POV-Ray : Newsgroups : povray.general : Smooth Pipes that won't crush! (newbie question , just piped up)) Server Time
4 Nov 2024 19:17:01 EST (-0500)
  Smooth Pipes that won't crush! (newbie question , just piped up)) (Message 1 to 8 of 8)  
From: Paul Brown
Subject: Smooth Pipes that won't crush! (newbie question , just piped up))
Date: 17 Sep 1999 19:54:30
Message: <37e2d4b6@news.povray.org>
I am looking for a utility that will allow me to generate things like pipes,
cup/mug handles etc.
An example of the sort of thing I am looking for is Piper by Mike Weber
(http://www.geocities.com/SiliconValley/Pines/8625/piper/piper.html)

This is an excellent utility which allows you to draw a path with Bsplines
using a simple 3d editor and then allows you to "Pipe" the path. The
resulting pipe is a raw triangle mesh. The pipe can be bent around quite
sharp corners without the pipe cross section being "crushed" (the pipe
radius remains fairly constant).

All this is fine but I need SMOOTH pipes without the underlying triangle
mesh showing though. Even converting the data from "raw" "raw smoothed" did
not help much.

All this would seem to point to using Bezier patch type objects (say  a
cylinder type patch in Moray or Spatch) and then bending and stretching this
into shape using rotations & translations etc.

The problem with this is it's tricky to keep the "pipe" diameter constant
after all that bending & stretching.
It ends up looking more like ribbon then pipe!

Any Ideas? Do I just have to "tough it out" with patch editors or has
someone written something like Piper but for patch type cylinders?

As a newbie this is my first post, so be kind.
(Or I might regret "piping up" :-)  )

Regards,
Paul Brown (New POVer)


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From: Ken
Subject: Re: Smooth Pipes that won't crush! (newbie question , just piped up))
Date: 17 Sep 1999 20:23:10
Message: <37E2DB02.D2723E74@pacbell.net>
Paul Brown wrote:
> 
> I am looking for a utility that will allow me to generate things like pipes,
> cup/mug handles etc.
> An example of the sort of thing I am looking for is Piper by Mike Weber
> (http://www.geocities.com/SiliconValley/Pines/8625/piper/piper.html)
> 
> This is an excellent utility which allows you to draw a path with Bsplines
> using a simple 3d editor and then allows you to "Pipe" the path. The
> resulting pipe is a raw triangle mesh. The pipe can be bent around quite
> sharp corners without the pipe cross section being "crushed" (the pipe
> radius remains fairly constant).
> 
> All this is fine but I need SMOOTH pipes without the underlying triangle
> mesh showing though. Even converting the data from "raw" "raw smoothed" did
> not help much.
> 
> All this would seem to point to using Bezier patch type objects (say  a
> cylinder type patch in Moray or Spatch) and then bending and stretching this
> into shape using rotations & translations etc.
> 
> The problem with this is it's tricky to keep the "pipe" diameter constant
> after all that bending & stretching.
> It ends up looking more like ribbon then pipe!
> 
> Any Ideas? Do I just have to "tough it out" with patch editors or has
> someone written something like Piper but for patch type cylinders?
> 
> As a newbie this is my first post, so be kind.
> (Or I might regret "piping up" :-)  )
> 
> Regards,
> Paul Brown (New POVer)

There are a couple of ways that you do this that vary from easy to difficult.

Chris Colefax offers two such methods-

  His spline.inc file which when the points that lay along the spline are
specified will handle the construction between the points. One of the most
powerful methods you may employ.

