Eneroth Fog Tool
Set fog start and end distances precisely from points in model or custom lengths.
Eneroth Fog Tool

Activated from Tools > Fog Tool.

Set fog start (where opacity is 0%) and fog end (where opacity is 100%) either by clicking in model or by typing in lengths.

A typical use is to make paralell projected sections look more 3-dimensional by clicking the section plane to start fog at it and then type in an exact length of how deep into the model to see. This also hides what's not relevant for that specific cut which is useful for clear drawings.

Another use is to make heightmaps, e.g. of landscapes.

When fog thickness is negative (the fog end is closer to the camera than the foig start) no fog at all will be rendered.