RVO Obstacle may cause array: Pathfinding.RVO.Simulator.WorkerContext.vox overflow

When i trying to use rvo obstacle system with lots of rov obstacles, it always crash, but it works fine with few rvo obstacles. I debug the code and found that there is a array overflow bug at: Pathfinding.RVO.Sampled.Agent.CalculateVelocity.

if (context.vos.Length < neighbours.Count+simulator.obstacles.Count)
      context.vos = new VO[Mathf.Max(context.vos.Length*2, neighbours.Count+simulator.obstacles.Count)];

which the “vertex count of obstacles in total” should be used instead of obstacles count, something like this:

// Fix array overflow bug.
if (context.vos.Length < neighbours.Count + simulator.ObstaclesVertexCount)
      context.vos = new VO[Mathf.Max(context.vos.Length * 2, neighbours.Count + simulator.ObstaclesVertexCount)];

“ObstaclesVertexCount” is the total vertex count with all of the obstacles.
In my temportary solution, i add a “vertexCount” for “ObstacleVertex”, in order to hold the total vertex count if the node is head of the obstacle list.
Add “obstaclesVertexCount” for Simulator.
Something like this in AddObstacle:

public ObstacleVertex AddObstacle (Vector3[] vertices, float height, Matrix4x4 matrix, RVOLayer layer = RVOLayer.DefaultObstacle) {
    if (vertices == null) throw new System.ArgumentNullException("Vertices must not be null");

    if (vertices.Length < 2) throw new System.ArgumentException("Less than 2 vertices in an obstacle");

    ObstacleVertex first = null;
    ObstacleVertex prev = null;

    bool identity = matrix == Matrix4x4.identity;

    //Don't interfere with ongoing calculations
    if (Multithreading && doubleBuffering) for (int j = 0; j < workers.Length; j++) workers[j].WaitOne();

    for (int i = 0; i < vertices.Length; i++) {
        ObstacleVertex v = new ObstacleVertex();
        if (first == null)
            v.vertexCount = vertices.Length;
            first = v;
            v.vertexCount = 1;
            prev.next = v;

        v.prev = prev;
        v.layer = layer;

        //Premature optimization ftw!
        v.position = identity ? vertices[i] : matrix.MultiplyPoint3x4(vertices[i]);

        //v.thin = thin;
        v.height = height;

        prev = v;

    prev.next = first;
    first.prev = prev;

    ObstacleVertex c = first;
    do {
        Vector3 dir = c.next.position - c.position;
        c.dir = new Vector2(dir.x, dir.z).normalized;

        c = c.next;
    } while (c != first);

    obstaclesVertexCount += vertices.Length;

    return first;

Hi @aron_granberg, maybe you can check this out at some time.


I think this has been fixed in the beta version.

Thanks Aron! I am current working on 3.8.1 and upgraded to 3.8.2, have not used beta version before, i will check it out later.