Think of each unique Scene file as a unique level. Think about what you want to export: some scene A Scene contains the environments and menus of your game. Alternatively, you can export an FBX file from Cinema4D instead. Offers a wide variety of assets, from textures, models and animations to whole Project examples, tutorials and Editor extensions. To continue using Cinema4D files in Unity for versions 2019.3 and later, install Maxon’s Cinema4D importer from the Asset Store A growing library of free and commercial assets created by Unity and members of the community. Note: As of Unity 2019.3, Unity no longer provides built-in support for Cinema4D files. In addition to these generation guidelines about exporting from 3d modeling applications, the following sections contain more specific information for these 3d modeling applications:

Verify and import the FBX file into Unity.Check the FBX settings before exporting.Prepare what you need to include inside your 3D modeling application.Select what you want to export inside your 3D modeling application.Use these guidelines to help ensure the best results: Unity supports FBX files which you can export from many 3D modeling applications. For more information about importing these file formats, see the SketchUp Settings and SpeedTree topics. However, there are two file formats that do not use FBX as an intermediary: SketchUp and SpeedTree. Note: This section provides information about proprietary file formats that use FBX conversion.

Unity export scene to fbx