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Re: A basic question


Hi Abishek,
> I have just looked through YADE, and it looks to be a very powerful
> tool. However, before "taking the plunge", I would like to ask a few
> questions (I agreee they might look a bit silly :-) ):
> (1) I noticed that examples folder of the yade-0.20.0 download has a
> few .stl files. I would like to know if the code handles sphere to
> triangle collisions?...or is any arbitrary body "packed" with sphere?
Yes, we call triangles facets and you can use them to create arbitrary
(triangulated) surfaces: http://www.youtube.com/watch?v=PZVruIlUX1A .
Spheres can interact with spheres and facets, facets don't interact
between themselves (they could in principle, but it just wasn't

> (2) Is it possible to give prescribed motion to any body, especially
> an arbitrary shaped body imported from an STL file?
Yes, there are "engines" that apply linear motion, rotation, spiral
motion, linear motion with velocity interpolated from piecewise-linear
function etc, and you are free to write your own, which is quite easy.

If you want to apply such engine on a STL file, you pass facets' ids
(globally unique numbers) to the engine so that it knows which bodies to
> (3) Is it possible to run YADE on a parallel cluster?.and if can be
> run independent of the GUI? (that is..I make an input file, run in a
> parallel machine and postprocess in another machine?
Yes, yade supports parallel computation, but only with shared memory
(openMP), not networked cluster with distributed memory. That means you
can run about 4-8 computation threads practically (you can run more of
course, but you might get no additional speedup, depending on your

Simulations are typically prepared as python script, and you can run it
headless. For postprocessing, you can use VTKRecorder (engine inside
yade) + Paraview, gnuplot (yade.plot module) or write your own output
routine in python or c++ (easy).

HTH, Vaclav

PS. Have a look at scripts/test, that contains bunch of small
simulations, typically for testing purposes. That way, you can get the
feeling on how it works. The of course read documentation at
https://www.yade-dem.org/sphinx/ (not complete yet, sorry)