The following workflow is general. The macros to use can vary.

Click Advanced Plate System on the vertical toolbar.
The Advanced Plate System ribbon displays.

Select Construction from the Macro Definition list.
OR
If Construction was selected earlier in the same session, and is visible in the Macro Definition list, click Plate Definition by 3D .
The Geometric Construction Palette dialog box, Geometric Construction Explorer dialog box, and Geometric Construction ribbon display.

If required, select a point geometric construction interface.

Follow the system prompts and create the points.

Click Continue.
The Geometric Construction Explorer shows a list of points.

Select a curve geometric construction interface.

Follow the system prompts and select points to create the needed curves. Select the points from the graphic view, the Workspace Explorer, or the Geometric Construction Explorer.

Click Continue.
A list of curves is added to the Geometric Construction Explorer.

Select a surface geometric construction interface.

Follow the system prompts and select curves to create a surface. Select the curves from the graphic view, the Workspace Explorer, or the Geometric Construction Explorer.

Click Continue.
A surface is added to the Geometric Construction Explorer.

Click Close.
The ribbon display returns to the Advanced Plate System ribbon.

Create boundaries for the plate system as required. Boundaries create connections between plates.

Click Finish.
The software creates a plate system using the geometric construction surface.