_speed at null

[Doh-a]

Hi,

using unitySteer for my project (lots of bugs running in a scene), I had some troubles with this version (used an older one, but I really need this optimized one).

If the speed of the vehicle is null at first, when we calculate the Velocity : return Transform.forward * _speed; (line 34)

we get a NaN;

So I changed the _speed from the initialization in the code (line 14), this is probably not the best solution, and I think I have this error due to a bad usage of your class. But this works for me. Is there a better way to do this ?

[ricardojmendez]

Which vehicle are you using - Autonomous or Biped? I expect autonomous, given your mention of _speed, but how can that value be null? It's a float, and value types cannot be null.

Please elaborate.

[Doh-a]

Sorry about the lack of precision.

Yes it's an autonomous Vehicle (it's for some kind of bugs, so I think this is the best in my case).

You are right _speed is not null, it's at NaN. I cannot explain why.

In the Velocity I put this lines :

Debug.Log("speed : " + _speed);
Debug.Log("forward : " + Transform.forward);
return Transform.forward * _speed;

And I get two kind of outputs. One which is good : speed : 0 forward : (0.0, 0.0, 1.0)

And one which is not : speed : NaN forward : (-0.2, -0.1, 1.0)

Which of course got a :

rigidbody.position assign attempt for 'walkingBug(Clone)' is not valid. Input position is { NaN, NaN, NaN }.
UnityEngine.Rigidbody:MovePosition(Vector3)
TickedVehicle:ApplySteeringForce(Single) (at Assets/AlterfaceProject/scripts/UnitySteer/Behaviors/TickedVehicle.cs:268)

I'm still looking for a good explanation about this. And in particular why some times I've got a speed at 0 and some time at NaN. Unfortunatly I didn't manage to find out. I never change the speed by myself (anyway this is an internal value).

After some others tests.

If I changed the declaration, in order to init the value like that :

float _speed = 0.0f;

I got the same problem which make sens, this is the same thing than float _speed; (http://msdn.microsoft.com/en-us/library/83fhsxwc.aspx)

But if I change the init value to :

float _speed = 0.1f;

I got no error at all.

A final test to be really sure. I changed a little bit the CalculatePositionDelta like this :

protected override Vector3 CalculatePositionDelta(float deltaTime)
    {
        if(System.Single.IsNaN(_speed))
            return new Vector3(0,0,0);
        else
            return Velocity * deltaTime;
    }

Of course I get no error, wich mean the trouble is really that _speed is at NaN. But this is like killing the messenger, it was just a test to be sure.

I'm probably missing a simple thing, but I'm not able to find what.

[ricardojmendez]

If you look at the AutonomousVehicle code, you'll see that the only place where _speed is set is on the Speed setter, and the only thing that does is a perform a clamp of the value passed with MaxSpeed. I suggest you add some Debug.LogError in the care of either being a NaN, along with a stacktrace, right about here:

https://github.com/ricardojmendez/UnitySteer/blob/development/Behaviors/AutonomousVehicle.cs#L22

[ricardojmendez]

Closing until we get more details.