Night Vision(Toggle in real time)
Step 0. Let's make night vision system just like a kind of 'witcher sense'. Step 1. It's very easy to make the system in Unreal Engine 4. Make a material from 'Material Parameter Collection'. Step 2. Use the material collection parameter. These are example screen shots. Assign the materials to the meshes in the level. Step 3. Change scalar parameter values when user press or release 'V' key. You can make a smooth change with a timeline component.