transform.position;
        NavMeshHit hit;
        Vector3 finalPosition = Vector3.zero;
        if (NavMesh.SamplePosition(randomDirection, out hit, radius, 1)) {
            finalPosition = hit.position;            
        }
        return finalPosition;
    }

And this can make the NavAgent move by calling this code, with whatever radius you want:

myNavAgent.SetDestination(RandomNavmeshLocation(4f));