Multiple nParticles?

[Anonymous]

Hii,

   I need to make a molecular simulation, hence I made few nParticles (and named them like carbon, oxygen etc.). Now hydrogen and oxygen should have some attracive force but they should not interfere with carbon. When I switched on Force field generation for oxygen and hydrogen, they also attracted carbon.

In symple my problem is- in three nparticle system with one nucleus solver, how can I generate force field for only two system which should not interfere with the third nParticle system. Also all of them should also have collision, hence I cannot use two nucleus solvers.

Thanks.

[rellwood]

You can use a Maya Field rather than using the nParticle Force Field attributes to attract the two particle systems.

To do this:

1. Select the two nParticle objects you want to be attracted to each other, and select Field/Solvers > Newton.

An easy way to connect and disconnect Maya Fields is to use the Dynamic Relationship Editor (Windows > Relationship Editors > Dynamic Relationship Editor). http://help.autodesk.com/cloudhelp/2016/ENU/Maya/files/GUID-D1DBBFC8-EFF0-4DA6-B285-369848CBBFC5.htm

2. To allow the Newton field to act on the particles you must turn off the influence of the Nucleus Gravity. In the Dynamic Properties section of the nParticleShape nodes, turn on Ignore Solver Gravity. Otherwise, the gravity overpowers the Newton field.

You mentioned that these particles need to collide with each other, so I am assuming they need to be animated in some way. Try using the Nucleus Wind adding Nucleus Wind or  a Gravity Field to all three to get them moving.

[Anonymous]

Please refer to the attached figure. 

I have three nParticle system here i.e. carbon, oxygen and hydrogen. I have constraint them to form bonds.

Anyhow, only oxygen and hydrogen should have attractive force and every particle in them should contribute. The newton field creates at field at a particular location and hence attract all partiicles to a particular location. But I have to deal with every particle that comes under oxygen and hydrogen and they should have their own field.