Senior Engineering Technician Wendi Burgin just started using AutoCAD Civil3D 2010, and she ran into a visibility issue with blocks that other users were sending her.
"I received several CAD files from others, and couldn't figure out why all of the blocks within the DWG files were missing or couldn't be seen in paper space. After much digging in the Autodesk Help file and on Autodesk discussion boards, I found the reason! The blocks are annotated and if you don't have the AnnoAllVisible system variable set to 1, you will not see the blocks in paper space, and they won't plot either (unless they are at the correct viewport scale).
"It's very frustrating if you don't know about this system variable! I have written this variable down on a Post-It note and stuck it to my monitor for future reference."
Notes from Cadalyst Tip Patrol: Often it is the things that are meant to help us that hurt us. AutoCAD 2008 (and its verticals) had a new Annotated Scaling feature added to it. This feature would make text, blocks, and dimensions visible at certain viewport scales. Add a scale to the annotated object and it would be displayed whenever viewed at that scale in a viewport. It also ensured that text (and the other objects) could be seen at any scale. This meant that you could label something in model space, make it annotated, and it would show up at the defined height no matter what the viewport scale.
The AnnoAllVisible setting will either hide or display annotative objects that do not support the current annotation scale. If it is set to zero, only objects that support the current annotation scale will be shown. If it is set to 1, then it will display all annotative objects.