Hi,
  I remember a long time ago when someone made a macro for hairs along an
object.  Well, I would be in need of such thing, but I need them not to be
hairs, and not on a sphere, but more like a blob and cylinders, cones... etc...

Thanks for any info,
  Simon

-- 
+--------------------------------+---------------------------+
| Simon Lemieux                  | http://666Mhz.myip.org/   |
| Email : lem### [at] yahoocom | Povray and OpenGL Gallery |
+--------------------------------+---------------------------+

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Simon Lemieux <lem### [at] yahoocom> wrote:
>   I remember a long time ago when someone made a macro for hairs along an
> object.  Well, I would be in need of such thing, but I need them not to be
> hairs, and not on a sphere, but more like a blob and cylinders, cones...
etc...

I do have a Hair Generator that works with my Compressed Mesh macro file:

    http://www.geocities.com/ccolefax/pcm.hrml

This operates on compressed triangle meshes or bicubic patches (as created
by Warp's Mesh Compressor), but it can be used to create many things besides
hair (such as scales, grass, bubbles, etc).  And the ideas in the file could
be adapted to use MegaPOV's trace function, if you don't want to convert
your objects to triangle meshes...

Post a reply to this message

> I do have a Hair Generator that works with my Compressed Mesh macro file:
> 
>     http://www.geocities.com/ccolefax/pcm.html
> 
> This operates on compressed triangle meshes or bicubic patches (as created
> by Warp's Mesh Compressor), but it can be used to create many things besides
> hair (such as scales, grass, bubbles, etc).  And the ideas in the file could
> be adapted to use MegaPOV's trace function, if you don't want to convert
> your objects to triangle meshes...

It seems exactly what I need, but I was wondering if the hair could have a
personnal color_map applied?  And how can I convert my blob into a mesh object?

Thanks,
  Simon

-- 
+--------------------------------+---------------------------+
| Simon Lemieux                  | http://666Mhz.myip.org/   |
| Email : lem### [at] yahoocom | Povray and OpenGL Gallery |
+--------------------------------+---------------------------+

Post a reply to this message

Simon Lemieux <lem### [at] yahoocom> wrote:
> It seems exactly what I need, but I was wondering if the hair could have a
> personnal color_map applied?  And how can I convert my blob into a mesh
object?

The macro file includes a number of texturing options, including the ability
to assign a pigment map to the hair so that each hair takes on the colour of
the map at the point from which it grows (rather than simply applying a
texture to the union of hair objects after they have been placed).

To convert arbitrary objects to a mesh (tessellation) your best bet is
probably Ron's trace function - I believe a macro was created to do this
(TriScan).  Check the POV Links for a download...

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Chris Colefax <chr### [at] tagpovrayorg> wrote:
: To convert arbitrary objects to a mesh (tessellation) your best bet is
: probably Ron's trace function - I believe a macro was created to do this
: (TriScan).  Check the POV Links for a download...

  I have made a tesselation patch but its development has been frozen
because of an annoying bug which seems impossible to overcome in any
rational way.
  It's also a bit outdated as it's built over MegaPov 0.6a source.

http://www.cs.tut.fi/~warp/TesselationPatch/

-- 
#macro N(D,I)#if(I<6)cylinder{M()#local D[I]=div(D[I],104);M().5,2pigment{
rgb M()}}N(D,(D[I]>99?I:I+1))#end#end#macro M()<mod(D[I],13)-6,mod(div(D[I
],13),8)-3,10>#end blob{N(array[6]{11117333955,
7382340,3358,3900569407,970,4254934330},0)}//                     - Warp -

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Chris Colefax wrote:
> 
> Simon Lemieux <lem### [at] yahoocom> wrote:
> > And how can I convert my blob into a mesh object?
> 
> 
> To convert arbitrary objects to a mesh (tessellation) your best bet is
> probably Ron's trace function - I believe a macro was created to do this
> (TriScan).  Check the POV Links for a download...

Until the tesselation patch is finished... but it seems the thread died...
and the patch is not finished yet... See p.u.p, around january 2001

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: Until the tesselation patch is finished... but it seems the thread died...
: and the patch is not finished yet... See p.u.p, around january 2001

  It has an annoying bug which doesn't seem to be related to the patch
itself (that is, the bug doesn't seem to be in the patch code) but it's
most probably related to some odd way of working of intersection tests
and/or meshes. I haven't got any idea on how it should be fixed (and no-one
else either, not even people who know the POV-Ray source very well).
  Some possible fixes have been presented, but I haven't liked them. Usually
these fixes have the effect that some (or even most of the) triangles are
not connected to the adjacent ones, which in practice makes the mesh consist
of separate triangles.
  I also don't like them because they don't explain why the problem happens,
but are more or less "kludges" around it. I would like to know the exact
reason of the bug and then understand how it could be fixed or why it can't
be fixed at all.

-- 
#macro N(D,I)#if(I<6)cylinder{M()#local D[I]=div(D[I],104);M().5,2pigment{
rgb M()}}N(D,(D[I]>99?I:I+1))#end#end#macro M()<mod(D[I],13)-6,mod(div(D[I
],13),8)-3,10>#end blob{N(array[6]{11117333955,
7382340,3358,3900569407,970,4254934330},0)}//                     - Warp -

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>   It has an annoying bug which doesn't seem to be related to the patch
> itself (that is, the bug doesn't seem to be in the patch code) but it's
> most probably related to some odd way of working of intersection tests
> and/or meshes. I haven't got any idea on how it should be fixed (and no-one
> else either, not even people who know the POV-Ray source very well).
>   Some possible fixes have been presented, but I haven't liked them. Usually
> these fixes have the effect that some (or even most of the) triangles are
> not connected to the adjacent ones, which in practice makes the mesh consist
> of separate triangles.
>   I also don't like them because they don't explain why the problem happens,
> but are more or less "kludges" around it. I would like to know the exact
> reason of the bug and then understand how it could be fixed or why it can't
> be fixed at all.

Then, what would you suggest if I'm using Pov3.1 on linux?
I don't wish to upgrade my current version of pov to anything other than
official povray...

Thanks,
  Simon

-- 
+--------------------------------+---------------------------+
| Simon Lemieux                  | http://666Mhz.myip.org/   |
| Email : lem### [at] yahoocom | Povray and OpenGL Gallery |
+--------------------------------+---------------------------+

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Simon Lemieux <lem### [at] yahoocom> wrote:

> Then, what would you suggest if I'm using Pov3.1 on linux?
> I don't wish to upgrade my current version of pov to anything other than
> official povray...

Well...wait for POV 3.5. Or do it by hand, or write your own
intersection functions as POV macros...


-- 
Christopher James Huff - chr### [at] maccom
Home Page: http://homepage.mac.com/chrishuff/
POV-Ray TAG e-mail: chr### [at] povrayorg
POV-Ray TAG web site: http://tag.povray.org/

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> Well...wait for POV 3.5. Or do it by hand, or write your own
> intersection functions as POV macros...

Until POV 3.5, I think I'll find another way around! ;)

Thanks,
  Simon

-- 
+--------------------------------+---------------------------+
| Simon Lemieux                  | http://666Mhz.myip.org/   |
| Email : lem### [at] yahoocom | Povray and OpenGL Gallery |
+--------------------------------+---------------------------+

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