Does anyone have a suggestion as to how I can get
media to show in a helix pattern?

Media in spheresweeps works fine as long as I use a constant density.

Are there any density functions that might work?

Thanks

Gail
*******************************************************************
* gsh### [at] monotixcoza              * ERROR: COFFEE.COM not found  *
* http://www.rucus.ru.ac.za/~gail/ * Insert cup and press any key *
*******************************************************************
   My Software never has bugs, It just develops random features
*******************************************************************

Post a reply to this message

You mention sphere sweeps, are you using the SuperPatch? If so, I
think you could come up with a function pattern (like atan(z/x), for
example) or a limited  Taylor series expansion thereof (depends which
one will be faster). If not, consider using the density_file pattern.


Peter Popov
ICQ: 15002700

Post a reply to this message

Peter Popov wrote in message ...
>You mention sphere sweeps, are you using the SuperPatch? If so, I
>think you could come up with a function pattern (like atan(z/x), for
>example) or a limited  Taylor series expansion thereof (depends which
>one will be faster). If not, consider using the density_file pattern.
>


Yes, I'm using superpatch.

Could you explain more about function patterns and density_file please,
that or point me at some documentation/tutorials. I haven't run across
those before.

Gail
*******************************************************************
* gsh### [at] monotixcoza              * ERROR: COFFEE.COM not found  *
* http://www.rucus.ru.ac.za/~gail/ * Insert cup and press any key *
*******************************************************************
   My Software never has bugs, It just develops random features
*******************************************************************

Post a reply to this message

Gail Shaw <gsh### [at] monotixcoza> wrote:
: Does anyone have a suggestion as to how I can get
: media to show in a helix pattern?

  Tried the spiral1 pattern already?

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

Post a reply to this message

On Fri, 3 Sep 1999 08:05:26 +0200, "Gail Shaw" <gsh### [at] monotixcoza>
wrote:

>Yes, I'm using superpatch.
>
>Could you explain more about function patterns and density_file please,
>that or point me at some documentation/tutorials. I haven't run across
>those before.

Every pattern is a function which takes (x,y,z) as a parameter and
returns a float clipped to the range [0.,1.], which is then used to
extract the necessary color / pigment / texture / normal from the
appropriate map. In official POV these functions have names such as
wood and marble. The SuperPatch offers a way to add custom patterns
without the need to recompile POV. You just type in the function of
x,y,z and that is it. The actual syntax is unclear to me since I have
only used the SuperPatch once.

A density_file (.df3) is a sort of a 3D grayscale 8 bits/pixel bitmap.
Think of it as pixel (voxel, actually) layers stacked in the +z
direction. As a pattern, it fits into a box { 0, 1 } and returns the
corresponding x,y,z brightness, interpolated if specified.

To make a density_file you need all the image layers. You can render
an animation, bearing in mind that the images are stacked in the +z
direction. You can then use PoD's tga2df3 utility (posted in p.b.u) if
you're using MS-Dos (or Win) or an emulation thereof.

> Gail


Peter Popov
ICQ: 15002700

Post a reply to this message

Please see p.b.i for a helixical media image produced with the
density_file method. Source will go to p.b.s-f in a few minutes.


Peter Popov
ICQ: 15002700

Post a reply to this message