From Black Mesa: Wiki

Overview

All Muzzle Flashes in Black Mesa (first-person and third-person) are Particle-based [1].

Muzzle flashes will emit a light -- both world model and view model -- if console variable muzzleflash_light is activated (Left 4 Dead style [2]).

An advent of Episode 2, this technology means that muzzle flashes are no longer simple 2-Dimensional sprites. They are particles that exist and move in space, accurately modeling physical movement.

This allows for features such as:

• smoke that follows the gun barrel
• particles that can interact with the environment (sparks that can bounce off of surfaces)
• physically accurate cone of fire (it's actually a cone)
• and more.

This article is a stub. You can help the Black Mesa Wiki by expanding it.