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On 3 Jun 1999 09:27:09 -0500, par### [at] fwi com (Ron Parker) wrote:
<snip>
>All of these ideas, with the possible exception of the falloff
>stuff, are very easy to implement. The crystalline lattice
>could be implemented as yet another patch to the crackle
>pattern - I would say a syntax something like
>
>crackle {
> centers {2, <0,0,0>, <.5,.5,.5>}
>}
>
>but with a better keyword than "centers", of course. I had thought
>at one time of making crackle 2d as well, but with the planar warp in
>the new superpatch such a thing is redundant.
The syntax I suggest is the following:
lattice3
{
Number_of_vertices, <vertex1> [, <vertex2>] ... [<vertex_max>]
[frequency <vector>]
[falloff_function [falloff_modifiers]]
}
Number_of_vertices is a float specifying the number of vertices per
lattice cell.
vertex1, vertex2 ... vertex_max are the 3D position vectors of the
lattice vertices. They should be situated within the unit cube. To
ensure this, the x, y and z components of a vector are calculated in
modulo 1, i.e. only the part of the number to the right of the decimal
point is considered, and 1 is added to negative numbers. For example
5.22357512 becomes 0.22357512 and -0.651 becomes 0.349 . This
calculation is invisible to the user and make the syntax easier to use
as it allows the user to place vertices wherever he/she likes.
The optional frequency vector specifies how many times the lattice
pattern should fit into the unit cube in each of the directions. This
is not the same as scaling the pattern by this amount if the
components of the frequency vector aren't all the same.
The optional falloff function should specify what law is applied to
map distance from the nearest vertex (edge? How exactly does crackle
work? I think it's vertex) to position in the map (color_map,
texture_map, /etc)
Peter Popov
ICQ: 15002700
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