Hey all,

I am trying to make bullet trails that match the look of the trails made by the rail gun in the movie Eraser (here is a clip for reference: Eraser Rail Gun [youtube.com])

What it looks like to me is that they have a volume that has the solid property of metaballs, but then dissipates with a very high viscosity to cause the swirling. I have tried to convert metaballs to a fog volume and then use that as the density is a volume emitter, but still can't get the look right.

I think the key thing I am having issues with is the shader, getting that ramped look like a normal falloff with geometry, but I can't really figure out how to do it with volumes. I don't even know if that would be the way to solve it, that seems like just one piece. This way they dissipate seems to be an issue as well, I tried the dissipate microsolver, but couldn't get it to work. Attached is a version of a hip file I was using.

Any help/suggestions would be greatly appreciated.