string key -- Key to look up the effect from. string surfacetype -- surfaceType to look up any special effect from. vector origin -- Origin to play the effect at in world space. vector endOrigin -- End position for the beam. boolean loop -- Whether the effect should be once only, or loop.
- The key must start with 'fx_'.
Looks up an effect on the entity and plays it at the specified position in the world, and returns a handle to the effect. If a special version matching that of the surfaceType passed is found, that will be played, otherwise the exact key name will be used.