Hi
  I'm new to Povray (although not to graphics in general) and am
having some problems.
  I've got a nice mesh created and am now trying to view it from a
variety of different angles.

  There is a 'ground' set up in the z=0 plane, and all the objects
have positive z.

  I used a camera at
 location <0, -264, 5 >
 look_at <0,10,0>

and everything was the right way up.

  The reverse angle shot
  location <0, 264, 5 >
  look_at <0, -10, 0 >

appears upside-down, and anything that I do with the up attribute doesn't
seem to make a difference

any hints?


Thanks

Colin Plummer *frustrated*

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Colin Plummer wrote:
> 
> Hi
>   I'm new to Povray (although not to graphics in general) and am
> having some problems.
>   I've got a nice mesh created and am now trying to view it from a
> variety of different angles.
> 
>   There is a 'ground' set up in the z=0 plane, and all the objects
> have positive z.
> 
>   I used a camera at
>  location <0, -264, 5 >
>  look_at <0,10,0>
> 
> and everything was the right way up.
> 
>   The reverse angle shot
>   location <0, 264, 5 >
>   look_at <0, -10, 0 >
> 
> appears upside-down, and anything that I do with the up attribute doesn't
> seem to make a difference
> 
> any hints?
> 
> Thanks
> 
> Colin Plummer *frustrated*


Pov uses a default system where +y = up. You need to redifine
your camera to account for this. A typical +z = up camera statement
might looks like this:

camera {
location  <  0,  -5, 0.1>
direction <0.0, 0.0, 1.0>
sky       <0.0, 0.0, 1.0>  // Use right handed-system!
up        <0.0, 0.0, 1.0>  // Where Z is up
right     <4/3, 0.0, 0.0>
look_at   <0.0, 0.0, 0.0>}

So you can see by changing your sky and up vectors you change
the handeness system used as default by the program.

This is covered in the doc's and more information on this subject
may be found at:

http://www.students.tut.fi/~warp/povVFAQ.html


-- 
Ken Tyler

mailto://tylereng@pacbell.net

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