Substance Designer is an all-around great tool for texturing 3D models, but one of the features that I'm most excited about in my game development is Substance integration in UE4. Allegorithmic had already integrated with Unreal back in the UDK and UE3 days (I guess technically you can still use UDK and UE3), but they've only recently released a plugin for UE4 that doesn't require recompiling the engine for it to work.
The Substance integration is huge because not only does it mean that you can save time importing textures and creating materials by simply dragging and dropping an SBSAR file into your game, it also means that you can dynamically change any values that you've "exposed" in your Substance graph at runtime.
This is a tutorial on how to manipulate your exposed Substance variables at runtime in your game using a key press.
