I see nothing my Image is only black ?
This can happen if the video driver doesn't work properly and no image
is returned. Try to
run your camera with other video viewer to check if the video driver
are all rights. You can use
amcap.exe on Windows, XXX on Linux or XXX on MacOS.
I see nothing my Image is blue?
This can happen with video TV card. Generally you have the bad channel
input used with ARToolKit. You can
change it manually on vconf or with the intermediate of GUI program
(like amcap->Video Filter..).
My image is upside down !!
You need to add the 'flipV' parameter to vconf.
Which format my camera used ?
At present in the toolkit (v2.70.1) the video format used is determined
at compile-time, by options in config.h. Take a look and see what
format is being used.
I'm trying to compile example under Windows
platform the compiler shows the error message : "streams.h" is not
found ?
I have the fatal error C1083: Cannot open
include file: 'GL/glext.h': No such file or directory ?
the missing glext.h arises because lots of people having OpenGL headers
for OpenGL 1.2, and glext.h was not separated out of gl.h until 1.3.
You can find it: http://oss.sgi.com/projects/ogl-sample/ABI/glext.h
I get the error msg when I start the
simpleTest program:
"this device can not be supported by libARvideo.
(vm.frames < 2)" ?
ARtoolkit test if your camera can do double buffering (vm.frames) : if
not the camera is rejected it (the message error). try to reinstall the
latest version of your driver.
On Windows, I have identifiers such as
DWORD_PTR, LONG_PTR undefined ?
The kind of errors you are seeing are typical if you are trying to use
DirectX 9.0c with Visual Studio 6, as DirectX 9.0c does not support
Visual Studio 6.
How I get the distance between two Markers ?
The last column of the patt_trans matrix is the relative translation
between marker and camera. For the second marker, the camera is the
same, so you can use the inverse of the second patt_trans matrix to
multiply the first one, then you will get the relative translation
between these two markers.
inv=inverse(Matrix1);
Matrix3=inv*Matrix2;
Matrix1 is the transformation of marker 1
Matrix2 is the transformation of marker 2
Matrix3 is the relation of marker 1 and 2. If you check the
translation column of matrix 3, you can see the distance between
marker 1 and 2.
Check the example relation distribute with ARToolKit.
On Linux, I have this error:arVideoOpen:
width or height oversize
The Video4Linux driver in ARToolKit is coded to request a particular
sized video frame and if your camera does not support that resolution
then it will fail with that error message.
If you supply -width and -height arguments inside simpleTest (by vconf
variable) then it will prevent this error message.
I am using a "something 1394" webcam which
supports 30 frames per second at a
resolution of 640x480. However the frame rate is always less than 15
fps.
One thing to do is make sure you have the drivers installed. If it saws
"Generic 1394 Camera" or something like that in hardware manager,
then you are using the default windows drivers, which can only do 15
fps with these sorts of cameras.