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Where is the camera defined?I have the same question also....and probably I
can help a lil bit!!!
I want to change manually the virtual camera.....actually I need to change
the field of view angle in order to overlay manually the virtual object with
a real one.
As I could know, the camera parameters are loaded from the camera
calibration file. The parameters are loaded into a variable called i.e
cparam. Within the init() procedure, there is a called to the function
'argInit(some values here)' , in that function, the variable cparam is
converted to 'gl_cpara' , which is used for ARToolkit every time you want to
set the projection model before drawing the 3D object==> thus, using
'argDraw3Dcamera(0,0)'.
I could figure out, if I'm not wrong, that 'gl_cpara' is the vector version
of some kind of perspective matrix. I couldn't get to know how can I relate
the field of view angle with the values in that vector or where in the
process from 'cparam' to gl_cpara' is possible to modify it.
Hirokazu Kato gave me some time ago a link to a web page where there is
information about transformation matrixs and prespective matrixs....I could
find some similarities between the frustum matrix in that link and the way
the gl_cparam is obtained.....
http://fly.cc.fer.hr/~unreal/theredbook/appendixg.html
I hope that with this information you can get some clue, and also that you
can help me....
any other one that knows about it, will be 'welcome'....hehehe :)
waiting for answers, please!!!
Begoņa.-
-----Mensaje original-----
De: owner-artoolkit@h ..................
[mailto:owner-artoolkit@h ..................]En nombre de Oppermann, Andreas
(K-DOE-3)
Enviado el: martes, 15 de junio de 2004 9:58
Para: 'artoolkit@h ..................'
Asunto: Where is the camera defined?
Hi,
I have a question about the viewing and projection matrices in the
ArToolkit.
I worked my way through the example programs and found out that the
toolkit defines a projection matrix in form of a 4x3 matrix. That matrix
will be extended to a 4x4 matrix and then loaded onto the OpenGL projection
stack. My question is basically how and where in the source code this matrix
gets defined. Does it contain information about the orientation (position,
up vector and dir vector), the field-of-view angle and the aspect ratio?
My problem is, that I try to combine the toolkit with a vrml viewer and
that I am very restriced in setting the viewers camera parameters. Therefore
I would be interested in retrieving the camera parameters seperately instead
of a matrix. Would it be possible to access the required data?
Thanks
Andreas
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<HTML><HEAD><TITLE>Where is the camera defined?</TITLE>
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<DIV><SPAN class=3D671422519-15062004><FONT face=3DArial color=3D#0000ff =
size=3D2>I have=20
the same question also....and probably I can help a lil=20
bit!!!</FONT></SPAN></DIV>
<DIV><SPAN class=3D671422519-15062004><FONT face=3DArial color=3D#0000ff =
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D671422519-15062004><FONT face=3DArial color=3D#0000ff =
size=3D2>I want=20
to change manually the virtual camera.....actually I need to change the =
field of=20
view angle in order to overlay manually the virtual object with a real=20
one.</FONT></SPAN></DIV>
<DIV><SPAN class=3D671422519-15062004><FONT face=3DArial color=3D#0000ff =
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D671422519-15062004><FONT face=3DArial color=3D#0000ff =
size=3D2><FONT=20
color=3D#000000>As I could know, the camera parameters are loaded from =
the camera=20
calibration file. The parameters are loaded into a variable called i.e=20
cparam. Within the init() procedure, there is a called to the =
function 'argInit</FONT>(<FONT color=3D#ff0000>some values =
here</FONT>)<FONT=20
color=3D#000000>' , in that function, the variable cparam is =
converted to=20
'gl_cpara' , which is used for ARToolkit every time you want to set the=20
projection model before drawing the 3D object=3D=3D> thus, using =
'argDraw3Dcamera(0,0)'.</FONT></FONT></SPAN></DIV>
<DIV><SPAN class=3D671422519-15062004><FONT face=3DArial=20
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D671422519-15062004><FONT face=3DArial size=3D2>I =