  His bend.inc file which will bend an existing cylinder- Has a penalty in
speed and bend radius.

http://www.geocities.com/SiliconValley/Lakes/1434/


  Ron Parker offers the torspline macro which is made for duty like
this and operates in a manner similar to that of Chris's macro though
has less flexibility. I would suggest you look into this one first
because it is well suited to what you are trying to do.

http://www2.fwi.com/~parkerr/traces.html


 You may also wish to take a look at this page. I'll leave the description
up to the page owner who provides examples of it's capabilities.

http://members.xoom.com/dvarrazzo/epov.htm

  Next on the list is a cool include file by Gilles Tran which is
an odd pipe making macro that can only be seen to be appreciated.
You can see an example of it in use in a recent submission by Gilles
called "Eve's first morning" posted recently in the images group and
on his home page.

http://www.mediaport.net/Artichaud/Tran/sources/gtsrcee.htm


  There is also a macro called connect by John van Sickle that allows
you to specify points along a spline and will connect them with cones
( you provide the spheres at the intersecting points). This one while
useful requires a lot of points to make smooth transitions. It is very
much like the program CTDS of old if you are familiar with that little
utility.

http://www.erols.com/vansickl/

If none of these suit your purposes then look to my links page and
explore your heart out. There is bound to be something there I missed.
Probably some of the animation utilities and actual programs sections.


-- 
Ken Tyler

See my 1000+ Povray and 3D Rendering and Raytracing Links at:
http://home.pacbell.net/tylereng/index.html


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From: Chris Colefax
Subject: Re: Smooth Pipes that won't crush! (newbie question , just piped up))
Date: 17 Sep 1999 21:29:10
Message: <37e2eae6@news.povray.org>
Paul Brown <pau### [at] pabcomfreeservecouk> wrote:
> I am looking for a utility that will allow me to generate things like
pipes,
> cup/mug handles etc.
> An example of the sort of thing I am looking for is Piper by Mike Weber
> (http://www.geocities.com/SiliconValley/Pines/8625/piper/piper.html)
>
> This is an excellent utility which allows you to draw a path with Bsplines
> using a simple 3d editor and then allows you to "Pipe" the path. The
> resulting pipe is a raw triangle mesh. The pipe can be bent around quite
> sharp corners without the pipe cross section being "crushed" (the pipe
> radius remains fairly constant).
>
> All this is fine but I need SMOOTH pipes without the underlying triangle
> mesh showing though. Even converting the data from "raw" "raw smoothed"
did
> not help much.
>
> All this would seem to point to using Bezier patch type objects (say  a
> cylinder type patch in Moray or Spatch) and then bending and stretching
this
> into shape using rotations & translations etc.
>
> The problem with this is it's tricky to keep the "pipe" diameter constant
> after all that bending & stretching.
> It ends up looking more like ribbon then pipe!
>
> Any Ideas? Do I just have to "tough it out" with patch editors or has
> someone written something like Piper but for patch type cylinders?

Ken has already provided a link to my (thoroughly obsolete!) Spline include
file, although I would hardly recommend it for your purposes.  However, as I
describe on my Current Projects page the task that's monopolised my
attention of late is a completely rewritten Spline macro system.  Much of
the work has gone into spline design functions not generally available in
other programs, but the other focus has certainly been on automating the
creation of spline-based objects.

One thing I have tried to avoid is using triangle meshes: while these have
their place in raytracing, I really don't see them as the most suitable
option.  Instead, I've created macros for pipe splines (using joined
cylinders/cones/spheres) and blob splines (using stretched and orientated
spherical blob components).  In both cases the results are memory efficient
and faster to render than, say, similar sphere sweeps.  The blobs, being
particular suited to raytracing, give very good results for most path shapes
and are much faster in CSG operations than the standard cylinders and
spheres.

You can also create objects by joining links along the length of the spline
(suitable for many types of hoses, chains, tracks, etc).  In all cases, you
can apply vector scaling, rotation, and translation to the spline path
itself without affecting the cross section of the objects you create.
Before I release the file I want to add some extra spline object macros,
such as coiled splines (telephone cable, anyone?) and perhaps ribbon-type
splines (using optimised Bezier patches) and the ability to bend an existing
object along a spline...


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From: Alan Kong
Subject: Re: Smooth Pipes that won't crush! (newbie question , just piped up))
Date: 18 Sep 1999 02:49:55
Message: <iDTjN=ME2T0ZnHs4ADumc1Zjg=aO@4ax.com>
On Sat, 18 Sep 1999 00:54:37 +0100, "Paul Brown"
<pau### [at] pabcomfreeservecouk> wrote:

>The problem with this is it's tricky to keep the "pipe" diameter constant
>after all that bending & stretching.

