A Particle System

By: Joseph Moyle

Download the demo here.

Download the Particles Project here.

Download the EmitterBuilder Project here.

Controls:

• Esc – Exit.
• Shift – Toggle particle’s geometry.
• Backspace – Toggle between controlled camera/emitter.
• Arrow Keys – Move camera/emitter.

Updates:

• Goals
  • To create a solid and robust system, that is both simple to use and easy to customize.
  • To polish the project and make it as difficult to misuse as possible.
  • To remove unnecessary expansions that I had introduced last sprint.
• Changes & Additions
  • sVector input force, which gives them a constant force that is applied to all particles upon creation.
  • Removed the variable length of the transforms array.
    • Users now have a fixed number of particles.
    • Particles are created upon spawn, and are reset rather than destroyed and created.
    • A particular particle will always be contained as the same element in an array.
      • You can use these elements as implicit identifiers.
  • Converged back into one cEmitter class.
    • Functionalities from other emitters can simply be created with a singular point emitter.
  • cEmitter‘s body is a sRigidBodyState which you can now move around.
    • This will effect the spawning position of refreshed particles, not where the currently are now.
  • EffectBuilder project is completed.
    • You can now load many different cEmitters into your game.
      • This functions similarly to how we have created other systems up until this point.
      • Specifying any field is entirely optional.
        • Default values can be set in the cEmitterBuilder.cpp.
  • How I Did It.
    • By following the same process we have used for both our cGeometry and cEffect assignments, I was able to create the builder project and binary reading load function in a timely manner.
      • This allowed me to focus on the functionality more.
      • I decided to unify my many sRigidBodyStates update functions into one per emitter.
      • This allows the game play programmer to lessen the amount of code they have to use.
    • By restricting the public accessible variables, I removed a lot of room for error.
    • Keeping the transforms array as a public facing data retrieval made it easy to keep things safe.
  • What I Learned
    • I should have put in more time thinking about how I could customize the inputs of an emitter.
    • Finishing one initial emitter first then moving on would have been a better move, rather than attempting to add functionality before I considered everything I might have to do.
    • How to more efficiently write to a binary file.
      • I didn’t fully grasp how to utilize this previously.
    • Design first.

Adding the System:

Insert These:

Example Uses:

Hot Tip: Do not call update on the emitter.body, as this is done within emitter.Update. You may, however, use the emitter.body to render something at the source if you wish.

Hot Tip: increase the maximum size of your the objects your engine is able to render to account for each of the particles!

File Format:

Hot Tip: You only have to specify the fields which you want to! You can change the defaults in cEmitterBuilder.cpp.