[Bf-committers] New force type patch: Spring (Farsthary)

[Raul Fernandez Hernandez]

Hi all :)

Searching to add spring forces for the fluid particles I end up with a
nice patch that adds also spring force as a new general force type that
could be used like any other blender force: for objects, particles, etc.
Needless to say the importance and wide use cases for spring forces in 3D,
previously this functionality was aviable in Blender only in
softbodies,cloth and constraints but with this patch could be extended to
particle systems for many SFX's and also to objects, te posibilities are
endless :)
 Is interesting to note how the particle system integrate features from
softbodies and fluids :)

 I will send thi spatch also to Jahka for review and commit

 Is very easy to implement and does not break any previous code, it only
will need a new UI slider for spring rest length but I'm not good at UI
coding, though it should be easy to add :)

   http://www.pasteall.org/9806/diff

                                                          Hope you like
it,  cheers  
Farsthary :)