Particle systems are a technique commonly used to simulate chaotic phenomena, which are not
easy to render using normal polygons. Some common examples include fire, smoke, rain, snow,
or sparks. The particle system implementation that we are going to develop will be general
enough to support many different effects; we will be using the GPU’s StreamOut stage to
update our particle systems, which means that all of the physics calculations and logic to update
the particles will reside in our shader code, so that by substituting different shaders, we can
achieve different effects using our base particle system implementation.
The code for this example was adapted from Chapter 20 of
Frank Luna’s Introduction to 3D Game
Programming with Direct3D 11.0
, ported to C# and SlimDX. The full source for the
example can be found at my GitHub repository, at https://github.com/ericrrichards/dx11.git, under
the ParticlesDemo project.
Below, you can see the results of adding two particles systems to our terrain demo. At the center of the screen, we have a flame particle effect,
along with a rain particle effect.