How does an object's position become invalid?

I have an error 'transform.position assign attempt for 'CharacterController' is not valid. Input position is {NaN, NaN, NaN}. When this happens the character gets 'stuck' and no long responds to input. What script mistakes in general might lead to an invalid position?

 

You would need to provide some script. It would be just guessing at the answer without it.

 

Is there a certain spot where you get stuck? Try adjusting the character controller properties a bit.

 

Some how you are setting your values to infinite, or the square root of -1(or any negative number).
Edit: Also 0 / 0(which is infinity) produces NaN as well
http://msdn.microsoft.com/en-us/library/system.single.nan.aspx

 

As a possible solution, at the end of the Update function in my control script I put:
if(transform.position.x == Mathf.Infinity)
{
transform.position.x = 999999;
}
if(transform.position.y == Mathf.Infinity)
{
transform.position.y = 999999;
}
if(transform.position.z == Mathf.Infinity)
{
transform.position.z = 999999;
}
if(moveDirection.x == Mathf.Infinity)
{
moveDirection.x = 999999;
}
if(moveDirection.y == Mathf.Infinity)
{
moveDirection.y = 999999;
}
if(moveDirection.z == Mathf.Infinity)
{
moveDirection.z = 999999;
}

So far, I hadn't ran into the error again yet, but I'm not sure if it's just by chance or if I created an exception handler that works.

 

That would solve the issue, but there are better ways. If you show your movement code maybe we could help you avoid that, as it's a workaround more than a real solution, and then you won't run into it again.

Edit: Also, if it's 0/0 that's causing it, rather than just rapid movement, you could find yourself teleporting about.

 

Infinity isn't the same as NaN. NaN is not equal to any value, even NaN. I think Ntero is right, somewhere a 0/0 or square root of a negative number has happened and been applied to a variable in your transform. Maybe you used Quaternion.AngleAxis with a zero length vector. That's just a guess but maybe something like that.

 

Yeah My mistake NaN, does not include +/- Infinity, so that solution won't actually work at all. If you show some code it should hopefully be quick to spot the culprit.

 

I think the problem is here:
var right = Vector3(forward.z*MainCameraScript.CamDist(), 0, forward.x*MainCameraScript.CamDist());

CamDist() is a function in a script I'm referencing that is:
function CamDist()
{
var DistRev : float;
DisRev = (50 - currentDistance)/10;
return DisRev;
}

I used the function set the 'turning' to be relative to how far the camera is
from the player. It's for when the character is in a vehicle. I have the max distance to be
no greather than 40, but there may be moments when it will be higher for a split second.