UDM compared to User Defined Primitives
User Defined Models (UDM) resemble User Defined Primitives (UDP):

- Ansys EM products can be extended by users through new UDMs
- UDM plugins are discovered by searching standard directory paths
- Plugins for static UDM can build model using 'callback interfaces' (like create-box, create-cylinder, subtract etc) similar to UDP.
- UDMs run inside Ansys EM applications
- UDMs provide geometry, topology, persistence and parameters
In contrast to UDP:
- UDM provides multiple Parts/CS/etc.
UDP provides primitive operation only for a single Part
- UDM provides part attributes and material assignment
UDP does not define part attributes or material
UDM Properties have four tabs - Definitions, Parameters, Options and Info
- Definition tab has:
- UDM name
- Coordinate system used to position UDM
- May have external reference to file
- Info tab has:
- UDM dll or .py name, dll or .py location, version etc
- Option tab:
- may have options if any