About Working with Imported Faceted Geometry
The tessellated files that are imported from STL, VRML, STEP, and MEDUSA contain faceted geometry.
You can use the imported faceted data to:
Calculate mass properties and measurements such as distance, length, angle, and area.
Create datum features by referencing the faces, edges, and vertices of the faceted data.
You can select and reference imported faceted geometric entities just as you select and reference regular or exact geometry to create or redefine datum features such as points, planes, and axes.
The geometry is static and is an imported feature. Faceted geometric entities do not have permanent entity IDs as exact geometric entities. Referencing faceted data does not create parent-child relationships in the way that referencing exact geometry does. The datum features remain at the same absolute location or orientation in the part they are created even if the faceted data is modified or moved.
There is no association between the faceted data and the datum features created by referencing the faceted data.
The datum features are frozen in the model space of the parent model. Therefore, for an assembly with faceted component models, to update the datums with the faceted component location, create the datums in the context of the faceted component model. That is, activate the component and create the datum. The datums do not update to changes in the faceted geometry, but they update to changes in the component model location.