Thanks to Mike Williams for, over the years, providing such a useful set of
macros such as SweepMesh. SweepMesh allows one to make a mesh2 object which is a
tube whose radius and centerline comply to a given set of splines. The natural
culmination is in his braided rope macro.

I have a new idea, and I don't know if it were an afternoon of coding for a
genius, or a topic that PhD students would have sweat through a dissertation
for.

Think of the current system as a "two hole" system. I'd like a "turtleneck
sweater" and a "pants" macro, or "four holes crossed" and "three hole: one going
to two" systems.

One way of providing inputs would be to have the user provide four splines--
left and right;  top of neck to end of sleeve, and sleeve underarm to waist.  It
might be remotely possible for me to do this "one time", but I'm fearful of
making one that allows for arbitrary spline inputs and number of triangles, and
be smooth.

Is this doable? Any tips on how to approach it?  (Or John vanSickle, do you have
any insights from your modeller that would make for an easy in-povray way to
design this?)

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in news:web.4c9b7b273beb987730bf98980@news.povray.org gregjohn wrote:

> Is this doable? Any tips on how to approach it?  (Or John vanSickle,
> do you have any insights from your modeller that would make for an
> easy in-povray way to design this?)

Greg, I think it may be doable with one of the macro's in my mesh 
generation package http://code.google.com/p/mmgm/ or Tor-Olavs NURBS 
macro's. All depends on how you brake down the trousers in a few basic 
shapes that can be defined by four splines that you then stich together.

I'll try to describe the brake down: one spline defines the outer seam of 
the trousers, at the lower end connected to a half circle spline for the 
"foot hole". The top of de seam sline is connected to a quarter circle 
that is the belt section of the trousers. Last spline would be the inner 
seam. These four splines define a surface that form a quarter of the 
trousers.

ingo

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ingo <ing### [at] tagpovrayorg> wrote:
> in news:web.4c9b7b273beb987730bf98980@news.povray.org gregjohn wrote:
>
> > Is this doable? Any tips on how to approach it?  (Or John vanSickle,
> > do you have any insights from your modeller that would make for an
> > easy in-povray way to design this?)
>
> Greg, I think it may be doable with one of the macro's in my mesh
> generation package http://code.google.com/p/mmgm/ or Tor-Olavs NURBS
> macro's. All depends on how you brake down the trousers in a few basic
> shapes that can be defined by four splines that you then stich together.
>
> I'll try to describe the brake down: one spline defines the outer seam of
> the trousers, at the lower end connected to a half circle spline for the
> "foot hole". The top of de seam sline is connected to a quarter circle
> that is the belt section of the trousers. Last spline would be the inner
> seam. These four splines define a surface that form a quarter of the
> trousers.
>
> ingo


ingo, thanks for thinking this through with me.  First of all upon looking at
your google code site (but not yet d/ling any files) I'm wondering which include
or routine it would be. I want to animate the splines, then generate meshes
inside povray.  And as you describe it, how is the transition from material that
is, say, the seat of pants, to to the upper leg?

I've got a macro where I modified Mike's code to take any arbitrary sectioning
shape-- superellipsoid, cube, squashed cylinder-- instead of a circle, as it
creates the mesh along the backbone. With it, I've made a mesh2 shape that
vaguely represents top of head to bottom of torso, it's just a "two hole"
structure.  I'm now thinking about the transition around the seat to sleeves.

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ingo <ing### [at] tagpovrayorg> wrote:
> in news:web.4c9b7b273beb987730bf98980@news.povray.org gregjohn wrote:
>
>
> Greg, I think it may be doable with one of the macro's in my mesh
> generation package http://code.google.com/p/mmgm/

Wow, It's great.

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in news:web.4c9de1639b1fb69134d207310@news.povray.org gregjohn wrote:

> ingo, thanks for thinking this through with me.  First of all upon
> looking at your google code site (but not yet d/ling any files) I'm
> wondering which include or routine it would be. 

Greg, it's been a while since I wrote and used the thing, so I had to look 
for my self. The multi spline mesh seems the best candidate to create one 
half of the trousers. Define the green and red splines in the attached 
image. The mesh package is fully documented and has examples.


> 
> I've got a macro where I modified Mike's code to take any arbitrary
> sectioning shape-- superellipsoid, cube, squashed cylinder-- instead
> of a circle, as it creates the mesh along the backbone. 

Writing a macro for Lofting / extruding a pair of trousers ie splitting a 
path (backbone) to go in different dirction isn't easy.

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Attachments:
Download 'pantssplines.png' (5 KB)

Preview of image 'pantssplines.png'

Thanks. I've posted to p.b.i. an image which is an attempt to try your
four-point coons.inc on the problem of pants.  I think that the coons include
will be more useful than the MMGM.  I'm also wondering if I should try a
six-point or eight-point modification of your macro to try and get the geometry
just right.

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Sorry,  msm.inc seemed a better application than coons.inc.

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