Mike,

By reading the code you linked in your answer I am puzzle, and I don't really see how to integrate that concept into my own code without shamelessly copying some of your methods directly into my code and and adapt it :(

So, have you any book recommendation that discuss such matter for someone that have not played with stuff like matrices for 15 years and never heard of quaternions until learning OpenGL?

There is so much books on math for computer graphics, game development, physics, ai, ... that I don't know which one to choose.

I should have maybe precised that self.thrust and self.tick are float, so I don't see how that will interact with self.orientation that is a quaternion if I have understand correctly.

Thanks,

Roland.

Le 08/03/10 22:34, Roland Everaert a écrit :
Thanks for the example and the explanation, I will have a look at it asap.

Roland.

Le 08/03/10 17:01, Mike C. Fletcher a écrit :
On 10-08-02 04:57 PM, Roland Everaert wrote:
```Hi,

I am currently writing a third person view space shooter where the
player can freely fly in the "map". I want to define an arcade flying
model like in most space shooter or spaceship simulation, but I face the
problem of specifying the transformation right.

For the moment, my scene contains the player space ship pointing toward
the negative z axis, with the camera a little bit behind it. In front of
the ship there are 2 objects. When I apply some thrust to the player
spaceship it goes forward, but if I turn the ship, it is not changing
direction, while the ship and the camera are turning.

My questions are the following:

1. Given the code below, why have I to call the method
self.__chasingView() after rendering the player's ship?

2. How to change the direction of the ship? Am I missing some glRotate()
functions somewhere in the code or should I change the code of method
setNewPosition() in such a way that the position of the ship is computed
on all 3 axis?
```
The problem you are facing is that you want to make the motion of the ship (x,y,z) modify by currentrotation * motionvector.  You *could* do that with an ever-increasing set of glRotate/glTranslate calls (you'd need one for every change in direction), but what you really want to do is to track your position in "world" space and change that position by currentrotationmatrix * motionvector.

I normally do that with a wrapped Quaternion class in OpenGLContext.  See OpenGLContext/move/viewplatform.py for the code that wraps it (particularly the relativePosition() method, on which all of the various forward/sideways/up/down movements are built.

http://bazaar.launchpad.net/~mcfletch/openglcontext/trunk/annotate/head:/OpenGLContext/move/viewplatform.py
```     def setNewPosition(self):
self.addToPosition(z=-(self.thrust * self.tick))
```
that should be something like self.addToPosition( self.thrust * self.tick * self.orientation )

HTH,
Mike
```--
________________________________________________
Mike C. Fletcher
Designer, VR Plumber, Coder
http://www.vrplumber.com
http://blog.vrplumber.com
```
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