POV-Ray : Newsgroups : povray.advanced-users : Need a script to randomly scatter objects vertically : Re: Need a script to randomly scatter objects vertically Server Time
10 Dec 2023 12:33:37 EST (-0500)
  Re: Need a script to randomly scatter objects vertically  
From: Bald Eagle
Date: 13 May 2021 15:00:00
Message: <web.609d7610c2ce34cb1f9dae3025979125@news.povray.org>
Mike Horvath <mik### [at] gmailcom> wrote:

> Could I create a slope map or object pigment? That would be a lot
> smoother gradient I think than doing a few checks here and there using
> conditionals.

Not having implemented any of this in a working scene, I don't presently have
any practical knowledge of everything that's going on.  As it appeared to me,
there were a few pigments/functions that governed stuff, and a trace to get a
normal at a point.  I'm not sure why more maps or pigments would be required or
how they would be used.

If you're placing objects based on the sampling results of the ground plane /
heightfield, then the decision about what object to place and how would be done
in the loop.
Maybe there's a way to have several loops, but I think that would be less

As for an object pigment, there is NO gradient at all - or rather - an abrupt,
infinite gradient - a sudden discontinuity from inside to outside.  Bill
Pokorny, myself, and possibly others have experimented with sampling methods
geared toward creating an actual smooth gradient for the object pattern to
(IIRC) use it in isosurfaces.

> I would need to feed the 3D mesh into some function or macro and get a
> 2D pigment as output. Dunno how to do that.

You're gonna have to give me a sample image or a drawing that shows what the 3D
mesh is and what needs to go where and why - and then maybe I tell you how to
accomplish your goal.

You _can_ trivially turn your 3D mesh into a "2D" pigment by just using the mesh
as an object in an object pigment, or if you want that silhouette effect, using
an object pigment in a function, setting y to 0, and putting that back into a
pigment pattern....

But I'm presently just guessing / speculating about what your actual needs and
final goals are.

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