I've been thinking it possible to create paper models of some of my meshes,
by printing out the individual triangles on paper and glueing them together.
It would probably be easier to do this with triangle strips rather than
individual triangles, but that's a patience issue :-)

How would it be possible to 'unwrap' a triangle mesh, so that the position
of each triangle could be known, and a plan created to allow the paper
triangles to be stuck together in the correct positions?

I have seen triangle to strip converters etc, but I can't work out how to do
this properly. And I can't seem to find any tutorials or algorithms on this?
But would it be similar to how Steve Cox's UVMapper works?

Post a reply to this message

Geez I need help.
After spending all yesterday writing a program to create tristrips, I
realised that was about 1000 times more work than needed for what I want to
do.
Now, I can rotate a triangle - specifically the points of a triangle - in
povray so that all points lie in the plane z=0. I did this with Margus
Ramst's v_reorient macro. No worries there. But I need a pascal routine to
do the same thing so I can print the triangles.

Problem: how the hell do I code the built-in vaxis_rotate function in
pascal?
I know it's simple - I did it several times last year for another project.
But I just can not get it to work today, even after reading the matrix
tutorial. I'm confusing myself between rotating an object, and rotating a
position vector, around an arbitrary axis. I just can not get this, and I
did linear algebra at Uni several years ago. Depression's not helping, I
guess :-(

So, I now couldn't give a stuff about the theory. I just need some
pseudocode, or pascal/c source to do this...please?
And yes, I have the pov source, just can't follow multi-function c code at
the moment.

When you can write a program to create tristrips in a couple of hours, and
then have trouble rotating a few points around a couple of straight lines,
you know you're sick in the head <attempted grin>.

Dave.


"jarbee" <d_j### [at] yahoocom> wrote in message
news:3bae4270@news.povray.org...
> I've been thinking it possible to create paper models of some of my
meshes,
> by printing out the individual triangles on paper and glueing them
together.
> It would probably be easier to do this with triangle strips rather than
> individual triangles, but that's a patience issue :-)
>
> How would it be possible to 'unwrap' a triangle mesh, so that the position
> of each triangle could be known, and a plan created to allow the paper
> triangles to be stuck together in the correct positions?
>
> I have seen triangle to strip converters etc, but I can't work out how to
do
> this properly. And I can't seem to find any tutorials or algorithms on
this?
> But would it be similar to how Steve Cox's UVMapper works?
>
>

Post a reply to this message

Sorry everyone. All I had to do was look at Paul Bourke's page.
I'm going to therapy now :-)

Dave

"jarbee" <d_j### [at] yahoocom> wrote in message
news:3bb014f5@news.povray.org...
> Geez I need help.
> After spending all yesterday writing a program to create tristrips, I
> realised that was about 1000 times more work than needed for what I want
to
> do.
> Now, I can rotate a triangle - specifically the points of a triangle - in
> povray so that all points lie in the plane z=0. I did this with Margus
> Ramst's v_reorient macro. No worries there. But I need a pascal routine to
> do the same thing so I can print the triangles.
>
> Problem: how the hell do I code the built-in vaxis_rotate function in
> pascal?
> I know it's simple - I did it several times last year for another project.
> But I just can not get it to work today, even after reading the matrix
> tutorial. I'm confusing myself between rotating an object, and rotating a
> position vector, around an arbitrary axis. I just can not get this, and I
> did linear algebra at Uni several years ago. Depression's not helping, I
> guess :-(
>
> So, I now couldn't give a stuff about the theory. I just need some
> pseudocode, or pascal/c source to do this...please?
> And yes, I have the pov source, just can't follow multi-function c code at
> the moment.
>
> When you can write a program to create tristrips in a couple of hours, and
> then have trouble rotating a few points around a couple of straight lines,
> you know you're sick in the head <attempted grin>.
>
> Dave.
>
>
> "jarbee" <d_j### [at] yahoocom> wrote in message
> news:3bae4270@news.povray.org...
> > I've been thinking it possible to create paper models of some of my
> meshes,
> > by printing out the individual triangles on paper and glueing them
> together.
> > It would probably be easier to do this with triangle strips rather than
> > individual triangles, but that's a patience issue :-)
> >
> > How would it be possible to 'unwrap' a triangle mesh, so that the
position
> > of each triangle could be known, and a plan created to allow the paper
> > triangles to be stuck together in the correct positions?
> >
> > I have seen triangle to strip converters etc, but I can't work out how
to
> do
> > this properly. And I can't seem to find any tutorials or algorithms on
> this?
> > But would it be similar to how Steve Cox's UVMapper works?
> >
> >
>
>
>
>

Post a reply to this message