Create 3D intersection
By default in Motion, the order of layers in the Layers list determines the stacking order of layers in the Canvas. In other words, layers higher up in the Layers list appear in the Canvas on top of layers that are lower in the Layers list. This hierarchy of layer organization is called layer order. Even when you move a layer forward in Z space using 3D transform handles, that layer does not pass through or move in front of layers that are higher in the Layers list. Layer order prevents intersection and interaction of layers.
Important: 3D text objects only intersect with other 3D text objects. Additionally, 3D text uses only layer order: For 3D text to appear above other non-3D text layers, the 3D text must be positioned above the other layers in the Layers list; the text’s Z position in the Canvas has no effect. For more information, see About 3D text intersection and layer order.
In the image below, groups Red A and Blue B are positioned at the same point in 3D space. But because they are layer-ordered, Red A does not intersect with Blue B.
To have objects intersect in the Canvas, you must convert groups in your project to depth order. You do this by converting 2D groups to 3D groups.
In the image below, because the parent group has been converted to 3D, groups Red A and Blue B now intersect.
Groups and layers nested in 2D groups are composited in layer order.
Groups and layers nested in 3D groups are composited in depth order.
A Motion project can contain both 2D and 3D groups, and both groups can be parents or nested children of one another. And you can convert a group from 2D to 3D, and vice versa, at any time.
Convert a group from 2D to 3D to enable intersection
In the Layers list, select a 2D group, then do one of the following:
Click the 2D icon to the right of the group in the Layers list.
Choose Object > 3D Group (or press Control-D).
In the Group Inspector, click the Type pop-up menu, then choose 3D.
The 2D group icon is replaced by a 3D group icon, and layers and groups nested in the parent group are converted to depth order, allowing intersection with other depth-ordered layers and groups. To change a group from 3D to 2D, use the same method described above.
Important: Some operations, as well as the application of some filters or a mask, cause a group to be rasterized. When a group is rasterized, it’s converted into a bitmap image. Rasterization affects 2D and 3D groups in different ways, sometimes preventing 3D intersection. For more information, see Groups and rasterization.