Emissive Material Not Lighting Surface

Emissive lights just straight up don’t work as you’d expect in unreal, I don’t even bother with them.

If you use a point light (you should) you can easily make it’s intensity flicker within a blueprint. It doesn’t have to match the material at all, as the quick flickers of small lights will be hard to distinguish a difference. I use this with candle light all the time.

Also, make sure to turn off ‘use inverse squared falloff’ in the point light (you’ll need to drastically reduce the intensity). This will turn it into more of a wider area light rather than a central light source, which will fit your trees better as they have a number of spread out ‘lights’.

Thanks Juice. I have heard many say the emissive is not very good in UE4 but then I see the results posted by Makigirl and other tutorials. However, I think it makes a difference if it is in an interior scene which most seem to be. I think your ideas could work for what I need but I keep pushing to find if it was my lack of understanding that was causing the problem.

So funny thing is the ground mesh has a lightmap rez of 512…which should be enough I would think. However, I am tempted to try a new scene and see what happens if I keep it simple. Here is another tutorial where again, they are getting the effect I want but notice, it is not in an exterior larger environment.

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In the emissive screenshots I’ve posted… just the inner faces of each wall had 1024 res lightmaps!! …so maybe 512 is a bit low for the whole ground…
Just duplicate your ground mesh, scale it down, place it next to/under one of the christmas lights and build it on medium…
…haven’t watched that tutorial but the final result looks cool! :slight_smile:

In this attachment, I use a point light in a quick setup as Juice suggested and it does create the effect. I am disappointed though that i need to take this extra step to add more lights to the scene and then I will need to blueprint them to get the various blinking results I need. I just do not understand why my emissive lights are not doing this on their own as I have scene in other tutorials.

Just to clear other possible issues: did you try applying your emissive material to a larger object (like a big sphere) and rebuild the lighting to see if it’s working?

Hello Manoel, Funny thing, that was one of the first things I did. I think I added a huge square and it seemed to worked better but not quite what you would expect.I kind of attributed some of my issues to the size of my meshes for the lights but the issue with that is that even though the meshes are small, there are many of them. Actually, in UE4, the string of lights fro each object are a single mesh since I had combined them all within 3ds Max. With that, I thin I should have seen some sort of result where the light would reflect back from ground surface.

Here is a sample of a real scene where you can see the effect on the ground as it should be.

Hi arcltek,

If I’ve understood you correctly, your goal is to create several identical meshes with emissive materials that flicker and update the ground in real time.

Emission is very basic, and not dynamic. It only works with baked lighting, and may not be high quality as you have seen. If you want several copies of a mesh doing the same lighting system, you might build an actor that has a light that flickers attached to it. You can then place many instances of this actor around your scene. That saves you the manual work of doing different lighting for each placement.

If I’ve misinterpreted, could you post a short description of what you want to do and see from start to finish? This might make it easier for us to give you the best workflow for unreal engine.