Auto-Scrolling When Dragging
You can set a preference on the General tab of the Preferences dialog box to control auto-scrolling.
When this preference is checked, Image Authoring scrolls when you drag the cursor outside the current view so that you can see the effects of your mouse movement. This applies to operations with vector-based tools, such as the Trace tool on the Mask page and the Add Feature tool on the Sketch page. It does not affect the 3D Modeling page.