POV-Ray : Newsgroups : povray.binaries.images : Sor / Lathe Discrepancy? (Corresp. to Post in General) Server Time
18 Nov 2024 16:19:33 EST (-0500)
  Sor / Lathe Discrepancy? (Corresp. to Post in General) (Message 1 to 2 of 2)  
From: Lieut Data
Subject: Sor / Lathe Discrepancy? (Corresp. to Post in General)
Date: 26 Mar 2002 15:43:42
Message: <3ca0dd7e@news.povray.org>
After reading through some of the source code for PovRay, I discovered that
(I think) Sor's and Lathe's use cubic splines to calculate their points. But
after rendering the following scene, where each lathe uses the same point
setup as each sor, I am confused.

What method does sor use to calculate splines? (Picture at Bottom)

 #declare myLathe = lathe {
   cubic_spline
   7,
   <0, -5>, //Control Point
   <.8, -.3>,
   <.2, 0>,
   <.3, .3>,
   <.5, .5>,
   <.2, .6>,
   <0, 5> //Control Point
   sturm
   pigment {color rgb<1, 0, 0>}
 }

 #declare mySor = sor {
   7,
   <0, -5>, //Control Point
   <.8, -.3>,
   <.2, 0>,
   <.3, .3>,
   <.5, .5>,
   <.2, .6>,
   <0, 5> //Control Point
   pigment {color rgb<1, 1, 1>}
   sturm
}

object {myLathe translate x*1}
object {mySor translate x*-1}

object {myLathe rotate x*-70 translate <1, 1.5, 3>}
object {mySor rotate x*-70 translate <-1, 1.5, 3>}


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Attachments:
Download 'sorelathe.png' (23 KB)

Preview of image 'sorelathe.png'
sorelathe.png


 

From: Shay
Subject: Re: Sor / Lathe Discrepancy? (Corresp. to Post in General)
Date: 26 Mar 2002 16:01:37
Message: <3ca0e1b1@news.povray.org>
Sor cannot bend back on itself. That is the reason for discrepancy.

 -Shay
Lieut_Data <lIe### [at] yahOOcom> wrote in message
news:3ca0dd7e@news.povray.org...


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