Refresh and Auto Refresh
Keep the active background map synchronized with the current drawing view.
Overview
After a background map is loaded, the current CAD view can change. Use Refresh to manually request a new image for the current view, or enable Auto refresh on pan / zoom to let SPCAD refresh when needed.
Manual Refresh
- Pan or zoom to the area that should be covered by the background map.
- Click the Refresh button in the Background Maps toolbar.
- SPCAD requests a new map image for the current view.
- The existing raster image is updated or recreated, then the drawing is regenerated.
After a successful manual refresh, SPCAD writes a status message with the zoom level, tile count, cached tile count, and downloaded tile count.
Auto Refresh on Pan / Zoom
When Auto Refresh is enabled, SPCAD listens for view changes. It refreshes the map when the current view moves outside the existing buffered map coverage or when the user zooms in enough that the existing image no longer has enough detail.
| Situation | SPCAD Behavior |
|---|---|
| View is still inside the buffered raster | SPCAD usually skips the refresh to avoid unnecessary requests. |
| View moves outside the buffered raster | SPCAD requests a new background map image. |
| User zooms in significantly | SPCAD refreshes so a higher level of detail can be used. |
| Auto Refresh is off | SPCAD does not refresh automatically. Use the Refresh button manually. |
When Refresh Is Skipped
SPCAD may skip a refresh if the current view is too large for a single warped basemap image. This is most common when zoomed very far out in projected drawings.
Session Option Storage
The Auto Refresh switch state is stored with the active background map session. When the palette refreshes, it reads the active session and updates the switch to match the stored value.
If no active session exists, the switch cannot update an existing map until you load one.