I'm not sure if I should post it here, but here is my problem.

I'm a PhD student working on a position tracking software.
This software just use a single camera and some paper markers to work 
out the camera position.
I've done two series of tests, one is using simulation, feed the image 
that is generated by povray, the other is doing in the real world 
environment with a real camera.
The result is, on both the simulation and the real world environment, 
the x and y position is quite accurate.
But the resulting z position (the distance of the camera from the 
marker) is really inaccurate in the simulation. While the accuracy on 
this is very accurate on the real world environment.

I wonder if this is the camera setting (in povray) problem? or the image 
resolution problem? (but I've rendered the image with the same dimension 
as the image grab by the camera.)

Does anyone has some clue on it?

Colin

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<use### [at] domaininvalid> wrote in message news:41c300a4$1@news.povray.org...

> I wonder if this is the camera setting (in povray) problem? or the image
> resolution problem? (but I've rendered the image with the same dimension
> as the image grab by the camera.)
>
> Does anyone has some clue on it?
>

Very hard to say w/o more info. - however I would hazard a guess that you
may have distorted your image by only changing the output dimensions of the
image, and that you need to make suitable modifications to the field-of-view
of the image as well.

Can you post your camera settings, as well as your output settings?

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I was just using the povray default camera, with the view (horizontal)
angle modified to the same as the actual camera, that's about 67 degree.

And my output dimension is with these options:
+W384 +H288



Tom Melly wrote:
> <use### [at] domaininvalid> wrote in message news:41c300a4$1@news.povray.org...
> 
> 
>>I wonder if this is the camera setting (in povray) problem? or the image
>>resolution problem? (but I've rendered the image with the same dimension
>>as the image grab by the camera.)
>>
>>Does anyone has some clue on it?
>>
> 
> 
> Very hard to say w/o more info. - however I would hazard a guess that you
> may have distorted your image by only changing the output dimensions of the
> image, and that you need to make suitable modifications to the field-of-view
> of the image as well.
> 
> Can you post your camera settings, as well as your output settings?
> 
>

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use### [at] domaininvalid wrote:
> Does anyone has some clue on it?

   Posting both images on p.b.i. would help greatly to understand your 
problem...

--
Jaime

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Wasn't it  who wrote:
>I was just using the povray default camera, with the view (horizontal)
>angle modified to the same as the actual camera, that's about 67 degree.

Make sure that you're measuring exactly the same thing when you're
comparing the real camera angle to what POV uses in its camera angle
keyword.

In POV
   tan(angle/2) = right/(2*distance)

-- 
Mike Williams
Gentleman of Leisure

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