POV-Ray : Newsgroups : povray.advanced-users : Re: INFO: Inverse Server Time
14 Jul 2024 06:40:05 EDT (-0400)
  Re: INFO: Inverse (Message 1 to 3 of 3)  
From: Bob Hughes
Subject: Re: INFO: Inverse
Date: 27 Apr 1999 07:30:25
Message: <3725918C.708FD159@aol.com>
No, 'inverse' is specifically for object surface distinctions. At least
this is my call on it. It will only act to change inside/outside.
Transformations (scale, rotate, translate, etc.) are independant of this
keyword.
To switch the transformation order you will no doubt need a set of
switches or some such thing to parse which ones you want ahead of the
other, as in:

 #declare Sw = 1 //set switch

 sphere {0,1
 #switch (Sw)
 #case (1)
  scale <1,1,1>
  rotate <10,10,10>
  translate <20,20,20>
 #break
 #case (2)
  rotate <10,10,10>
  scale <1,1,1>
  translate <20,20,20>
 #break
 #case (3)
  translate <20,20,20>
  scale <1,1,1>
  rotate <10,10,10>
 #break
 #end
 }



Hassoun wrote:
> 
> Hi
> can i use "inverse" to reverse the order (or the sequence) in which
> objects are modified (translated, rotated, scaled)? any info of how to
> do this operation?
> 
> thanks in advance
> Hassoun

-- 
 omniVERSE: beyond the universe
  http://members.aol.com/inversez/homepage.htm
 mailto:inv### [at] aolcom?Subject=PoV-News


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From: Josh English
Subject: Re: INFO: Inverse
Date: 27 Apr 1999 12:13:36
Message: <3725D3EB.77FF5EE3@spiritone.com>
Inverse only applies to unions, differences, etc...

You want to apply a warp statement to the object.
from the docs...

However, by specifying our turbulence inside warp statement you tell
POV-Ray that the order in which turbulence, transformations and other
warps are applied is significant. Here's an example of a turbulence warp.

  warp { turbulence <0,1,1> octaves 3 lambda 1.5 omega 0.3 }

The significance is that this

 pigment {
   wood
   translate <1,2,3> rotate x*45 scale 2
   warp { turbulence <0,1,1> octaves 3 lambda 1.5 omega 0.3 }
 }

produces different results than this...

 pigment {
   wood
   warp { turbulence <0,1,1> octaves 3 lambda 1.5 omega 0.3 }
   translate <1,2,3> rotate x*45 scale 2
 }

You may specify turbulence without using a warp statement. However you
cannot control the order in which they are evaluated unless you put them
in a warp


Josh English
eng### [at] spiritonecom
Hassoun wrote:

> Hi
> can i use "inverse" to reverse the order (or the sequence) in which
> objects are modified (translated, rotated, scaled)? any info of how to
> do this operation?
>
> thanks in advance
> Hassoun


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From: Ron Parker
Subject: Re: INFO: Inverse
Date: 27 Apr 1999 13:33:03
Message: <3725e6bf.0@news.povray.org>
On Tue, 27 Apr 1999 08:12:44 -0700, Josh English wrote:
>Inverse only applies to unions, differences, etc...

Not true.  It applies to all objects with insides.  It just doesn't
usually matter except in CSG (and in bounded_by and clipped_by) and
perhaps with media.


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