Moving and rotating the cam

[bionicoz]

I'm sorry but I need your help another time. I'm writing a method that smooth move the cam to a point in the 3Dworld. For now it's frame based, and the trajectory and speed are linear.

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public void flyTo(SimpleVector s, float speed) {...}
The moving part seems to be ok

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SimpleVector whereIam = this.getPosition();
SimpleVector direction = s; //the point where I have to go
direction.sub(whereIam);
if (direction.length() > PROXIMITY) { //I stop PROXIMITY units before the point
this.moveCamera(direction, speed);
}

but I have problems with the rotating part.
using calcAngle() give me always positive result, so in i have to rotate 15° left, what happens is that I rotate 345° right. Is there a better way to do that? I think using rotation vector, but i don't clearly understand how do they works.
Ty as always,
Bio.

[EgonOlsen]

...so in i have to rotate 15° left, what happens is that I rotate 345° right

What's the problem with that as long as the outcome is the same?

[bionicoz]

The problem subsists because I do that step by step. All the information I get (but it's probably my fault) is that my position has an angle of, let's say, 15° with the destination, but calcAngle() tell me 15° even if the angle is 345°.
I rotate the cam with something like that

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this.rotateCameraAxis(this.getYAxis(), speed);
I would like to rotate with -speed if the angle is > of 180°.
Any suggestions?


 

[Kaiidyn]

im not sure, but could this be related to the fact that (im not sure though) the angles are not 0 - 360 but -180 - 180 ?

[bionicoz]

Hi, I solved with a really simple check:

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SimpleVector rotation=this.getDirection();
rotation.y=0; //I don't care about y angle, for now at least
rotation.normalize(rotation);

direction=s;
direction.y=0;
direction.normalize(direction);
float f=(direction.x-rotation.x); //This is the really clever check :D
float angle=direction.calcAngle(rotation);
if ( !(angle>-0.03f && angle<0.03f) ) {
   this.rotateCameraAxis(this.getYAxis(), Math.signum(f)*speed);
} else {
   this.turning = false;
}


Ty all for support.

EDIT: nope, isn't really working as expected :\

[Kaiidyn]

angle is in radians (correct word?) and not in degrees?

[EgonOlsen]

This thread deals with the same problem. Maybe it helps: http://www.jpct.net/forum2/index.php/topic,1762.0.html

[bionicoz]

That helped a lot, ty Egon.