could figure out,=20
if I'm not wrong, that 'gl_cpara' is the vector version of some kind of=20
perspective matrix. I couldn't get to know how can I relate the field of =
view=20
angle with the values in that vector or where in the process from =
'cparam' to=20
gl_cpara' is possible to modify it. </FONT></SPAN></DIV>
<DIV><SPAN class=3D671422519-15062004><FONT face=3DArial color=3D#0000ff =
size=3D2><FONT=20
color=3D#000000>Hirokazu Kato gave me some time ago a link to a web page =
where=20
there is information about transformation matrixs and prespective =
matrixs....I=20
could find some similarities between the frustum matrix in that link and =
the way=20
the gl_cparam is</FONT> <FONT color=3D#000000>obtained.....</FONT> <A=20
href=3D"http://fly.cc.fer.hr/~unreal/theredbook/appendixg.html">http://fl=
y.cc.fer.hr/~unreal/theredbook/appendixg.html</A>=20
<A></A></FONT></SPAN></DIV>
<DIV><SPAN class=3D671422519-15062004><FONT face=3DArial color=3D#0000ff =
size=3D2></FONT></SPAN><SPAN class=3D671422519-15062004><FONT =
face=3DArial=20
color=3D#0000ff size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D671422519-15062004><FONT face=3DArial size=3D2>I hope =
that=20
with this information you can get some clue, and also that you=20
can help me....</FONT></SPAN></DIV>
<DIV><SPAN class=3D671422519-15062004><FONT face=3DArial=20
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D671422519-15062004><FONT face=3DArial size=3D2>any =
other one that=20
knows about it, will be 'welcome'....hehehe :)</FONT></SPAN></DIV>
<DIV><SPAN class=3D671422519-15062004><FONT face=3DArial=20
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D671422519-15062004><FONT face=3DArial =
size=3D2>waiting for answers,=20
please!!!</FONT></SPAN></DIV>
<DIV><SPAN class=3D671422519-15062004><FONT face=3DArial=20
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D671422519-15062004><FONT face=3DArial=20
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D671422519-15062004><FONT face=3DArial=20
size=3D2>Bego=F1a.-</FONT></SPAN></DIV>
<DIV><SPAN class=3D671422519-15062004><FONT face=3DArial color=3D#0000ff =
size=3D2><STRONG></STRONG></FONT></SPAN> </DIV>
<DIV><SPAN class=3D671422519-15062004><FONT face=3DArial color=3D#0000ff =
size=3D2><STRONG> </STRONG></FONT></SPAN></DIV>
<DIV><SPAN class=3D671422519-15062004><FONT face=3DArial color=3D#0000ff =
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D671422519-15062004><FONT face=3DArial color=3D#0000ff =
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D671422519-15062004><FONT face=3DArial color=3D#0000ff =
size=3D2></FONT></SPAN> </DIV>
<DIV><SPAN class=3D671422519-15062004></SPAN><FONT face=3DTahoma =
size=3D2>-----Mensaje=20
original-----<BR><B>De:</B> owner-artoolkit@h ..................=20
[mailto:owner-artoolkit@h ..................]<B>En nombre de =
</B>Oppermann,=20
Andreas (K-DOE-3)<BR><B>Enviado el:</B> martes, 15 de junio de 2004=20
9:58<BR><B>Para:</B> 'artoolkit@h ..................'<BR><B>Asunto:</B> =
Where is=20
the camera defined?<BR><BR></DIV></FONT>
<BLOCKQUOTE dir=3Dltr style=3D"MARGIN-RIGHT: 0px">
<P><FONT face=3DArial size=3D2>Hi,</FONT> <BR><FONT face=3DArial =
size=3D2>I have a=20
question about the viewing and projection matrices in the =
ArToolkit.</FONT>=20
</P>
<P><FONT face=3DArial size=3D2>I worked my way through the example =
programs and=20
found out that the toolkit defines a projection matrix in form of a =
4x3=20
matrix. That matrix will be extended to a 4x4 matrix and then loaded =
onto the=20
OpenGL projection stack. My question is basically how and where in the =
source=20
code this matrix gets defined. Does it contain information about the=20
orientation (position, up vector and dir vector), the field-of-view =
angle and=20
the aspect ratio?</FONT></P>
<P><FONT face=3DArial size=3D2>My problem is, that I try to combine =
the toolkit=20
with a vrml viewer and that I am very restriced in setting the viewers =
camera=20
parameters. Therefore I would be interested in retrieving the camera=20
parameters seperately instead of a matrix. Would it be possible to =
access the=20
required data?</FONT></P><BR>
<P><FONT face=3DArial size=3D2>Thanks</FONT> <BR><FONT face=3DArial=20
size=3D2>Andreas</FONT> </P></BLOCKQUOTE></BODY></HTML>
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