  Hi, Paul. If you are using the Windows platform there is the unofficial
version of POV-Ray called Superpatch, compiled by Ron Parker. It has a patch
called sphere sweeps, by Jochen Lippert. It can generate smooth pipes with a
constant cross-section at the bends.

http://www2.fwi.com/~parkerr/superpatch/

  Jochen Lippert also has a tutorial page but I cannot recall the .url.

-- 
Alan ---------------------------------------------------------------
http://www.povray.org - Home of the Persistence of Vision Ray Tracer
news.povray.org - where POV-Ray enthusiasts around the world can get
together to exchange ideas, information, and experiences with others


Post a reply to this message

From: Ken
Subject: Re: Smooth Pipes that won't crush! (newbie question , just piped up))
Date: 18 Sep 1999 03:46:33
Message: <37E342E8.9F7BE765@pacbell.net>
Alan Kong wrote:

>   Jochen Lippert also has a tutorial page but I cannot recall the .url.

http://www.informatik.uni-bremen.de/~vader/pss/pss.html

-- 
Ken Tyler

See my 1000+ Povray and 3D Rendering and Raytracing Links at:
http://home.pacbell.net/tylereng/index.html


Post a reply to this message

From: Paul Brown
Subject: Re: Smooth Pipes that won't crush! (newbie question , just piped up))
Date: 18 Sep 1999 17:50:50
Message: <37e4093a@news.povray.org>
Thanks for all the help chaps. I will let you know how I get on.
What a great community.
Regards.
Paul Brown


Post a reply to this message

From: Alan Kong
Subject: Re: Smooth Pipes that won't crush! (newbie question , just piped up))
Date: 18 Sep 1999 23:05:11
Message: <ok7kN72qdL7m5L4MENanst9Mgoq1@4ax.com>
On Sat, 18 Sep 1999 00:44:40 -0700, Ken <tyl### [at] pacbellnet> wrote:

>http://www.informatik.uni-bremen.de/~vader/pss/pss.html

  Thanks, Ken. I've got to bookmark this one.

-- 
Alan ---------------------------------------------------------------
http://www.povray.org - Home of the Persistence of Vision Ray Tracer
news.povray.org - where POV-Ray enthusiasts around the world can get
together to exchange ideas, information, and experiences with others


Post a reply to this message

From: John M  Dlugosz
Subject: Re: Smooth Pipes that won't crush! (newbie question , just piped up))
Date: 23 Sep 1999 21:28:12
Message: <37ead3ac@news.povray.org>
Suggestion:  use a sphere sweep (in the Superpatch) or a bunch of cylinders
following the path, like the rope macro does.

Paul Brown <pau### [at] pabcomfreeservecouk> wrote in message
news:37e2d4b6@news.povray.org...
> I am looking for a utility that will allow me to generate things like
pipes,
> cup/mug handles etc.
> An example of the sort of thing I am looking for is Piper by Mike Weber
> (http://www.geocities.com/SiliconValley/Pines/8625/piper/piper.html)
>
> This is an excellent utility which allows you to draw a path with Bsplines
> using a simple 3d editor and then allows you to "Pipe" the path. The
> resulting pipe is a raw triangle mesh. The pipe can be bent around quite
> sharp corners without the pipe cross section being "crushed" (the pipe
> radius remains fairly constant).
>
> All this is fine but I need SMOOTH pipes without the underlying triangle
> mesh showing though. Even converting the data from "raw" "raw smoothed"
did
> not help much.
>
> All this would seem to point to using Bezier patch type objects (say  a
> cylinder type patch in Moray or Spatch) and then bending and stretching
this
> into shape using rotations & translations etc.
>
> The problem with this is it's tricky to keep the "pipe" diameter constant
> after all that bending & stretching.
> It ends up looking more like ribbon then pipe!
>
> Any Ideas? Do I just have to "tough it out" with patch editors or has
> someone written something like Piper but for patch type cylinders?
>
> As a newbie this is my first post, so be kind.
> (Or I might regret "piping up" :-)  )
>
> Regards,
> Paul Brown (New POVer)
>
>
>
>


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