Light Propagation Volume + Additive Blending

Hello. I’m trying to achieve this look:

Specifically, the traffic streaks via timelapse photography. Note the lights from the road/cars hitting the sides of buildings.

I’m doing this with Light Propagation Volumes. I know this feature is experimental, but still, it looks awesome.

I got it more or less working:

However, it looks bad. The non-lit areas are black, covering the road. When I stack traffic paths on top of each other, z-fighting happens. What I really want is to have this be additive, like so:

This looks great! BUT: As you can see, LPV does not activate here. How can I achieve both?

One possible solution is to have two versions of this mesh, one that’s emissive and one that’s additive. However, I can’t make the emissive one invisible without also having LPV turned off.

Any ideas on how I can do this? Thanks :slight_smile:

Have you considered simply placing the emissive objects underneath the road?