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Revision as of 18:21, 4 January 2021 by MattEstela (talk | contribs)

Constraint Networks 3: A new hope.

I've been building my own constraint lines so far because it made it nice and clear in my head. Since 17.5 there's been a bunch of sops to help make these things for you. When they arrived I had a quick play, couldn't make them work, swore, didn't touch them again.

Well we're now at 18.5, I'm on a project that needs RBD again, seemed a good time to dive back in.

Multi outputs and modularity

The RBD constraint tools take ideas from Vellum. RBD sop nodes have 3 in/3 outs, first is geometry, second is constraint geo, third is guides. The other idea is to have RBD sops which can be chained together, so one sop might setup RBD object attributes, another creates constraint lines between them, a third modifies rbd contraint attributes, and this all gets wired to a RBD Sop Solver.

My initial frustration stemmed from not really understanding Vellum at the time, much less ported Vellum concepts to RBD, hence confusion and fury.


If you remember from the previous section the way to pin an rbd object was to:

  • Duplicate the point
  • Create a line between those points
  • Give the line prim a @constraint_name
  • Set one end of the points to have @name = ""
  • Create a constraint network in dops

Quite a lot of work, lots of places to make mistakes. Here's how you do it with the new workflow:

Rbd pin setup.gif

Yep, a single checkbox.