Some performance notes/tips when using Behavior Designer 1.6.3 Asynchronous Loading

I've finally got to the point in my game project where I need to start optimzing things. As I have been I noticed that when I was enabling 10-20 enemies at a time during the game(think Monster Closets) the game was freezing for a few frames. I checked the profiler and when my Behavior Trees were being enabled they were generating 20 mb of Garbage(GC) and causing a 460ms hit to the frame rate 0_0

I upgraded to Behavior Designer 1.6.3 as it has an Asynchronous loading of trees- I tried it out and got some errors. As of right now it seems Async Loading throws errors on some Movement Pack tasks- here is how to fix those errors. The errors are caused by some initializion code in those tasks not being thread safe. Anyway its a simple fix.

You have to change the following tasks- CanSeeObject, WithinDistance, Search

On CanSeeObject make line 24 look like this-

public LayerMask ignoreLayerMask;

line 49 like this-

private int ignoreRaycastLayer;

and add this on line 50 or 51-

public override void OnStart()
{
           base.OnStart();
           ignoreRaycastLayer = LayerMask.NameToLayer("Ignore Raycast");
}

On WithinDistance make line 26 look like this-

public LayerMask ignoreLayerMask;

Delete line 119

On Search make line 28 look like this-

public LayerMask ignoreLayerMask;

That should do it!

Here's a chart showing the performance improvements in my game loading a group of enemies during gameplay-

As you can see just using Async loading gives a huge performance boost- here's how to get more using Mec (More Effective Coroutines) which is a free on the asset store.

What I did was very simple- I add all my Enemies with Btrees to a list- then to activate them I loop through the list and wait a single frame between activations like so- here's a simple example of what I did-

 IEnumerator<float> _DelayedActivation()
    {
        for (int index = 0; index < EnemySpawns.Count; index++)
        {
            var i = EnemySpawns[index];

            ActivationProcess(i);
            yield return Timing.WaitForOneFrame;           
         }

        yield break;
      }

In Summary- using Async Loading in Behavior Designer gives you a huge boost + waiting a frame between loading your enemies/agents using a tool like MEC that doesn't generate garbage helps too. I've read about pooling external behavior trees for performance gains but haven't tried that yet.