### 3.5.4 Halo

Earlier versions of POV-Ray used a feature called `halo` to simulate fine particles such as smoke, steam, fog, or flames. The `halo` statement was part of the `texture` statement. This feature has been discontinued and replaced by the `interior` and `media` statements which are object modifiers outside the `texture` statement.

See "Why are Interior and Media Necessary?" for a detailed explanation on the reasons for the change. See "Media" for details on `media`.

More about "Media"

- 3.6.2 Media in 3.6 Interior & Media & Photons
- 3.8.11 Media in 3.8 Quick Reference