In my previous Annotation Scaling posts, I mentioned scale representations but I didn’t tell you what they are. The time has come!
Think about how you work in AutoCAD today, prior to having the new annotation scaling tools. If you want to display the same geometry in different viewports at different scales, you need to create the annotations at different sizes. For example, the following image shows two details of the same geometry. The one on the left is scaled at 1:8 and the one on the right is scaled at 1:4. If you want the text height of all the dimensions to be 1/8” on the layout, you will need to create the annotations for each of the viewports using at different sizes. The modelspace text height for the annotations in the left viewport is 1” and the text height for the annotations in the right viewport is ½”. If you want an annotation to appear in both viewports, you must create two versions, one for each scale. The problem is that you must carefully manage those multiple copies of the annotation. You would probably control their visibility in each viewport using layers. And, if you want to change the text, you would have to edit it twice; once for each object.
In AutoCAD 2008, scale representations emulate how you currently address this need. However, they do it with a single object. For example, using annotation scaling, the TUBE leader is one object with two scale representations. If you want to change the text, you only edit it once. Also, you don’t have to calculate the modelspace text height. To create scale representations for an annotative object, you simply apply the proper paperspace size (1/8” in this example) and the scales you want it to support (1:8 and 1:4). You don’t have to apply crazy sizes by calculating scale factors. The added benefit is that the viewport scales can control the visibility of the annotative objects. For example, the TUBE leader supports both 1:8 and 1:4 scales so it is displayed in both viewports. The PAVING leader, on the other hand, only supports the 1:8 scale so it is only displayed in the left viewport. The HEAVY DUTY LOCK leader only supports the 1:4 scale so it is only displayed in the right viewport.
For now, keep this information about object scale representations in the back of your mind. In my next Annotation Scaling post, I’ll discuss Annotation Scale and then I’ll describe how Annotation Scale and object scale representations work together.