object 3D registration in ARToolki

[deduu]

hai ...

I'm learning building AR with ARToolkit library. I conducted some observation from the sourcecode provided by this library, let's say simpletest. and then in draw function I changed the translation value of z axis from 25.0 to 0.0 (original: glTranslatef(0.0, 0.0, 25.0) to glTranslatef(0.0, 0.0, 0.0)). when I did this, I found out that the cube I rendered as if "running" as I rotated my marker along x axis. Meanwhile using the original, it does not "running" when I rotated the marker. Can anyone explain why it was that?

glTranslatef(0.0, 0.0, 0.0)) yields

http://i48.tinypic.com/2803f4.jpg

original: glTranslatef(0.0, 0.0, 25.0) yields

http://i50.tinypic.com/2hi8j1e.jpg

thanks

[Brian Leung]

hi,

seems like the cube pose is not right above the marker in your first picture. I forgot why we need to offset the z-axis by 25.0 and I guess it's something
related to how the cube is drawn and the assumed size of marker (50mm x 50mm..half will be 25.0).

Brian

[deduu]

hai, thanks Brian .
by the way do you know how artoolkit determine the marker position in world coordinate and how to get the transformation value after getting the marker position ?

Dedy