Hi, I was wondering if there was an easy way to find the intersection of a sphere and a line using jptc api.

I want to translate an Object3D(object#1) from its original position to a given radius from the centre of another Object3D(object#2) but taking in count the object#1 direction (SimpleVector)
 


The idea is to travel from an object to a distance of another

 

I solved the flickering when keeping the finger still on screen by adding a simple if statement
line.set(-touchTurn, 0, touchTurnUp);
m = line.normalize(line).getRotationMatrix(m);
m.rotateAxis(m.getXAxis(), (float) -Math.PI / 2f);
if((touchTurn > 0.01f || touchTurn < -0.01f) || (touchTurnUp > 0.01f || touchTurnUp < -0.01f))
{
camera.moveCamera(Camera.CAMERA_MOVEIN, 50); // 50 is the distance from the cube's center that the camera has
camera.rotateCameraAxis(m.invert3x3().getXAxis(), -line.length() / 15f); // 5f actually depends on render speed
camera.moveCamera(Camera.CAMERA_MOVEOUT, 50);
touchTurn = 0;
touchTurnUp = 0;
}
now I just have to do the method that calculates the rotate camera angle depending on the frames per second or time passed to render the last frame, although I'm not sure of how I'm going to achieve this I'm trying with the fps approach but rotation suddenly accelerates : ( , I'll keep trying to get a reliable value for this (and constant) ; )

The movement of the camera is correct, that's the idea of how it should behave but its way too sensitive, I'm testing it in a nexus one.

I can see the comment "// 5f actually depends on render speed" so there should be a way of dynamically calculate it so it works the same in each device

Since there is unlimited ways of looking at something, I'm trying to set the camera relative to the camerapivot dummy
private void resetCameraPosition() {
camera.setPosition(cameraSatellite.getTransformedCenter());
camera.setBack(cameraPivot.getRotationMatrix().cloneMatrix().invert());
}
although it still doesn't feel right.

The problem I have implementing your method is that I'm not sure how to make it interact with touchTurn and touchTurnUp.

Ill upload the modified hello world if we can get this one right It will be very good example for the wiki which currently only has info about fps style camera

I'm also using the dummy approach but I have a strange behaviour.

when I rotate the pivot dummy all works until I get closer to the top (90º) of the rotation, if I use camera.lookAt(), the camera should be upside down if you pass the top of the rotation, but it always stays upright, that causes a very nasty feel.

I also thought about using camera.setOrientation(dir,up) but I cant get it right.

The goal is to achieve a camara that moves around the object at a constant 3d radius with the camera Oriented to the centre of the object with "the exact same feel as the helloWorld AE" but rotating and moving the camera instead of rotating the 3dobject with a fixed camera

Here Is what I tried so far:
private void resetCameraPosition() {
camera.setPosition(cameraSatellite.getTransformedCenter());
camera.lookAt(cameraPivot.getTransformedCenter());
}

private void initCamera() {

                //move the dummy pivot to the centre of the 3dobject
cameraPivot = Object3D.createDummyObj();
cameraPivot.translate(calcTrans(cameraPivot, 3dobject));

                //move the dummy satellite to the centre of the 3dobject and separated it by a radius (-20)
cameraSatellite = Object3D.createDummyObj();
cameraSatellite.translate(calcTrans(cameraSatellite, 3dobject));
cameraSatellite.translate(new SimpleVector(0, 0, -20));

                //Made child
cameraPivot.addChild(cameraSatellite);

camera = world.getCamera();
resetCameraPosition();
}

 
To turn the cameraPivot dummy I'm using the same code as in the AE helloWorld
if (touchTurn != 0) {
cameraPivot.rotateY(touchTurn);
resetCameraPosition();
// camera.rotateCameraY(touchTurn);
touchTurn = 0;
}

if (touchTurnUp != 0) {
cameraPivot.rotateX(touchTurnUp);
resetCameraPosition();
// camera.rotateCameraX(touchTurnUp);
touchTurnUp = 0;
}

I also tried several approaches for the resetCameraPosition() method, including getBack with invert, setOrientation etc etc. And none of them behaved as I would expect : (

Any idea of how to get this one right? Maby someone could do an example of the helloWorld using camera rotation instead of primitive cube rotation. It would be very handy.