Author Topic: Whats wrong with my collision detection  (Read 2897 times)

Offline Melssj5

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Whats wrong with my collision detection
« on: September 04, 2005, 03:24:53 am »
Hi, I have not used the engine in ages, so 2 days ago I began to do little project, but I just cant do the collision detection.

When I thought that it was good, I noticed that it didnt worked on the corners, I tried with other ways, but now the camera moves very quickly and no matter the speed I set.

here is my code for managing the events taken from the KeyState

Code: [Select]

public void movimientos () {
       
        boolean piso=false;
        try {
            if (Mundo.checkCameraCollision (new SimpleVector (0, 1, 0), alturaPersonal, alturaPersonal, false))
                piso=true;

            if (adelante)
                if (Mundo.checkCameraCollision (camaraPersonal.getDirection (), alturaPersonal, alturaPersonal, true))
                    camaraPersonal.moveCamera (Camera.CAMERA_MOVEIN, velocidadPersonal);

            if (atras)
                if (Mundo.checkCameraCollision (camaraPersonal.getDirection (), alturaPersonal, alturaPersonal, true))
                    camaraPersonal.moveCamera (Camera.CAMERA_MOVEOUT, velocidadPersonal);
           
            if (izquierda) camaraPersonal.rotateAxis(camaraPersonal.getBack().getYAxis(), -0.02f);
           
            if (derecha) camaraPersonal.rotateAxis(camaraPersonal.getBack().getYAxis(), 0.02f);
           
            if (salto)
                if (Mundo.checkCameraCollision (Camera.CAMERA_MOVEUP, alturaPersonal, alturaPersonal*4/3, true))
                    camaraPersonal.moveCamera (Camera.CAMERA_MOVEUP, velocidadPersonal);
           
            if (agache) camaraPersonal.moveCamera (Camera.CAMERA_MOVEDOWN, velocidadPersonal/2);
            if (salida) System.exit (0);
        }
        catch (Exception E) {
           
        }
    }


Well, the gravity done on the second line works good, the problem is when moving the camera to the front and back.

If I have to use another kind of collision detection please could someone explain me why and how?.
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Offline EgonOlsen

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Whats wrong with my collision detection
« Reply #1 on: September 04, 2005, 12:42:23 pm »
Don't use checkCameraCollision()...it's ancient stuff that doesn't work well in all cases. I strongly suggest to use checkCameraCollisionEllipsoid instead. Have a look at the fps example to see how to.

Offline Melssj5

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I did it
« Reply #2 on: September 06, 2005, 09:15:58 am »
Well, after 24 hours breaking my soul I did it.

The collision detection really brang me troubles, I just couldnt understand why does my Colli... didnt worked. It result being easy, the problem was that as the checkCameraCollisionEllipsoid and the checkCameraCollisionSpherical return a boolean depending if they collide or not, I thought that the methods only returns the result of CHECKING for a collision, but in fact they do more than that. They also move the camera, thats why I was moving the camera more than once for every movement. And also the speed have to be set in that method.

A suggestion is to do a method that only checks for a collision, it may be useful, when I learned programming in java (a year ago), I learned that a method should do only its specific task, thats why when I read the name of the method checkCameraCollision......, I thought that it only checks it.

Well, its just my opinion.
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Offline EgonOlsen

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Whats wrong with my collision detection
« Reply #3 on: September 06, 2005, 10:39:20 am »
Sorry for confusing you with the methods' naming.  In earlier versions, naming was different (something like moveCameraCollision IIRC, which was bogus too). But i agree that the naming is not that good. I just couldn't come up with anything better at that time and now...now i'll leave it this way... :wink:

Offline EgonOlsen

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Re: I did it
« Reply #4 on: September 06, 2005, 10:49:26 am »
Quote from: "Melssj5"
A suggestion is to do a method that only checks for a collision, it may be useful.
It is there. checkCollisionEllipsoid does exactly that. Again, the fps example should help to clarify this.