Pi Day Update

Happy Pi Day!

Last week I emailed our previous lab director Joe for advice on the tool implementation, as I had some questions about the Maya API as well as uncertainties on how best to approach it. I'll summarize some takeaways here:

The authoring tool will most likely be a collection of nodes and commands, where each node represents a modular portion of the overall task. This piece of advice was really helpful, since I originally envisioned the tool to be one monolithic node. He also clarified that nodes add pieces to the underlying Maya engine in the dependency graph, while commands make new features available to the command engine (namely calling nodes and issuing updates right away), so the tool will most likely require a combination of both. Previously I had thought nodes and commands were an either-or case, which it clearly is not.

I also asked about the viability of storing an overall state for a collection of nodes (for my river node network), and was told that while it could be done, the general paradigm in Maya is to propagate information down. Taking that into consideration, I'm currently working on creating a new RiverNetwork Maya Node. It will take in as input a CV curve as the river contour, and output an array of position values for the generated set of river nodes. These can be visualized with a simple sphere connected to an instancer.

One thing I'm still not sure how to handle is how to represent the parent-child relation between the generated output (this information will be needed to visualize the river graph part). To my [limited] knowledge, Maya nodes can only output objects that are MFnData, and it might take some extra work to figure out how to make one of the following data types work:

kInvalid Invalid value.
kNumeric Numeric, use MFnNumericData extract the node data.
kPlugin Plugin Blind Data, use MFnPluginData to extract the node data.
kPluginGeometry Plugin Geometry, use MFnGeometryData to extract the node data.
kString String, use MFnStringData to extract the node data.
kMatrix Matrix, use MFnMatrixData to extract the node data.
kStringArray String Array, use MFnStringArrayData to extract the node data.
kDoubleArray Double Array, use MFnDoubleArrayData to extract the node data.
kIntArray Int Array, use MFnIntArrayData to extract the node data.
kPointArray Point Array, use MFnPointArrayData to extract the node data.
kVectorArray Vector Array, use MFnVectorArrayData to extract the node data.
kComponentList Component List, use MFnComponentListData to extract the node data.
kMesh Mesh, use MFnMeshData to extract the node data.
kLattice Lattice, use MFnLatticeData to extract the node data.
kNurbsCurve Nurbs Curve, use MFnNurbsCurveData to extract the node data.
kNurbsSurface Nurbs Surface, use MFnNurbsSurfaceData to extract the node data.
kSphere Sphere, use MFnSphereData to extract the node data.
kDynArrayAttrs ArrayAttrs, use MFnArrayAttrsData to extract the node data.
kDynSweptGeometry SweptGeometry, use MFnDynSweptGeometryData to extract the node data. This data node is in OpenMayaFX which must be linked to.
kSubdSurface Subdivision Surface, use MFnSubdData to extract the node data.
kNObject nObject data, use MFnNObjectData to extract node data
kLast Last value. It does not represent real data, but can be used to loop on all possible types