There are a number of data types in MLDesigner that are NOT recommended to be used by external developers because they are either insufficiently mature or most likely to be changed in the future.
Submatrices
The MLDesigner kernel contains a set of matrices to support efficient computation with submatrices. These classes were developed specifically for the experimental multidimensional SDF (MDSDF) domain and will probably be implemented differently in a future release.
Image Particles
A set of experimental image data types, designed to make it convenient to manipulate images and video sequences in MLDesigner, were defined by Paul Haskell. They are based on MLDesigner’s built-in Message type.