Have you ever tried to add a dimension to an Inventor IDW or DWG and wanted to have the snap options that are in ACAD? This is a frequently forgotten way to obtain the results you desire.
When adding a dimension to a drawing, if you find that you are not able to select the desired entities, right-click and select Snap Settings. If the option is checked, it will find that entity. If not, check the desired snap mode.
The snap mode will now make it easier to select your desired results.