
Michael J de Smith 




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VORTAL models Steiner
problem in the plane, with obstacles VORTAL procedure applied
to a triangular region optimisation problem (Steiner problem) with obstacles.
Sample topology shown
consists of three paths (coloured) and a single connecting point. VORTAL stands for
Variationally Optimised Rapidlyexpanding Random Trees (RRT) Algorithm. VORTAL
interactive program (steiner.exe) Gradient constrained problem in Pentland Hills region, Scotland (pentland.exe) In this example a path is
sought across the physical landscape which is of minimum length and satisfies
the gradient constraints
imposed (over the step length/path segments selected). In this case the
constraint is that no step can have a
gradient of greater than 10%. The red lines are the RRT search routes, the
black line is a feasible solution path
and the blue line, a shorter path that is based on the initial solution and
still satisfies the gradient constraints,
although its step length may imply a greater degree of cut and fill. The code for this program
and notes to be read first are provided below (updated 25 Oct 03): VORTAL
model with gradient constraints (pentland.zip) Notes
on pentland.zip
(pentland.txt)  read this first! Details of RRT can be
found at : http://msl.cs.uiuc.edu/rrt/ 



© 2002, 2003 Michael J de Smith 