Isometric viewport not in true scale

Issue

You have set up a viewport in paper space that has an isometric view of your model. However, when you measured a distance along the X or Y axis of the model, the length was not correct.

Solution

In AutoCAD®, isometric viewports are displayed as isometric projections.

An isometric projection rotates the objects in an isometric view, and then projects the corners perpendicular to a plane of projection as seen from an infinite distance.

To display the isometric viewport as an isometric drawing, you need to change the viewport scale by a factor of 1.22474487. Follow these steps:

1. Switch to the Layout that contains the isometric viewport.
2. Select the isometric viewport.
3. In the Viewports toolbar, place your cursor in the Scale drop-down list.
4. Enter the new scale value. For example, if you want to display the isometric viewport in a 1:1 scale, enter 1.22474487:1. For a 1:20 scale, enter 1.22474487:20.

Note: In order to accurately scale the viewport, you need to use a standard isometric view from the view list.

See also

Variable viewport scale in paper space