★★★ Why do graphics disappear or turn into small bright spots after double-clicking the middle mouse button in ZWCAD?

Issue:

During the drawing process in ZWCAD, after double-clicking the middle mouse button, the drawing disappears or appears as a small bright spot on the edge of the drawing area. the graphics cannot be seen no matter how you zoom in or out. How to make the graphics display again in this situation?

Causes:

This issue is usually related to drawings, there are extra graphics far away from the main subject in the drawing. After double-clicking the middle mouse button to zoom out the entire drawing, the main subject will become very small, appearing as a tiny bright spot or disappearing completely.

When facing this kind of drawing, select no objects and check the view size in the Properties panel (CTRL+1), as shown below. When the view size reaches an exponential level, zooming in or out using the scroll wheel will have little effect. Even if a tiny bright spot can be seen, it is difficult to adjust the graphic view to its normal state with multiple continuous zooming operations.

Solution:

1. If all the graphics disappear after double-clicking the middle mouse button, immediately use undo(Ctrl+Z) to restore the normal view. If you can no longer return to the normal view through undo, you can use center zoom. The specific steps are as follows:
   1. Input the command ZOOM and press enter;
   2. Then enter C and press enter;
   3. It prompts to specify the center point, input 0,0, which is the origin of the coordinate system as the center;
   4. It prompts you to input scale or height, you can set the height to 10000. If the drawing is very large, you can enter 100000 or a larger number;
   5. Some graphics may be far from the origin of the coordinate system, in this case, the graphic may still not be visible. You can continue to zoom out or pan the view to find the graphic.
      
2. After seeing a small part of the graphic, zoom in using the scroll wheel until all the graphics needed are displayed.
3. Press CTRL+A to select all the graphics, hold down the SHIFT key and select the graphics that you want to keep, filtering out all the unnecessary graphics. Press the DELETE key to delete the unnecessary graphics. Double-clicking the middle mouse button at this moment will no longer change the view size.
4. Alternatively, after step 2, select the graphics that want to be kept from left to right, then copy and paste them into a new drawing to exclude the unnecessary parts in the original drawing that affect the full-view display.