A custom Maya node that can be found here:
https://github.com/parzival-roethlein/prmaya
A few months ago I started making improved array versions of Maya nodes for smaller, scalable, procedural graphs.
The prKeepOut node specifically had some relevance for production: I had an asset with around a hundred armor pieces and I thought about using keepOut nodes, but ended up deciding against them because it would have been overkill: Each armor piece would have required multiple keepOut nodes, which would have slowed down the rig a lot, take a long time to setup and probably never really work that well, because of multiple armor pieces overlapping in areas with multiple deformation axes. In the end I copied the skinCluster and blendShapes from the body and tweaked them to make the armor deform more rigid and add some offset controls for a few of the armor pieces.
It took me a few evenings after work to write prKeepOut, so in hindsight I wondered why I hadn't done it sooner. The "algorithm" is less than 100 lines and the rest is just the verbose Maya API way of creating/querying/setting attributes.
I thought about writing more about the making-of and reasoning. But it's open source and just basic Maya API, linear algebra usage. And I imagine the changes make sense to anyone who has used the 10 year old Maya keepOut node.
Initially I had shape inputs specific for each ray to support multi layer collision, but removed it again, because it would make the node usage too complex and risk evaluation cycles.
With the recent input matrix announcement for transforms in Maya 2020+ I'm thinking about switching to matrix outputs.
A few weeks later Autodesk announced bifrost graph, which looks amazing and will hopefully make these kind of custom nodes obsolete.
