Mdthbs

In Blender 2.80, you have options now to set a file type with it's own set of workspaces. Is there a way to rename, or better yet create a new file type?

You can add your own App Template by using the Operator Search F3 to find Install Template from File.... The underlying operator PREFERENCES_OT_app_template_install allows you to install a zipped App Template.

If you don't have a zip file you can copy and modify one of the existing templates. You can find the location of the template files by switching to the scripting workspace and typing the following code:

for x in bpy.utils.app_template_paths():

     print(x)

This will print the path(s) where the build in application templates are stored.

Each template consists of a startup.blend and a init.py. The former is the default project that is loaded. The latter is a Python script that contains a callback function / handler that is executed once the startup.blend is loaded. This allows to perform additional configurations. Below you see the basic structure of such an init.py.

import bpy

from bpy.app.handlers import persistent



@persistent

def load_handler(dummy):

    pass





def register():

    bpy.app.handlers.load_factory_startup_post.append(load_handler)





def unregister():

    bpy.app.handlers.load_factory_startup_post.remove(load_handler)

The load_handler() is the function that will be registered once you select the app template in Blender and then executed once the project is loaded. When you create your template you can add whatever additional Python code you like here. If you copy an existing template to create your own, you may want to edit this function or replace it's content with pass to make it do nothing.

Now in order to create your own template you need to do three things:

1. Either copy an existing template or create your own directory with a startup.blend and init.py
   


2. Open the startup.blend and adjust the UI to your liking


3. Open the init.py and modify the load_handler. (If you're unfamiliar with software development simply copy and past the example given above, which does nothing.)

Your new template should be available right away when you restart Blender, if you've created the files in the directory where the other templates are stored. Otherwise you will either have to copy it there or create a zip file of the directory and install it by using Install Template from File... as described at the beginning.

They are located in Blender's installation folder:
C:Program FilesBlender FoundationBlender2.80scriptsstartupbl_app_templates_system on Windows

You can see a few folders:

You can delete them or copy one of them, give it another name and save an empty startup.blend file with whatever UI you like.

The other two answers for this question both worked, but for the sake of others attempting this, I will tell you what I did.

1) I went to Blender.app > Contents > Resources > 2.80 > scripts > startups > bl_app_templates_system.
2) There I found the startup file types. I duplicated the one that closely resembled the look I needed, and duplicated that folder.
3) I went inside that folder and opened the blend file inside. I changed what needed to be changed, and compresses that folder into a .zip.
4) Back in Blender, I hit F3 and searched Install Template from File....
5) I located my new .zip and pressed accept. Once Blender was restarted, I had my new startup file.

Thanks to those who provided the answers first ;)