This seems to be the appropriate group

How would it be possible to create a mirage in any current or old
version of POV-Ray (I imagine that the interior of an object could
modify the direction a ray is traced backwards ??)

Post a reply to this message

On Thu, 16 Mar 2000 13:58:57 +0800, Pabs <pab### [at] hotmailcom> wrote:

>This seems to be the appropriate group
>
>How would it be possible to create a mirage in any current or old
>version of POV-Ray (I imagine that the interior of an object could
>modify the direction a ray is traced backwards ??)

Refraction is surely one way to do it. Keep in mind that most if not
all types of mirages are caused by the variable ior of hot vs. cold
air, and in POV there's no variable ior. One can however use a distant
transparent plane with refraction and a varying normal to achieve if
not a mirage then at least a heat wave effect. Another idea is to use
the camera ray perturbation feature in POV. One way or the other
you'll have to fake it.


Peter Popov
pet### [at] usanet
ICQ: 15002700

Post a reply to this message

"Peter Popov" <pet### [at] usanet> wrote in message
news:n5HQOC6KhugVTNYVWcRouktn4iBJ@4ax.com...
| On Thu, 16 Mar 2000 13:58:57 +0800, Pabs <pab### [at] hotmailcom> wrote:
|
| >How would it be possible to create a mirage in any current or old
| >version of POV-Ray (I imagine that the interior of an object could
| >modify the direction a ray is traced backwards ??)
|
| Refraction is surely one way to do it. Keep in mind that most if not
| all types of mirages are caused by the variable ior of hot vs. cold
| air, and in POV there's no variable ior.

A possibility might be to use a 'texture_map' in POV-Ray 3.0*, but not in 3.1
(using the #version directive doesn't work).
Before refraction was moved into the 'interior' statement it was possible to use
ior in finishes and thus also in texture maps to 'average' or otherwise pattern
the refractions together.  This would make for a variable refraction.

Bob

Post a reply to this message

Peter Popov wrote in message ...
>On Thu, 16 Mar 2000 13:58:57 +0800, Pabs <pab### [at] hotmailcom> wrote:
>>How would it be possible to create a mirage in any current or old
>>version of POV-Ray (I imagine that the interior of an object could
>>modify the direction a ray is traced backwards ??)
>
>Refraction is surely one way to do it. Keep in mind that most if not
>all types of mirages are caused by the variable ior of hot vs. cold
>air, and in POV there's no variable ior

You can fake a continuously variable IOR by stacking a number of very thin
boxes with the desired IORs.  This will approximate a variable IOR, but will
take an extremely long time to render.

Mark

Post a reply to this message