I'm seeking a way to get a volume shader applied to a sphere such that a gradient ramp is represented omnidirectionally around a point. In this case the goal is to show the amount of noise in dB surrounding an aircraft taking off. This screenshot is from another package, and I'm new to Houdini. Hoping someone can suggest a way to achieve this effect in Houdini.

It would be great if the gradient was procedural, so I can do lookups on the value as it contacts other objects.

Thanks!