Visually correct rotation with OpenGl and touch screen capabilities

问题

I have been trying to do Cube of Rubik for android. I have one question about rotations. I want to rotate a figure visually correct. It means if user touch screen and after move his finger to right a figure rotate to right from side of observation point. But when I make some rotations the figure start move in not correct direction. I understand that it depends on that axis are change their situation. But I tried to use inverse model matrix to get necessary coordinates, but I haven't already result. Could anybody give me example or link of visually correct rotation of 3D figure with help of mouse or touch screen?

   //get vector 3D of touch
   Vector3f touchVector = getRubikSystemCoordinates(mTouchX,mTouchY,square.rubikRotationMatrix);
   //Get vector 3D of move     
   Vector3f moveVector = getRubikSystemCoordinates(mMoveX,mMoveY,square.rubikRotationMatrix);
        //get direction of motion
        float direction = touchVector.substractFrom(moveVector); 
        //get axis for rotation
        Vector3f axis = touchVector.vectorProductTo(moveVector);
        //normalize axis
        axis.normalize();
        //get angle of rotation
        float angle = direction.length;
        //make identity Quad
        Quaternion quad = new Quaternion();
        //make rotation quad
        quad.makeRotationKvaternion(angle,axis);
        //from quad recieve matrix
        Matrix4f matrix = quad.toMatrix();
        //multiply to current modelview matrix
        gl.glMultMatrixf(matrix.returnArray(),0);
        //save rotation matrix
        square.rotationMatrix = square.rotationMatrix.multiply(matrix);
        //save modelView matrix
        square.saveModelView(square.initMatrix.returnArray()); 


      // touch coords to current modelView coords
      private Vector3f getRubikSystemCoordinates(float x, float y, Matrix4f matrix){
       // touch coords to normal coords of screen 
       Vector2f normalCoords = (new Vector2f(x,y)).toNormalScreenCoordinates(Settings.viewPort[2],Settings.viewPort[3]);
        // to sphere coords in 3D
        Vector3f sphereVector = new Vector3f(normalCoords.x,normalCoords.y, FloatMath.sqrt(2-normalCoords.x*normalCoords.x-normalCoords.y*normalCoords.y));
        //Get inverse matrix from ModelView Matrix
        Matrix4f m = matrix.inverseMatrix();
        //Get vector for current modelView 3D coords
        Vector3f vector = m.multiplyToVector(vector);
        // make normalize vector
        vector.normalize();
        return vector;
        }

回答1:

What you're looking for is named arcball rotation. You'll find plenty of resources in java around the internet on this.

回答2:

You are probably storing your rotation as three angles. Use matrix instead. Create a separate transformation matrix just for this rotation. Every time user rotates the object apply the rotation to this matrix. This way the movement will always be relative to current orientation.

来源：https://stackoverflow.com/questions/11207805/visually-correct-rotation-with-opengl-and-touch-screen-capabilities