Need help with getting a dynamic emissive material set up working

I’m trying to set up a dynamic emissive material that can be used in simulating a traffic signal light
set up.

I want to eventually set up the traffic light as a class blueprint which I can then place in any game level

and use a local level blueprint to make adjustments to the timing of lights on the adjacent streets.

For now I’m just trying to get one material to switch on it’s emissive property when you start the level.

I’ve looked over the blueprint content example map and also this tutorial:

and this discussion:

Here’s what I’ve set up so far:

The material

I set up scalar vector to control the emissive level

The construction script:

DM_Light is the material instance dynamic

Event Graph:

I had pretty much this exact problem. After 4 hours I figured out what it was: When you edit the material, you have to click the “Apply” button when you are finished. Yep. 4 hours. You can understand how I was very frustrated.

Hopefully that’s the issue you’re having too. Let us know if that fixes it or not for you. Your graphs look fine on quick inspection.