Once you have the Flipside Creator Tools installed and set up, here are the steps to create a custom prop kit you can import into Flipside Studio.
Prop kits start as scenes in the Unity game engine. A prop kit is a collection of related props that are bundled together via this Unity scene, but can be used individually in Flipside Studio.
Each prop kit is its own Unity scene with a single game object in it that has a PropKit component on it. Each prop kit has a list of props, which are each their own Unity prefabs that live outside of the prop kit scene.
1. In Unity, go to Flipside Creator Tools > Create Prop Kit. This will open a new Create Prop Kit window.
2. Enter a name for your new prop kit under the Kit Name field. When you've entered a valid name, a Create Kit button will appear.
3. Click the Create Kit button. This creates and opens a new Unity scene that contains an empty prop kit and put it in a new folder, along with a Prefabs subfolder where the prop prefabs will live.
4. Double-click the Prefabs folder to open it.
5. In the main menu, choose GameObject > 3D Object > Cube to create a cube object. This will create a new cube in your prop kit scene.
6. To turn it into a prefab, drag the cube into your Prefabs folder, then delete it from your prop kit scene. Save the scene then double-click on the newly-created Cube prefab to open it.
7. Select the root Cube element in the Hierarchy window then in the Inspector window, click Add Component and type PropElement. Select it to add it to the object. This turns it into a prop prefab that can be included in a prop kit.
9. Navigate down a folder in the Project window and double-click your prop kit scene to reopen it. Select the root object in the Hierarchy to highlight it.
10. On the PropKit component in the Inspector, increase the Prop List from 0 to 1, then find your cube prefab and drag it into the first slot and give it a name. It should look like this when you're done:
You now have the most minimal prop kit with one prop included in it.
When you're ready to build your prop kit and test it out in Flipside Studio, open the Flipside Creator Tools window by going to Flipside Creator Tools > Open Creator Tools.
Click the Build & Publish Prop Kit button on the Creator Tools wizard. Unity will begin the asset bundle build process, which can takes some time to complete, and may take longer the first time. When the build process has completed, you'll see a progress bar appear under the Build & Publish Prop Kit button showing how far along you are in uploading and publishing your prop kit.
When that's finished, you can find your cube prop in Flipside Studio under the Imported category of the Props menu.