// This is a lot of complex math on choosing some "random" movement, keeping it near home and handling error cases.
private void Movement(float speed, float chaos)
{
// Initialize a random number generator.
Random rng = new Random();
// Pick a direction to start with - mostly in the X/Y plane, but just a little push up.
Direction = new Sansar.Vector((float)(0.5 - rng.NextDouble()), (float)(0.5 - rng.NextDouble()), 0.02f, 0.0f);
// This will just continually try to move the object (the Wait at the bottom is important!)
while (true)
{
// Calculate how far we are from our home point.
float distance = (RigidBody.GetPosition() - Home).Length();
// Pick a new direction based on Chaos level, or if we have wandered off too far
if (rng.NextDouble() <= Chaos || distance > Range)
{
// If we are far from home point us at home before adjusting the position.
if (distance > Range)
{
// Move toward the center.
Direction = (Home - RigidBody.GetPosition()).Normalized();
// Note: still letting the randomize adjust the heading.
}
// This is the most bogus direction adjusting logic you will see today.
Direction.X = Direction.X + (float)(0.5 - rng.NextDouble());
Direction.Y = Direction.Y + (float)(0.5 - rng.NextDouble());
Direction.Z = 0.02f;
Direction = Direction.Normalized();
}
// AddLinearImpulse can be picky on accepted values, especially if any math above breaks or the speed is set too high.
// It will throw an exception if it doesn't like it. This will just skip
try
{
Log.Write("PUSH! " + Direction.ToString() + " * " + speed + " => " + (Direction * speed).ToString());
RigidBody.AddLinearImpulse(Direction * speed);
}
catch (Exception e)
{
Log.Write("Exception " + e.GetType().ToString() + " in AddLinearImpulse for value: " + (Direction * speed).ToString());
// That direction was bad, so lets choose a new one.
Direction.X = (float)(0.5 - rng.NextDouble());
Direction.Y = (float)(0.5 - rng.NextDouble());
Direction.Z = 0.02f;
Direction = Direction.Normalized();
}
// Wait after each push for between 0.5 and 1.5 seconds.
Wait(TimeSpan.FromSeconds(0.5 + rng.NextDouble()));
}
}
// Putting the collision event into a coroutine helps to reduce duplicate events
// After every collision we give a small bump then sleep this coroutine before waiting on another collision.
// An Action event handler would get a large queue of events for colliding with the same object which is harder to deal with.
private void CheckForCollisions()
{
while (true)
{
// This will block the coroutine until a collision happens
CollisionData data = (CollisionData)WaitFor(RigidBody.Subscribe, CollisionEventType.AllCollisions, Sansar.Script.ComponentId.Invalid);
if (data.HitObject == null)
{
// This is slightly more common, collided with something were no object was given from the physics system.
// Again, just sleep a little and continue.
Log.Write("Hit nothing? " + data.HitComponentId);
Wait(TimeSpan.FromSeconds(0.2));
continue;
}
// This position - collision object position gives a vector away from the object we collided with.
// This is not "away from the collision point". Complex shapes or large objects will confuse this simple math.
Sansar.Vector direction = ObjectPrivate.Position - data.HitObject.Position;
direction = direction.Normalized();
if (Math.Abs(direction.X) < 0.1 && Math.Abs(direction.Y) < 0.1)
{
// This object is mostly above or below us: it is probably the floor.
// This is overly simplistic and will fail for large objects or sloped floors.
// Sleep a little and continue.
Wait(TimeSpan.FromSeconds(0.2));
continue;
}
// direction is now pointing _away_ from what we collided with, set it as our Direction for Movement.
Direction = direction;
try
{
// Apply an immediate bump away from what we collided with.
Log.Write("Bump! " + Direction.ToString() + " * " + Speed + " => " + (Direction * Speed).ToString());
RigidBody.AddLinearImpulse(Direction * Speed);
}
catch (Exception e)
{
Log.Write("Collision Exception " + e.GetType().ToString() + " in AddLinearImpulse for value: " + (Direction * Speed).ToString());
}
// Wait before checking for more collisions to avoid duplicate collisions and give a chance to separate from the other object.
Wait(TimeSpan.FromSeconds(0.2));
}
}
