Re: [ESPResSo-users] constraint, i.e, shrinking cylinder

[Axel Arnold]

Hi!

Am 09.06.2015 um 00:13 schrieb Savan Kharel <address@hidden>:

1. I would like the put the particles inside a cylinder which shrinks in the middle (but still looks like a cylinder). I know that espresso has the constraint that is cylinder but its not clear to me how I can modify the cylinder.

The constraints are defined in 5 places:

./src/core/constraint.cpp

./src/core/constraint.hpp

./src/tcl/constraint_tcl.cpp

./src/tcl/constraint_tcl.hpp

./src/core/interaction_data.hpp

They are described by magic constants in interaction_data.hpp, and by gripping for CONSTRAINT_CYL, you can find the code implementing the cylinder constraint. Mostly, the constraints are defined by a distance function, and for any other than the shapes that are predefined, you will need to write a new one. Just follow the CONSTRAINT_CYLs...

Best,

Axel

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Axel Arnold
Martha-Schmidtmann-Str. 7
70374 Stuttgart, Germany
Email: address@hidden
Phone: +49 173 870 6659