How to get volumetric fog in half cone shape. Think wide street lamp.

Hi there,

Thank you for taking the time to read.

I am trying to create an effect similar to the cone of a street lamp on a foggy night but with a much larger source area than a point. Imagine a cone (pointy end up) but cut in half horizontally across the middle. I want the lower half as a fog volume and light source under some large discs.

I cant use a point light as half the fog cone would appear on the top of the disc. Rect lights don’t really work as at certain angles the ‘corners’ are visible unless I scale the X/Y down, but that has the opposite affect in that the volume doesn’t reach the extents of the light emitting disc.

What would be the most cost effective way of doing this? A half cone mesh with fresnel kind of works from a distance but doesn’t look great when the player is intersecting / inside the half cone. I have read/watched tutes about particles with a fog volume material but I couldn’t get the particles in the half cone shape I wanted.

Any help would be most appreciated.

Thanks
JJG