
284 Game Development and Simulation with Unreal Technology
Particle Size: This expression exposes each particle’s X and Y size (i.e., a particle’s
height and width) to the material. You may use the output of this expression in
a network to drive various aspects of particles’ material. Note: This expression
works on a per-particle basis.
FIGURE 5.9: Particle Size Expression Example.
Example Usa ge: Use the X or Y component of the output channel o f a Particle
Size with an opacity texture and the emissive color network of the material.
Connecting the result of this network to the Emissive and Opacity chan nels
of a material node w ill create particles ...