If you've done much game development work, whether it is two or three dimensional, then you are aware of the traditional SubUV technique for creating particle effects. This technique involves creating a sprite sheet that represents a particle, such as fire or smoke, and having the game engine animate through the cells. This creates an animated particle that looks three dimensional but is actually a 2D texture. Here is an example of smoke:
Your first thought might be that this type of particle would be ideal for VR since we are projecting a smoke particle with a 2D texture. ...