The RBF Training View

The RBF (Radial Basis Function) Training View is a view in Aria that allows Maya transforms to be trained using a special RBF solver contained within the flexSolver node.

When creating characters there is a way to drive transform data from shape data by passing the transform data for each network node in a shape network through machine learning. A very practical example would be connecting eyelashes to the eyelids. In a real-time end medium like a run-time game engine these types of calculations can be expensive but leveraging the RBF training in Aria we can radically reduce computational time for evaluating transforms and their relationships to shapes. Another practical example would be a rivet on a piece of geometry. The issue with a rivet is that anytime the blend shape node updates the mesh the rivet needs to evaluate the mesh and then calculate its new position. What the RBF training does is uses machine learning to evaluate the transform's relationship to the surface for each shape and records it in the flexSolver thus decoupling the transform from the geometry and having no need for the rivet. This removes the computationally expensive step of evaluating the geometry each time a shape has a new value.

The setup for the RBF training is you add Maya transforms to the training session via the RBF Training View. Internally Aria will calculate a rivet matrix and UV data as each node is added to the training session. When you train the system the UV rest coordinates calculated when you first added the transform to the training session are evaluated for each shape in the network and produce a new transformation matrix for the trained node. This is then stored in the flexSolver for use.

Adding RBF Data Frames

Select the Maya nodes you want to add to the RBF training session the click the "Add" icon in the view.

Once you click the add RBF data frame button a dialog will appear to ask you which type of transformation data do you want the data frame to record. You can choose to train on translation only or translation and rotation. When the training session is over the channels of whichever transformation you choose will be connected to the output of the flexSolver node much like the transformation channels would be connected to the output of a rivet node.

The other option will be which UV set to use to capture the UV coordinates. When Maya nodes are first added the closes point on the neutral mesh from each transform is calculated and the rest UV coordinate is calculated. This UV coordinate will be used during training to inverse the calculation and tell the transform where it should be in space given each shapes weight value on the blend shape node.

Once you choose which output type a

Removing RBF Data Frames

Select any number of rows in the table and click the remove data frames button and the rows will be removed from the table and the RBF data frames removed from the solver.

Refreshing The UV Coordinate Data

If you are working on updated to a new neutral, a new character or the Maya nodes that are in the RBF data frames you can update the rest values by clicking on the refresh icon. Aria will recompute each data frame to generate the new UV coordinates.