Question: How do I place the origin or “corner” for the Ordinate Dimension?

The approach that Rhino takes is to create these ordinate dimensions in the active detail or on the model.

• The ordinate dimension uses the current cplane.
• You can set the cplane origin to the corner of the geometry that you will be dimensioning to.
• To make a construction plane, use the Cplane command with the 3PT option or other preferred options.
• Use NamesCplanes to save your cplane and restore the cplance for additional dimensions or editing.

• The layout arranges details that contain views of your objects and ordinate dimensions.
• If you need to edit the location of the geometry, make the cplane active before moving the geometry.

See video here.

Download sample (Rhino 7) file here.