The clouds in the above screenshot are rendered with a skybox layer.
With the skybox layer you can render 360° backgrounds.
Choose LAYER > Add layer > Add skybox layer... to create a new skybox layer.
The new skybox layer can be selected from the layers dropdown to make it the active layer.
The installer comes with shows demonstrating the possibilities of the skybox layer. Choose FILE > Open show... and select a show from the BluffTitler/Media/Shows/Skybox folder.
To quickly switch between your own shows and the ones that come with the installer, click on the Personal and App buttons in the upper right corner of the file dialog.
A skybox renders a 360° photo in the background. The photo must be an equirectangular colourmap or a DDS cubemap. Both formats can be created by Bixorama.
Choose MEDIA > Change texture... to change the texture.
The BluffTitler installer comes with 2 example skyboxes for your to play around with:
The Effects/Picture/Skybox effect works great in the skybox layer.