POV-Ray : Newsgroups : povray.advanced-users : Q: smooth union of bezier patches Server Time
30 Jul 2024 18:20:07 EDT (-0400)
  Q: smooth union of bezier patches (Message 11 to 13 of 13)  
<<< Previous 10 Messages Goto Initial 10 Messages
From: Phil Clute
Subject: Re: Q: smooth union of bezier patches
Date: 29 Apr 1999 02:56:30
Message: <3727F5F5.19315C81@tiac.net>
Jerry Anning wrote:
If you want to see some examples of h spline techniques, check out the
Dragon Wing at:
http://www.cs.ubc.ca/nest/imager/contributions/forsey/dragon/top.html

This link has some great stuff. The dissapointment was that I
was looking around to see if a program was available but I didn't
see one there <boo, hiss>. 
The animations function well, that's definitely the idea I had in mind
as an ultimate goal(somewhere waaay down the road).

thanks
-- 
...coffee?...yes please! extra sugar,extra cream...Thank you.


Post a reply to this message

From: Marc Schimmler
Subject: Re: Q: smooth union of bezier patches
Date: 29 Apr 1999 05:51:52
Message: <37281DA7.115C24F0@ica.uni-stuttgart.de>
ingo wrote:
> 
> While exploring the bezier patches, I can not find a way to attatch two, non
> flat, patches without a seam. To get an idea of what I'm trying run the included
> scene.
> 
> Have been looking at the output of sPatch, but I'm still clueless.
> 
> ingo
> --

In October last year Vidar Maddsen asked something similiar. I created a
small scene where I attached two patches. 
The most important thing to understand is that only the four cornerpoint
represent positions of the patch while the rest tells where the 'curve
(spline)' is heading to. In order to get a seamless connection all four
points of seam have to be the same for both patches. In the follwing
example this are the last line of the blue and the first line of the red
patch.
I hopt this one helps:


camera {
 rotate <0,180,0>
 location <7,5,3>
 look_at  <1.5,0,3>
 angle 60
}

light_source { <1.5,9,1.5> color rgb <1.0.0>}


plane {y,-4 pigment {checker rgb<1,1,1>, rgb <0.5,0.5,0.5>}}

//blue patch
bicubic_patch {
  type 1
  flatness 0.01
  u_steps 10
  v_steps 10
  <0.0, 0.0, 0.0>, <0.0, 0.5, 0.0>, <3.0, 0.5, 0.0>, <3.0, 0.0, 0.0>,
  <0.0, 0.5, 1.0>, <0.0, 3.0, 1.0>, <3.0, 3.0, 1.0>, <3.0, 0.5, 1.0>,
  <0.0, 0.5, 2.0>, <0.0, 3.0, 2.0>, <3.0, 3.0, 2.0>, <3.0, 0.5, 2.0>,
  <0.0, 0.0, 3.0>, <0.0, 0.5, 3.0>, <3.0, 0.5, 3.0>, <3.0, 0.0, 3.0>  //
<-+
  pigment {color rgb <0,0,1> } 					      //   |
  }								      //   |s
								      //   |a
                           					      //   |m
//red patch							      //   |e
bicubic_patch {							      //   |  type 1							      	      //   |l
  flatness 0.01  						      //   |i
  u_steps 10							      //   |n
  v_steps 10							      //   |e
  <0.0, 0.0, 3.0>, <0.0, 0.5, 3.0>, <3.0, 0.5, 3.0>, <3.0, 0.0, 3.0>, //
<-+
  <0.0, -0.5, 4.0>, <0.0, -2.0, 4.0>, <3.0, -2.0, 4.0>, <3.0, -0.5,
4.0>,
  <0.0, -0.5, 5.0>, <0.0, -2.0, 5.0>, <3.0, -2.0, 5.0>, <3.0, -0.5,
5.0>,
  <0.0, 0.0, 6.0>, <0.0, 0.5, 6.0>, <3.0, 0.5, 6.0>, <3.0, 0.0, 6.0>
  pigment {color rgb <1,0,0> }
  }


Marc
-- 
Marc Schimmler


Post a reply to this message

From: Marc Schimmler
Subject: Re: Q: smooth union of bezier patches
Date: 29 Apr 1999 05:56:27
Message: <37281EBA.F180EE0F@ica.uni-stuttgart.de>
Arghh, I messed it up while editing, but I'm sure you can fix it! :-)

Marc
-- 
Marc Schimmler


Post a reply to this message

<<< Previous 10 Messages Goto Initial 10 Messages

Copyright 2003-2023 Persistence of Vision Raytracer Pty. Ltd.