Libgdx相机使用EulerAngles在中心点上旋转

Question

Here is my code:

private Quaternion getRotatedQuaternion(float pitch, float yaw, float roll) {
    tempQuat.setEulerAngles(pitch, yaw, roll);
    rotationQuat.mulLeft(tempQuat);

    return rotationQuat;
}

and

            camera.view.setToLookAt(tempPos, tempLookat, Axis.UP);

            Quaternion rotQuat = getRotatedQuaternion(gestureListener.getXAngle(), gestureListener.getYAngle(), 0);
            camera.view.rotate(rotQuat);
            camera.combined.set(camera.projection);

            Matrix4.mul(camera.combined.val, camera.view.val);

This is a camera rotation in the center, on 0,0,0. Gimbal lock probleme solved by this way. But how can I add a new center point to it?

Basically I want to rotate the camera around my object, not 0,0,0

Thanks

Answer 1

I think the only way you could do that is to first, move the camera to the object's position, rotate, and move the camera back to the original spot.

So something like:

Camera.setposition(object.pos)
Camera.rotate()
Camera.setposition(original-camera-pos)

Answer 2

You need to convert from Polar Coordinates (r,θ) to Cartesian Coordinates (x,y) the formula is the following:

x = r × cos( θ )

y = r × sin( θ )

The angle is relative to your object central point (0º to 360º), the radius is the distance from your object to your camera.

Here's a simple method that does that for you:

public static Vector3 returnPosArroundObj(Vector3 posObject, Float angleDegrees, Float radius, Float height) {
    Float angleRadians = angleDegrees * MathUtils.degreesToRadians;
    Vector3 position = new Vector3();
    position.set(radius * MathUtils.sin(angleRadians), height, radius * MathUtils.cos(angleRadians));
    position.add(posObject); //add the position so it would be arround object
    return position;
}

Answer 3

我最后进行了两次Matrox旋转和一个矢量来用作Arcball旋转