Christoph Hormann wrote:

> This would be really nice for roads, rails, etc. following a terrain
> surface in height and slope

Good ideas !

Thank you.

> (for example using megapov's hf_height_at
> feature).

Sounds interesting. Does that feature allow one to
"wrap" a height field around any shape ?

> I am waiting for a public version :)

I'm working on it. And I'll post it when it's finished.

If you're interested in having a look at some preliminary
code, you can peek at the code I am about to post.


Tor Olav
--
mailto:tor### [at] hotmailcom
http://www.crosswinds.net/~tok/tokrays.html

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This image shows how the "Twisted" lathe shapes are assembled
from several lathe segments.

This time I entered the 2D co-ordinates for the red lathe shape
(linear_spline) by hand into an array. The yellow spheres shows
where these points "travels" in 3D for each lathe segment.

The blue shape shows how similar things can by achieved with
cylinders. (I think there are some macros out there for doing
different kinds of cylinder "spaghetti".)

The cyan cylinders represents the axes that the different
segments are turned "around". (They are of coarse created at
origo and then tilted and translated to their final positions.)

The transition from one segment to another always happens in a
plane. And the rotation centres of both these segments also
have to lie in this plane.

At this moment my macro takes an array of such planes as an
argument together with the initial array of 2D points for the
lathe. It also needs a 3D reference point; ("Origo" for the 2D
co-ordinates) that "walks" from line to line (magenta spheres).

For every subsequent pair of planes in the array of planes it
calculates the lines I mentioned above. (These lines are the
intersections of each subsequent pair of planes.)

Currently I am investigating possible methods for gaining a
more intuitive control over the final shape.

There are several possible methods, but finding a good one is
not easy (for me). (And if everything else "fails", I may have
to use iterative numerical methods to help the users achieving
a path as close as possible to their "wish"-path.)


Tor Olav
--
mailto:tor### [at] hotmailcom
http://www.crosswinds.net/~tok/tokrays.html

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Attachments:
Download 'lathemacro05_10_03.jpg' (66 KB)

Preview of image 'lathemacro05_10_03.jpg'

Tor Olav Kristensen wrote:

> The blue shape shows how similar things can by achieved with
> cylinders.

Ehh... I meant torii.

Sorry.


Tor Olav
--
mailto:tor### [at] hotmailcom
http://www.crosswinds.net/~tok/tokrays.html

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Tor Olav Kristensen wrote:
> 
> > (for example using megapov's hf_height_at
> > feature).
> 
> Sounds interesting. Does that feature allow one to
> "wrap" a height field around any shape ?
> 

No, it just gives back the height at a specific point, allowing
automatic placement of objects on the surface.  

Christoph

--
Christoph Hormann <chr### [at] gmxde>
Homepage: http://www.schunter.etc.tu-bs.de/~chris/

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it looks nicely complicated, well done !!

Rick

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Serge LAROCQUE wrote:

> I am reminded of a Simpsons episode (everything reminds of a Simpsons episode
> ;) ) in which someone mentioned a Play Doh factory, then they showed it, there
> was a giant ruler with holes of various shapes (star, triangle, etc). Then the
> foreman called for a "Crescent moon, crescent moon", and you would see it
> squeeze through the crescent-moon-shaped hole and go onto a waiting truck :-)

Sorry. I like the Simpsons, but I haven't seen more
than a few Simpsons episodes.

I can imagine that squeezing something soft through
different shaped holes would create similar shapes to
my "Twisted" shapes.

But I'm afraid that since I'm not a native speaker of
english, there may be something in the humour in the
episode you mention that I don't understand.  :(

E.g.: Are there any US-word games in there ?

And what is Play Doh ?


Tor Olav
--
mailto:tor### [at] hotmailcom
http://www.crosswinds.net/~tok/tokrays.html

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Rick wrote:

> it looks nicely complicated, well done !!
>
> Rick

Makes me smile. Because I have never thought that
anything could be described as "nicely complicated".

Thanks.


Tor Olav
--
mailto:tor### [at] hotmailcom
http://www.crosswinds.net/~tok/tokrays.html

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"Tor Olav Kristensen" <tto### [at] onlineno> wrote in message
news:393DB5D9.EE109890@online.no...
|
| Serge LAROCQUE wrote:
|
| > I am reminded of a Simpsons episode (everything reminds of a Simpsons
episode
| > ;) ) in which someone mentioned a Play Doh factory
|
| Sorry. I like the Simpsons, but I haven't seen more
| than a few Simpsons episodes.
|
| I can imagine that squeezing something soft through
| different shaped holes would create similar shapes to
| my "Twisted" shapes.
|
| But I'm afraid that since I'm not a native speaker of
| english, there may be something in the humour in the
| episode you mention that I don't understand.  :(
|
| E.g.: Are there any US-word games in there ?
|
| And what is Play Doh ?

If I had said it (Play Dough) you might have understood better then  :-)
Something I'm not sure was noticed here is that Homer Simpson is famous for
his remarking "Doh!" all the time.
The Play Doh factory thing must have been a vision someone was thinking, a
childs toy turned into real place kind of thing.

Bob

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Last week I wrote that I were about to post
the source code for this image.

Unfortunately I have been so busy with other 
projects, that I have not had time to clean
up my code and post it. Sorry.

I have now posted it to:

news:povray.text.scene-files


Tor Olav
--
mailto:tor### [at] hotmailcom
http://www.crosswinds.net/~tok/tokrays.html

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