There are many Unreal Engine 4 plugins allowing you to add entire new features (e.g. Substance plugin, Ultra Dynamic Sky). Once installed to Unreal Engine 4, they have to be enabled in the PiStage projects to be able to take effect in your shots.
Here are the steps:
Go to PiStage installation folder (default path: C:\PiSquare\PiStage\), find the folder named “Unreal”, open it and you’ll see three subfolders named "PiConverterGame”, “PiRenderGame” and “PiViewGame”.
Open “PiConverterGame” folder, then double-click PiConverterGame.uproject to launch Unreal Editor and open this project.
In Unreal Editor, open the Plugins Editor from the Edit menu.
Find the plugin you want from the list, enable it, then close Plugins Editor.
Close Unreal Editor.
Repeat step 2~5 on PiRenderGame.uproject in “PiRenderGame” folder and PiViewGame.uproject in “PiViewGame” folder.
Now the plugin is ready for your PiStage shots.