Particle Instancing

MTOR 3.0 introduces support for Maya's particle instancer.  For complete details on how to set up your scene for particle instancing, please refer to the Maya docs.  Below we present a brief sketch of the workflow but first, a caveat: the exact mathematics behind Maya's particle instancer are poorly documented.  There are some cases where we do not correctly translate Maya's configuration.  Generally, if you stick to the proscribed steps and avoid obscure orientation configurations, you should be fine.
To create a particle instancer:
  1. Setup one or more models for instancing.  To ensure that MTOR's instancing matches Maya's make sure that the top level node has no rotational transforms.  If you need to reorient your object, you should create a grouping node and perform orientations below that node.
  2. Create a particleShape node.  Usually you'll do this by simply creating a particle emitter but you can also create particles in other ways.
  3. Select the particleShape node and the objects you wish to instance.  Now invoke Maya's Instancer command (found in the Particles menu).  A new instancer node should now appear in your scene. The instancer node is responsible for describing the high level instancing behavior and maintaining connections between the particleShape nodes and the instanced objects.  At right, you can see the controls of the instancer node.   Here you can choose whether and how to cycle between multiple shapes used for instancing.  In our example, we're only instancing a single object - bugger.
  4. Next you should edit the instancer attributes associated with the particleShape node.  This is where you establish most of the options governing the position and orientation of each instance.  And it is here that some compatibility issues have yet to be resolved. If you limit your choices to specifying a subset of: RotationType, Rotation, AimDirection and AimPosition, you should get acceptable results.  Obscure interactions between AimAxis, AimUpAxis and AimWorldUp causes MTOR a slight case of dispepsia.



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