POV-Ray : Newsgroups : povray.binaries.utilities : Wireframe Generator (from meshes) Server Time 3 Jul 2022 23:31:06 EDT (-0400)
 Wireframe Generator (from meshes) (Message 1 to 1 of 1)
 From: CShake Subject: Wireframe Generator (from meshes) Date: 13 Jul 2010 11:37:46 Message: <4c3c884a@news.povray.org>

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"dateCreated": "2010-07-13T15:37:46+00:00",
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I've been working lately with a bunch of models exported from
milkshape3d to render higher quality versions of game objects, and
decided that finding a way to make a wireframe version of the model
should be possible. And without any existing things I could find via web

Attached is a php script that reads a given .inc file that contains all
the meshes and produces a new file with two macros for both edges and
vertices. The names for these come from the filename of the original
include file: for example, if you pass a file named "my_model.inc" to
the script is will write out a file in the same directory named
"my_model_wireframe.inc" that contains the macros
self-descriptive.

Because the exporter I'm using always writes the meshes the same way,
this script will only make wires for triangles that were defined like:
//-----------
#declare mesh_0 = mesh{
smooth_triangle{
<2.858558, 18.455250, 11.117654> <-0.000000, 0.257028, -0.966404>,
<0.002201, 18.455250, 11.117655> <0.000001, 0.257028, -0.966404>,
<2.858560, 35.636593, 15.687251> <0.000000, 0.257028, -0.966404>
uv_vectors <0.830126, 0.804765>, <0.884714, 0.804765>, <0.830126, 0.499519>
}
smooth_triangle{
<0.002201, 18.455250, 11.117655> <0.000001, 0.257028, -0.966404>,
<0.002203, 35.636593, 15.687252> <0.000001, 0.257028, -0.966404>,
<2.858560, 35.636593, 15.687251> <0.000000, 0.257028, -0.966404>
uv_vectors <0.884714, 0.804765>, <0.884714, 0.499519>, <0.830126, 0.499519>
}
//--------------
etc.
It picks out the three vertex/normal definition lines (ignoring anything
on either side of them like indents, commas, or comments), and after
finding three such lines it treats that like a triangle. This is a
fairly dumb script that only looks for those lines and can't handle
other shapes or anything, but works perfectly for well-formed files like
you get from an exporter.
The matching is done with a simple perl-style regular expression which
should be easy to change if your exporter works slightly differently, as
is it currently needs each value to have 6 decimals for it to be recognized.

To deal with shared edges it assumes that the triangles are sanely
defined (in that they are defined counter-clockwise around the normal,
facing out). This means that each edge could be defined twice but each
time would be in the opposite direction, so this checks for the reverse
direction of each edge before adding it to the grid.

I've been using it on my windows box in the command line as "@>php
C:\path\to\make_wireframe.php E:\path\to\my_model.inc", but included the
shebang and accounted for forward slashes in the filename so it should
work on a bash command line with simply "@>/path/to/make_wireframe.php
/path/to/my_model.inc"

An example image: http://cshake.homeip.net/disco/renders/Atka_wireframe.png
(the 'hidden' lines were made by using a semi-transparent solid-color
version of the original model inside the wires)

On the off-chance this is useful to someone, let me know if there are
any bugs that aren't due to the dumb way it finds triangles.

Chris


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