POV-Ray : Newsgroups : povray.unofficial.patches : Procedural texture help... Server Time
2 Sep 2024 04:13:07 EDT (-0400)
  Procedural texture help... (Message 1 to 3 of 3)  
From: Rich
Subject: Procedural texture help...
Date: 19 Jun 2000 22:19:47
Message: <8F58C3744spammindspringcom@204.213.191.228>
I'm posting this here as I have a hunch what I'm looking for can't be 
done in official POV-Ray.  I'm looking for any hint, tips, etc. in creating 
a procedural texture for huge space-station-type objects.  I have tried the 
HullTexture posted a while ago by (I think) H.E.Day (crackle with metric 1) 
but it doesn't work for the shapes I'm using.  I'd like to be able to have 
the texture surface wrap around stretched torii, spheres, _and_ bicubic 
patches created in SPatch.  I'm looking in the procedural direction because 
the texture needs to be clear no matter how far or close the camera is.
  Please, no 'alien skin' suggestions, I can do that just fine.  I need to 
create a texture that looks like it has been produced by human technology 
in the not-so-distant future.
  I have thought about using the uv-mapping, but I'm not sure exactly how 
it will help.  Using the uv-mapping keyword on the feeble attempts I've 
made so far have produced some strange results.
  I can post a picture of the largest object in bland grey if that would 
help with the suggestions.  <smile>  Thanks for any help!  Oh, I have the 
latest version of MegaPOV, so any feature of that great compilation will 
work.

-- 
Rich Allen
(Remove SPAM from my address to reply by e-mail)


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From: H E  Day
Subject: Re: Procedural texture help...
Date: 19 Jun 2000 23:21:00
Message: <394EE261.5F2FF308@heday.freeservers.com>
>   I'm posting this here as I have a hunch what I'm looking for can't be
> done in official POV-Ray.  I'm looking for any hint, tips, etc. in creating
> a procedural texture for huge space-station-type objects.

Hmm.  Let's see. I think I may be able to help you. :)

>  I have tried the HullTexture posted a while ago by (I think) H.E.Day
> (crackle with metric 1)
> but it doesn't work for the shapes I'm using.

Yeah, that's mine.

>  I'd like to be able to have the texture surface wrap around stretched torii,
> spheres, _and_ bicubic
> patches created in SPatch.  I'm looking in the procedural direction because
> the texture needs to be clear no matter how far or close the camera is.

Some thing you might want to look at:
The warp {shape} (where shape is a spherical, toroidal, or cylindrical warp)
Put this at the end of the pigment statement.  A word of warning, however.  You
MUST decrease the scale of the pigment before doing this.  For example:
scale <1,1,1/200>
warp {cylindrical}

will rotate the texture 200 times around the y axis.  If you have a long,
slight tubular spaceship to texture, you might consider this.

Also, Just leaving the texture "as is" (scaled perhaps <1,1,2>) is perfectly
cool and normal.  The look may be a bit confused (instead of just rectangles,
you get all sorts of polys) but you may grow to love it.

One thing I just though of:  Using the cylindrical warp with a model will
probably yield a "tightness" in the bow and aft.  To fix this, try this:

texture {
cylindrical
texture_map {
[.6667 Cylindrical_Texture_You_Made_Above]
[.75 Duplicate_Texture_Without_Cylindrial_Warp]
}
rotate 90*x //assumes the ship is oriented on the z axis
scale 2*z  //enhances the "sleekness" of the texture
}
Oh, one more thing:  for the two colors (or more) used in the HullTexture
pigment statement, make one a rust, i.e. <.8,.75,.7> and another a bluish
<.7,.75,.8> color.  This will add a great deal of sheer "character" to the
ship.


Do try to mess around with the ideas above.  They should yield rather
impressive results.



--
H.E. Day


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From: Rich
Subject: Re: Procedural texture help...
Date: 20 Jun 2000 23:03:17
Message: <8F59DF54Bspammindspringcom@204.213.191.228>
The### [at] hedayfreeserverscom (H.E. Day) wrote in
<394EE261.5F2FF308@heday.freeservers.com>: 

>Some thing you might want to look at:
>The warp {shape} (where shape is a spherical, toroidal, or cylindrical
>warp) Put this at the end of the pigment statement.  A word of warning,
>however.  You MUST decrease the scale of the pigment before doing this. 
>For example: scale <1,1,1/200>
>warp {cylindrical}

  Thanks!  The cylindrical warp has really helped, here is a butchered 
version of the HullTexture that I'm still fiddling with:

#declare HullTexture = texture { 
  pigment {
    crackle metric 1
    color_map {
      [0.0 rgb 0.6]
      [0.2 rgb <0.8,0.6,0.3>]
      [0.4 rgb <0.5,0.5,0.8>]
      [1.0 rgb 0.8]
    }
  } 
  scale .06
  warp {cylindrical}
}

  You can try it out on a torus, like so (from the middle of my space 
station):

torus  { 1.9, .5   scale <1,4.4,1> texture {HullTexture} }

WIP posted to images, I hope.  Any improvements will be very welcome!  

-- 
Rich Allen
(Remove SPAM from my address to reply by e-mail)


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