Yes I know that I currently accumulate error, but when I did it I was
thinking about a zero-error so it wasn't a problem...
The NodeTrackerManipulator does it, yes, but I'm working on a manipulator
still existing in the project, and make a whole new manipulator looks a lot
of work and I don't have enough time to do it...
Maybe in the future...
Thanks for the help :-)
Regards,
Vincent.
2008/3/27, Robert Osfield <[EMAIL PROTECTED]>:
>
> Hi Vincent,
>
> You approach is iterative so the errors will accumulate, so it's based
> to avoid this and go fetch the world matrices from the node your
> tracking each frame. The osgGA::NodeTrackerManipulator does this.
>
> Robert.
>
> On Thu, Mar 27, 2008 at 8:57 AM, Vincent Bourdier
>
> <[EMAIL PROTECTED]> wrote:
> > Hi Robert,
> >
> > For the moment I use a relative calculation (I compute on each frame
> > depending on the last frame's position).
> > I suppose that computing in absolute mode could be better... but I would
> be
> > more difficult to implement.
> >
> > Thanks Robert, I'll will try this if I have some time...
> >
> > One more question : If there any conversion between Quat and Matrix, or
> Quat
> > and Vector, or Vector and Matrix which can not be precise ? I mean some
> > conversion function to avoid for example in the goal of beeing always
> > precise ?
> >
> > Regards,
> > Vincent
> >
> > 2008/3/27, Robert Osfield <[EMAIL PROTECTED]>:
> >
> > > Hi Vincet,
> > >
> > > Even with doubles there are still precisions issue, just much smaller
> > > than with floats. If you are using a iterative calculation then if
> > > you aren't care the errors could accumulate until their become
> > > visable. The best thing to do is to avoid an iterative calculation
> > > and calculate the new camera position based on the position of the
> > > node in the scene on each frame.
> > >
> > > Robert.
> > >
> > >
> > > On Thu, Mar 27, 2008 at 8:38 AM, Vincent Bourdier
> > > <[EMAIL PROTECTED]> wrote:
> > > > Hi all,
> > > >
> > > > I'm currently making a new Manipulator inherited from
> MatrixManipulator.
> > > >
> > > > The specificity is : On the call of a function, the manipulator
> (camera)
> > > > have to follow a node which is moving. I mean that the camera have
> to be
> > > > exactly immobile relative to the moving node.
> > > > For that i've used Matrix, Vec3 and Quat.
> > > >
> > > > All looks great, but after 10 minutes of running, I can see that a
> > little
> > > > moving difference between the node and the camera... if the node
> rotate
> > > > about 2 or 3 axis, the difference is more important...
> > > >
> > > > Using Vec3d, Quat and Matrixd, is there any reason for this lack of
> > > > precision ? Or is it my method which is not good... ?
> > > >
> > > > Thanks.
> > > >
> > > > Regards,
> > > > Vincent.
> > > >
> > >
> > > > _______________________________________________
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> > > >
> >
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> > > >
> > > >
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