Clipped PDF Underlay, Existing in Model Space, Unintentionally Plots in a Polygonal Viewport in a Layout

[stgole]

I'm running AutoCAD Map 3D 2020. This took me hours to "solve" after having spent time fruitlessly looking for any previous solution.

A PDF underlay is located in model space. It's rectangularly clipped to show only the area of interest. My layout contains a polygonal viewport (6-sided) that shows "another area" of model space. This "other area" of model space and the rectangularly clipped PDF underlay don't intersect in model space. Despite this, the polygonal viewport in my layout ignores the fact that the PDF underlay is clipped and allows the PDF underlay to plot. To be clear, when the PDF underlay isn't clipped, it DOES intersect that "other area" of model space. Again, when the PDF underlay is rectangularly clipped so that there's no intersection with the "other area", my polygonal viewport in my layout ignores the fact that the PDF underlay is rectangularly clipped and the PDF underlay plots in the polygonal viewport.

My solution to this problem is to delete the polygonality of the viewport in my layout. This results in a rectangular viewport. The layout plots as expected after this. It's as if viewport non-rectangular polygonality causes this problem. Of course, it could be a more fundamental issue that causes the problem.

[ChicagoLooper · Accepted solution]

If you don't want to display your PDF in the polygon shaped viewport you can do this:

1. Put your PDF on a new dedicated layer. Name it PDF. No other entities should reside on this newly created layer. 
2. Go to your layout tab. Activate the polygon VP so your cursor appears 'inside' the viewport.
3. With the VP still activated, go to Layer Properties Manager and click the icon under the column named VP Freeze. See image below.

With the VP activated, click the icon for layer named 'PDF' under the VP Freeze column.

This procedure will freeze the objects on the 'PDF layer' displayed inside the polygon viewport. The freeze will only affect the 'activated' VP or polygon viewport. No other VPs will conform to this frozen layer state so the object, your inserted PDF, will be displayed in all other viewports. 

[stgole]

Thanks so much for adding to this discussion. We now have 2 solutions to this problem. I still wonder why my polygonal (6-sided) viewport doesn't accept the fact that my PDF in model space is clipped, but a rectangular viewport DOES recognize the clipped PDF. It might be a programmatic issue that's too difficult or resource-hogging to overcome.

[Netelaana]

Just ran into the same issue. Took me forever to figure out why I was getting ghost linework in my plots. Because the PDF underlay was clipped, it does not show up in the viewport or in modelspace, but the clipped portions would show up when I printed to pdf. I had to freeze the layer even though the pdf underlay was outside of the extents of the viewport. Very odd.

[stgole]

Thanks for the confirmation. Appreciated.