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.