function filter(p) {    
    
    /* Filter in which you define a zone that no entites can enter */
    /* Default box coordinates correspond to stage area in dev-demo */
    if (p.position) {
        /* Define the points that create the "NO ENTITIES ALLOWED" box */
        var BigStageMin = {x: 90, y: -1, z: 23};
        var BigStageMax = {x: 109, y: 10, z: 30};
        var ProceniumMin = {x: 97.5, y: -1, z: 30};
        var ProceniumMax = {x: 102, y: 5, z: 33.5};
        /* Define the point that you want entites that enter the box to appear */
        var resetPoint = {x: Math.random() * (103.6 - 95.4) + 95.4, y: 2.5, z: 38.1557};
        /* Random near-zero value used as "zero" to prevent two sequential updates from being
        exactly the same (which would cause them to be ignored) */
        var x = p.position.x;
        var y = p.position.y;
        var z = p.position.z;
        if (((x > BigStageMin.x && x < BigStageMax.x) &&
            (y > BigStageMin.y && y < BigStageMax.y) &&
            (z > BigStageMin.z && z < BigStageMax.z)) ||
            ((x > ProceniumMin.x && x < ProceniumMax.x) &&
            (y > ProceniumMin.y && y < ProceniumMax.y) &&
            (z > ProceniumMin.z && z < ProceniumMax.z))) {
            p.position = resetPoint;
            if (p.velocity) {
                p.velocity = {x: 0, y: 0, z: 0};
            }
            if (p.acceleration) {
                p.acceleration = {x: 0, y: 0, z: 0};
            }
        }
    }

    return p;
}