Re: [Opensg-users] CAVE HUGE PROBLEMS

[antonio_lioy <ant...@li...>]

---------- Initial Header -----------

From      : ope...@li...
To          : "users" ope...@li...
Cc          : 
Date      : Fri, 25 Nov 2005 11:10:17 -0700
Subject : Re: [Opensg-users] CAVE HUGE PROBLEMS







> 
> 	Hi Antonio,
> 
> On Fri, 2005-11-25 at 13:13 +0100, antonio_lioy wrote:
> > Sorry for annoying once more. I'm sending pictures of my cave.
> > As you can see in one of them there's little distorsion , while in th=
e
> > other the red line appears to be broken.
> 
> What's the difference between the two pictures, i.e. what do you do to
> get one or the other?

The purpose of the two images is just to show that horizontal axis  looks=
 good, while the more the inclination of one axis with respect to the flo=
or the more the distorsion. The second image shows the first one after a =
bit inclination with  the navigator...
As you can see the more the inclination, the more the distorsion..
Can this mean something?? 

> 
> > I realize that probably I'm doing something wrong with the navigation=
,
> > cause I'm a bit confused with coordinate systems.
> > Our tracking system has a local coordinate with origin in the center
> > of our room and axis that are aligned to the CAVE walls.
> 
> OK.
> 
> > I used a perspective camera that is looking down Z axis position =3D>=

> > (0,0,10). This camera has four ProjectionCameraDecorator (2 for each
> > eye), and I'm passing the decorators the points of CAVE walls in
> > tracking coordinates.
> 
> The Camera doesn't really matter, only the beacon is used, the actual
> projection is defined by the Decorators.
> 
> > For navigation purposes I'm using a Navigator that acts on the beacon=

> > of our camera (the user Node of the decorator is initialized to
> > identity matrix).
> 
> OK.
> 
> >  What I don't understand at the moment is: what is the relation
> > between the coordinate system  of my tracking system  and the
> > coordinate systems that OpenSG uses to draw on the screens? I think I=

> > should think to project the coord system in my cave on the two walls,=

> > as if the projection plane were the wall of my cave... Uhm, there's
> > something wrong but I don't know what it is.
> 
> All that depends on where the head is. Unless the head is exactly in th=
e
> origin, you will never see the coordinate axes projected straight onto
> the walls.
> 

Uhm, OK. By the way when you say "origin", you mean that of the tracking =
system, don't you?

> Where do you put the matrix that you get from your tracker? You should
> have a Node (the User of the Decorator) with a Transform core under you=
r
> navigation beacon, which contains the Matrix you get from the tracker,
> plus some correction for the offset between tracker and ete position
> (see my last mail).
> 

We don't use the tracking system at the moment... (but we should use it s=
oon). The User of the Decorator is set to Identity and doesn't change. We=
 just use the navigator through navigation window to simulate movement of=
 the camera. The navigator works on a global beacon, which is the father =
of the Decorator User node.

> Hope it helps
> 
> 	Dirk
> 
> 

Thanks... But i really need more help. What are the coordinate systems in=
volved? The tracker's one, but what about OpenSG? where should I think th=
at OpenSG Axis are placed? This is not very clear...

Thanks a lot

> 
> 
> -------------------------------------------------------
> This SF.net email is sponsored by: Splunk Inc. Do you grep through log =
files
> for problems?  Stop!  Download the new AJAX search engine that makes
> searching your log files as easy as surfing the  web.  DOWNLOAD SPLUNK!=

> http://ads.osdn.com/?ad_id=3D7637&alloc_id=3D16865&op=3Dclick
> _______________________________________________
> Opensg-users mailing list
> Ope...@li...
> https://lists.sourceforge.net/lists/listinfo/opensg-users
>