OpenFrameworks addon for GPU particle system written in GLSL with the possibility to use different update shader.

Based on the great ofxGpuParticleSystem.

With ofxFastParticleSystem, we add the possibility to use a separate update and draw shader to be more clear and scalable using separate shaders files.

This addon is the core for our interactive multimedia performance Dökk.

Tested with OpenFrameworks 0.9.8 and 0.10.0.

See the examples:

• example-SimpleRandom
• example-StrangeAttractor

In this example, you can see how to declare a particle system with two separate update shaders and one draw shader. You can add how many update and draw shaders you need.

This is just an example to show you how to use ofxFastParticleSystem.

You can change the update shader pressing 0 or 1.

const string CIRCLE = "circle";

To add an update shader:

addUpdateShader(string shaderName, string key)

To add a draw shader:

addDrawShader(string shaderName, string key)

To add our CIRCLE update shader:

particles.addUpdateShader("shaders/updateParticlesCircle", CIRCLE);

On the update method retrieve the update shader you want to use. If you don't specify the shaderKey, the default update shader is used:

ofShader &shader = particles.getUpdateShader(CIRCLE);

shader.begin();
shader.setUniform2f("center", ofGetWidth() / 2.0, ofGetHeight() / 2.0);shader.setUniform1f("radius", 300);
shader.setUniform1f("centerStiffness", 0.01);
shader.setUniform1f("maxSpeed", 20);
shader.end();

particles.update(CIRCLE);

Like for udpate shader you have to retrive your draw shader:

ofShader &shader = particles.getDrawShader();

To draw your particle system you have to call the draw method

particles.draw();

In this example, you can see an interesting visualization with several million particles.

You can interact with the particle system with mouse x position.