When you are working on a Compo Composite 2D Layer, Shape layer and 3D Layer together. [Ctrl] + [Shift] + [N] to create a new composition after opening Smode Read More that contains 3D elements, you can choose to preview the 3D view of your objects in the Viewport Preview and edit your content Read More , allowing you to move around in the 3D space, or the 2D view from a specific viewpoint (choose this viewpoint by creating a Camera A camera filming 3D content Read More in your Compo, or selecting an existing camera as 'Current Camera').
To switch between the 2D and 3D view, click the button with a blue (2D) and a yellow (3D) square, on top of the Viewport Preview and edit your content Read More :