opengl相机围绕对象旋转

Question

I'm fighting with the code, to make it rotate camera around the object. The code that I'm using is:

eyeX = (float) (obj.x + 500*Math.cos(Math.toRadians(angle))*Math.sin(Math.toRadians(angle))); eyeY = (float) (obj.y + 500*Math.sin(Math.toRadians(angle))*Math.sin(Math.toRadians(angle))); eyeZ = (float) (obj.z + 500*Math.cos(Math.toRadians(angle))); Matrix.setLookAtM(mViewMatrix, 0, eyeX, eyeY, eyeZ, obj.x, obj.y, obj.z, 0, 1, 0);

Where obj is the model I want to rotate the camera around, and angle is incremented by 1 with every draw. Can somebody shed a light to this problem, what I'm doing wrong?

Answer 1

What exact camera motion are you trying to achieve? If you want to turn around obj on the XZ plane while remaining at a constant height, you should do:

eyeX = (float)(obj.x + 500*Math.cos(Math.toRadians(angle));

eyeY = (float)(y0); //constant height

eyeZ = (float)(obj.z + 500*Math.sin(Math.toRadians(angle));

Also, if y0 != 0, then (0, 1, 0) is not a proper "up" vector and will distort you view.