vector3-query.cs

IQueryable<Powerup> PowerupsAroundLocation(Vector3 location, float radius)
{
    // Note that this query returns a cube around the location, not a sphere.
    var powerups = realm.All<Powerup>().Filter(
        "Position.x > $0 AND Position.x < $1 AND Position.y > $2 AND Position.y < $3 AND Position.z > $4 AND Position.z < $5",
        location.x - radius, location.x + radius,
        location.y - radius, location.y + radius,
        location.z - radius, location.z  + radius);
}