Flattened PDF

Is there any way to create a flattened PDF where everything is on the same layer?

My ultiimate goal is to be back to create a base model (2d) and be able to annotate it in Rhino at different resolutions and detail. A high resolution base model will have more annotations than an low resultion.

The base base models have a large number of layers. I don’t want to wade through all those layers in the annotation phase.

Make2D, select objects on (resulting new) layer Make2D/Visible, print selected to pdf

First off, saving/exporting as a raster file puts everything on one layer.

Second, if you have to save/export as a vector file, you can open the pdf in Adobe Acrobat and open the Layers tool, click on the three dots to open a menu and choose the Flatten Layers option:

You will be warned that this process is irreversible. Assuming you go ahead, your PDF will be reduced to a single layer.

HTH
Jeremy