fisheye projection camera? So for a upward looking fisheye at height z = 0 -
where is the image plane and what is the handling of scene objects which are in
between the camera location and the image plane?

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Le 14/03/2011 08:56, JohnnyCatch a écrit :
> Does anybody has figured out the location of the (curved) image plane of a 180°
> fisheye projection camera? So for a upward looking fisheye at height z = 0 -
> where is the image plane and what is the handling of scene objects which are in
> between the camera location and the image plane?

The image plane is like the cake of portal.

So far, for most camera's types (orthographic is an exception, as well
as cylinders and maybe the new mesh camera too), the origin of each ray
is the camera's location.

For 3.6 sources, have a look in render.cpp at create_ray function.
(the default is to assign FCL (Frame.Camera->Location) to the
Ray->Initial at the beginning of the function. Unless overridden by the
camera's code, it remains as set. Fisheye does not override it.)

Have a nice day.
-- 
Software is like dirt - it costs time and money to change it and move it
around.

Just because you can't see it, it doesn't weigh anything,
and you can't drill a hole in it and stick a rivet into it doesn't mean
it's free.

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Le_Forgeron <lef### [at] freefr> wrote:
> Le 14/03/2011 08:56, JohnnyCatch a écrit :
> > Does anybody has figured out the location of the (curved) image plane of a 180°
> > fisheye projection camera? So for a upward looking fisheye at height z = 0 -
> > where is the image plane and what is the handling of scene objects which are in
> > between the camera location and the image plane?
>
> The image plane is like the cake of portal.
>
> So far, for most camera's types (orthographic is an exception, as well
> as cylinders and maybe the new mesh camera too), the origin of each ray
> is the camera's location.
>
> For 3.6 sources, have a look in render.cpp at create_ray function.
> (the default is to assign FCL (Frame.Camera->Location) to the
> Ray->Initial at the beginning of the function. Unless overridden by the
> camera's code, it remains as set. Fisheye does not override it.)
>
> Have a nice day.
> --
> Software is like dirt - it costs time and money to change it and move it
> around.
>
> Just because you can't see it, it doesn't weigh anything,
> and you can't drill a hole in it and stick a rivet into it doesn't mean
> it's free.

Thanks a lot but what you mean with "cake of portal"?
Ciao

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Le 14/03/2011 10:41, JohnnyCatch a écrit :
> Le_Forgeron <lef### [at] freefr> wrote:
>> Le 14/03/2011 08:56, JohnnyCatch a écrit :
>>> Does anybody has figured out the location of the (curved) image plane of a 180°
>>> fisheye projection camera? So for a upward looking fisheye at height z = 0 -
>>> where is the image plane and what is the handling of scene objects which are in
>>> between the camera location and the image plane?
>>
>> The image plane is like the cake of portal.

> Thanks a lot but what you mean with "cake of portal"?
> Ciao

It does not exist.
The cake is a lie. (it's a classical quote from the game Portal)

So is the "image plane" for the camera in povray: it does not really
exist. It's an analogy taken from the photographic domain, in which the
image plane is the actual plane on which the film is set. Anything in
front of the image plane will appear on the film, anything behind just
won't appear.

Usually, the film is beyond the diaphragm, at the focal plane. (and the
image is inversed: the top of the view is at the bottom of the film,
same for left & right...)

For povray's main set of cameras, the film is just a point at the camera
location.

-- 
Software is like dirt - it costs time and money to change it and move it
around.

Just because you can't see it, it doesn't weigh anything,
and you can't drill a hole in it and stick a rivet into it doesn't mean
it's free.

Post a reply to this message