min3D框架。 物体旋转与运动

Question

I am trying to code a cessna flying around the world using the accelerometer with the min3D framework for android but the rotation is a bit weird.

I'm using this to apply the accelerometer rotation to the object:

cessna.rotation().x = rotX;
cessna.rotation().z = rotZ;

This works fine. I haven't figured out yet how to move in the direction of rotation (I think I have to use trigonometry).

I rotated the object with

cessna.rotation().y++;

just to test what will happen. At 180° the rotation around the x axis is mirrored. So the nose of the plane turns down instead of up. I think I rotate the Objects around the world axis and not around the local axis from the object. How can I do this? I didn't find any documentation about the min3D framework in the internet :/ .

Thank you if you can help me. (sorry for the bad English)

Answer 1

If you want to rotate around object local axis. Do this

(in pseudo code - you'll need to find similar functions in min3d) Translate(object.pos.x,object.pos.y,object.pos.z); object.rotation().x+=radians(45);// or whatever Translate(object.pos.x,object.pos.y,object.pos.z); object.rotation().x+=radians(45);// or whatever

if that doesn't work, try wrapping the above two lines in

pushMatrix()
...
popMatrix()

Or similar functions in min 3d to save and then restore the current camera rotation translation matrix.

Have you considered, Processing, which also comes with an Android 'output'?