yade-users team mailing list archive

[Václav Šmilauer <eudoxos@xxxxxxxx>]

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
written).

> (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
manipulate.
> (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
simulation/hardware/...).

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)