Is a mesh requried?

[josemendez]

However, I am curious as to why it was not until I had added the ConstraintUser interfaces to my custom actor before the constraint defined in the blueprint generator started working?
EDIT: I am asking this because I could not find any reference as to where these interfaces are used other than some Merge method.

Hi!

The Merge method you discovered has a very important role: when an actor is added to the solver, its constraints must be merged with the constraints of other actors in the solver for efficient data layout and parallelization, this is done on a per-batch fashion (see: http://obi.virtualmethodstudio.com/manua...aints.html). These "merged" batches used by the solver may contain constraints belonging to different actors, which allows it to work simultaneously on constraints of multiple different softbodies to maximize performance.

Batches of different constraint types in the solver will ask the actor for their constraint data, by checking if they implement the corresponding IWhateverConstraintsUser interface. If an actor does not implement this, the solver will assume the actor doesn't contain constraints of that type and they won't be considered by the solver during simulation.

Furthermore, assume I have a long Obi rod and I want to vary the stretch compliance accross the particles of the rod; then I can use the index parameter defined in IStretchShearConstraintsUser.GetStretchShearCompliance to return the appropriate complience value depending on that index param?

Yes, that should work.

kind regards,