A .vrscene file can be opened in Lavina in one of two ways:

FIle > Open Scene > Select the .vrscene;

or you can drag-n-drop the .vrscene file directly into Lavina and it automatically renders the scene.

https://drive.google.com/open?id=10XNFzLhMF2UcfpMuxPYGVcfyEHyt-CQo

When drag-n-dropping a .vrmesh or .vrscene file you get two options - to Merge the new asset with the currently opened scene or to Discard the currently open scene, while keeping the new asset.

This example shows adding a .vrmesh file into an already opened scene and assigning a material to it.

https://drive.google.com/open?id=1kXVVX-BHhEF0oBLTnCQCwBB_CRWWJ280

You can also drag-n-drop an environment file (.hdr map) or a configuration file (.vrdx). That action adds the new asset directly to the scene.

In this example two different .hdr maps are loaded as environment maps. Then, the settings are saved as two separate configuration files. By drag-n-dropping the configuration files directly into the scene, you can change the entire render.

https://drive.google.com/open?id=13FaHQrs2tuA2uuweupcaz1ZP542e8iR6