The fold angles & assembly positions(including the actual connecting of mates) and view angles in the 3D design, even though the user is asked to save fold angles when the 3D is closed.
In 16.1, the actual act of connecting of mates is considered assembly information and is not saved to the 2D unless the Update 2D button is clicked or fold angles are saved to the corresponding 2D.
The location of a mate is automatically saved to the corresponding 2D.
Board (material) properties:
ARD: With multiple contours as parts. The material properties can be pushed back to the 2D, but only if all the 3D parts have changed materials. The requirement is necessary since the ARD has only one material for all the parts in the ARD.
ACD: The material properties for any and all parts can be pushed back to the 2D.
Board Structural Properties
Care should be taken when making board changes. An ArtiosCAD board contains the finishing appearance and structural information in one entity. While in 3D, a user may primarily be focused on the boards appearance. However, the full definition of the board including structural allowances like CAL, IL and OG are also sent back.
For a resizable ARD that is rebuilt, the design structure may then change. As of this writing for a resizable ACD, the structural allowances of a board for a part are ignored, but that limitation is expected to change in the future.
As of 16.0.1, The number of duplicates of parts made in 3D can be pushed to the associated canvas file as its part count. However, if a design is added to a 3D scene via File > Add a Design, the design is not added to the associated canvas as a part. It is only for the 3D scene.
Hardware and mates
As of 16, hardware hooks can be added to a 3D design.
As of 16.1, 3D assembly mates can be added to a 3D design.
Hardware holes and mates as well as 3D assembly mate locations are immediately updated in the associated 2D design without user intervention when created or deleted in 3D. This is due to the fact that these elements are structural in nature. A user could switch back to the 2D and modify the design. If the 3D structural information is not immediately applied, the 3D information loses its relevance. The user may change the 2D design such that the 3D information no longer knows where it needs to go.
The other items described above are more related to the 3D scene. A user, at his discretion, may choose to update the 2D if he determines the 3D scene changes are relevant for the structural data.
The actual act of connecting mates is considered assembly information and is not saved to the 2D unless the user either Updates 2D or saved the fold information.
As of 16.1, hardware can be moved away from its panel in 3D via the Select & Move tools. In this case, the hardware is disconnected from the panel, meaning it will not mate when the 2D is converted to 3D in the future, but its holes are left. The user has to click the Update 2D tool to have this data pushed to the 2D design. This is a case where such an operation is considered more of a scene change.