After reading the thread at Vehicle tail lights - Blueprint Visual Scripting - Unreal Engine Forums , I tried to use meshes and materials to simulate working vehicle lights but I don’t know how to set up the lights in vehicle blueprint. How do I set up meshes and materials instead of spotlights to simulate working vehicle lights?
You need to have a material that you can alter at runtime, Dynamic Materials.
Check this video
You need to do this to change the emmissive component of your vehicle mesh. The taillights should emit red when brakes are on. To achieve this look, you need a dynamic material.
However, emmisive materials don’t really emit light that shines on other stuff in your game world very well… so you need to add some sort of light components that you turn on and off in tandem with the dynamic material.
Check this video series to learn to switch light on or off, from video 16 onwards: