Merging 3D layers allows you to combine multiple 3D models in one scene. Once combined, each 3D model can be manipulated separately, or you can use position and camera tools on all models simultaneously.
After merging two 3D models, all meshes and materials from each 3D file are contained in the target file and appear in the 3D panel. In the Meshes panel, you can select and reposition individual meshes using the 3D position tools in the panel. See 3D Mesh settings.
To alternate between moving all models at once and moving individual models in the layer, switch between the 3D position tools in the Tools panel and the tools in the Meshes panel.
You can combine 3D layers with one or more 2D layers to create composite effects. For example, you can place a model against a background image and change its position or viewing angle to match the background.
In a multi-layer document with 2D layers above a 3D layers, you can temporarily move the 3D layer to the top of the layer stack for faster screen rendering.
When you hold down the mouse button with either tool, all 2D layers are temporarily hidden. When you release the mouse, all 2D layers reappear. Moving any part of the 3D Axis also hides all 2D layers.
Converting a 3D layer to a 2D layer rasterizes the 3D content in its current state. Convert a 3D layer to a regular layer only if you no longer want to edit the 3D model position, render mode, textures, or lights. The rasterized image retains the appearance of the 3D scene, but in a flattened 2D format.
Converting a 3D layer to a Smart Object allows you to retain the 3D information contained in the 3D layer. After converting, you can apply transforms or other adjustments like Smart Filters to the Smart Object. You can reopen the Smart Object layer to edit the original 3D scene. Any transforms or adjustments applied to the Smart Object are then applied to the updated 3D content.