I received the following question from a partner: “Are there any plans to have a cut plane view in the viewer?”
To my pleasant surprise, this functionality is already there in the latest production version of A360 viewer. Since it was so fresh from the oven, I did not know about it. API has been there since last November. It's under Viewer3D.setCutPlanes(). This will be a very useful feature. Please try it out if you haven't, yet.
"Section Analysis" tool (middle-left along GUI tools) allows you to add a cut plane or "crop box" (in Revit wording) and to examine the section of 3D model. Top: the imagine on the top shows a model with a cut plane. Above: the original 3D model.
GUI tool set for cut plane.