topic Dimension in Annotation - From edge to an intersection of center line and diameter in Drafting

Dimension in Annotation - From edge to an intersection of center line and diameter

TH_12309063 — Mon, 16 Mar 2026 18:52:13 GMT

Creo Elements Direct Modeling 20.7.1.0 (English):

I can't "snap to" or "catch" an intersection when dimensioning.

In this case I would like to dimension from the bottom of a key slot to the top of the shaft at the 12 o'clock position. The only way i have found is to draw a very short vertical geometry line at the point where the center line intersects the diameter line. When I create this line I can snap/catch the intersection of the center line and the diameter line WHY can't I catch the same intersection when dimensioning?

Thank you for your help.

Tim Higdon

Re: Dimension in Annotation - From edge to an intersection of center line and diameter

Kotom-Eng — Tue, 17 Mar 2026 04:53:46 GMT

You cannot dimension catching an intersection because a dimension in Modeling is attached to a vertex (the point of the end of an element) or an element.

An intersection is virtual, ie not stored in the file of the drawing.

In your case, use the tangential dimensioning.

Re: Dimension in Annotation - From edge to an intersection of center line and diameter

TH_12309063 — Tue, 17 Mar 2026 14:53:16 GMT

Respectfully, I do not agree with this reply. However your reply does highlight the quandary "An intersection is virtual, ie not stored in the file of the drawing". If this is true then why was I able to create a geometry line (in annotation) by snap/catching this virtual intersection of the center line and the diameter line. The reply is not considering/addressing this very important point.

Again my question is why can't I catch the same intersection when dimensioning?

Thank you for your help.

Tim Higdon

Re: Dimension in Annotation - From edge to an intersection of center line and diameter

Kotom-Eng — Tue, 17 Mar 2026 17:12:03 GMT

When a line is created with the help of catching an intersection, new entities are created, a line and 2 points corresponding to the ends of the line. Once created, these three entities are no more connected to the intersection. The information that the line was created by catching an intersection is lost. This applies for the drafting in the computer memory and in the file.

When a dimension is created, its structure is stored in the computer memory and in the file with a pointer to the two measured elements and their reference points. Today, in the structure of the dimension, there is no way to store the informations for the intersection, which would implies to store the pointer of at least a third element. The reason why this is not implemented in Annotation should be asked to PTC.