NAME
stripe - converts a .obj file to a .objf file.
(converts a polygonal model to triangle strips)

SYNOPSIS
stripe [options] [file.obj]

DESCRIPTION

The purpose of stripe is to speed up rendering time by converting a polygonal model to triangle strips. This manual describes the implementation of stripe, which was written by Francine Evans under the guidance of Steven Skiena and Amitabh Varshney, SUNY at Stony Brook.

Stripe's input is a .obj file in binary or ascii (default) and its output is a .objf file in ascii, which contains the model represented by triangle strips. You can then use the .objf file to render the model. We provide a viewer called viewobjf which uses opengl to render the model.

There are two phases to stripe: a global and local phase. In the first phase, the global phase, stripe finds patches of quadrilaterals and converts them to triangle strips, while also trying to extend off of the ends of the patches. stripe works especially well with models with quadrilaterals, since there will be many patches, and the patches form good sequential triangle strips. However, stripe does not only work with models containing quadrilaterals. It works on any model consisting of polygons.

The second phase, the local phase, uses a local algorithm to determine strips on the polygons that are left after the global phase cannot find any more suitable patches. This local algorithm uses adjacency information to determine which polygon to use next in a strip, and also triangulates the polygons on the fly to produce better strips.

The default options are the options that we observed to work the best. You can specify different options other than the ones that are set as the default, or simply leave off any options to use the ones that we found to be the best.

OPTIONS
-a
In case there is a tie as to choosing the next polygon in a strip during the local phase, this option will alternate left-right direction in choosing the next polygon in a strip during successive tie-breaks.
-b
This specifies that the input file is in binary.
-f
In case there is a tie as to choosing the next polygin in a strip during the local phase, this option will simply choose the first polygon that it found.
-g
This option specifies to find triangle strips only within the groups that are specified in the data file.
-l
In case there is a tie as to choosing the next polygon in a strip during the local phase, this option will look ahead to the next level: it will examine the neighbors of each of the polygon's that tied and choose the next polygon in the strip based on which one has the best neighbor to put in the strip at the next level.
-p
This option specifies that during the local phase we will be partially triangulating faces when we use them in a strip, saving the rest of the face for later and only using what we need for the current strip. This is the default option, if no triangulation option is specified.
-q
In case there is a tie as to choosing the next polygon in a strip during the local phase, this option will choose the next face that does not produce a swap (degenerate triangle). If this is not possible, then the lookahead method is used (option -l). This is the default option for tie breaking, if no tie breaking option is specified.
-r
In case there is a tie as to choosing the next polygon in a strip during the local phase, this option will randomly choose the next face from the list of tied faces.
-w
This option specifies that during the local phase we will be fully triangulating a face as we come to it in a strip, without saving any of it for another strip.

SEE ALSO
viewobjf(1)

BUGS
Stripe assumes models consisting of convex polygons.
Stripe assumes no more than 254 characters on a line.
Stripe assumes polygons of 3 sides or greater.
Please report any bugs to evans@cs.sunysb.edu

AUTHOR
This manual page contributed by Francine Evans of Stony Brook University. It has been reviewed by Steven Skiena and Amitabh Varshney of Stony Brook University.