Why there are blank viewports on the CAD layout?

Sometimes when we open a drawing and enter the layout, we can see some viewports are normally displayed while others are blank, why? The following are the reason.

“Display Viewport Objects” is “NO”

If the “Display Viewport Objects” is “NO”, the viewport will be blank. So when you get blank viewport, you should check this option first.

After selecting the viewport, right click to check and set the “Display ViewPort Objects” in the right-click menu, as shown in the following picture.

If there are many viewports in the layout and the drawings are complex, we can improve our operating speed by setting “ Display Viewport Objects” to “NO” for those viewports that we currently don’t need.

Normally, we don’t need to change the default of this option, but if it is set to “NO”, we may take a look at the plugins that you are using or look into the function setting of your professional software.

The viewport number has reached limit

There is a limit of how many viewports can be activated in the CAD layout. If the limit has been reached, the viewports would appear as blank.

I recommend one drawing border on one layout, but too many times I see multiple drawing borders on one layout in paper space just like in the model space —- one layout is stuffed with multiple drawing frames and a large number of viewports are created. This kind of drawings are slow to switch between layouts and sometimes have blank viewports.

At most how many viewports we can have in layout space is determined by the variable MAXACTVP (Maximum Active Viewports) and the maximum is 64, but sometimes we can still get blank viewports even if the viewports are not so many, that’s because the MAXACTVP has been customized to a smaller value such as 8.

Solutions:

If the MAXACTVP value has been modified and is less than 64, we can change to value to 64.

If there are more than 63 viewports in the layout and those viewports can be displayed normally, what should we do?

Those viewports are not in the same drawing frame, the solution is to split the layout to make the viewports in a single layout have fewer viewport than the MAXACTVP.

Does this mean that I have to create a layout and create all those viewports?

No need! I have found a better way to do this —- to copy layout.

The detailed procedures are as follows:

1. Right click the layout tab in the layout space, select “Move or Copy”, as shown in the following picture.

2. Select the layouts that you want to copy in the popped up dialog box, check the “Create a copy” at the bottom of the dialog box, as shown in the following picture.

3. Click “OK” button to copy the layout.

4. Enter the original layout, window select and delete half of the drawing frames, and then switch to the copied new layout, delete the drawing frames in the original layout. This way, one layout is divided into two with no more than 64 viewports in both of the layouts and every viewport can be normally displayed.

There is another reason that may also be the cause of blank viewports: the viewport scale is too big or the displaying part is the blank space of the drawing, in such cases, we can enter the viewport and double click with the middle button of the mouse to view entire drawing, and then reset the viewport scale and orientation.

Conclusion: When viewport appears blank, select the viewport first and right click to check the setting of the display objects and go back to layout to find how many viewports are out there, if there is no problem with all those settings, then check the scale of the viewport and the views. If they are not the problem, then we will have to solve the problem on a case-by-case basic.