Circle displayed as polygon
CAD system has optimized the display of circle, if you find a little circle in the current viewport becomes sort of polygonal after zooming out for many times, just enter RE and press Enter key to regenerate the displaying data to make it appear normal.
However, if you’ve set the Arc and circle smoothness value very low such as 9, then you are very like to get a circle displayed as a polygon, and RE cannot make it appear like a normal circle. The Arc and circle smoothness can be found as below,
Fill not displayed
If your fill objects in the drawing cannot be displayed as usual, please check if you have turn off the FILL mode by entering FILL in the command line, this command is used to control the display of filled objects such as hatches, 2D solids, and wide polylines.
Turn on the Fill mode and then enter RE and press Enter key to get the fill back.
Contents in viewport not displayed
Some viewports in the layout are displayed as blank, one reason is you have chosen “No” for the Display Viewport Objects option, shown as below,
Another reason is that there are too many viewports and exceeds the limits.
Objects displayed in model space but not in layout
Since we can freeze different layers in different viewports in the layout, it is possible that we what’s in the model space is different from what’s in the layout space and that different viewports in the layout have different displaying effect, so just check your layer settings.
Objects only displays after being selected
It is rare that the objects only display after being selected, but when it does, most of time it’s because some WIPEOUT has been placed in the wrong place and block the other objects, just place the wipeout under the selected objects.