Up until this point, the particle systems we have worked with have emitted a consistent stream of particles. We may want a point in time within the lifetime of our particle system when a burst of particles is emitted all at once. The next two input elements are burst_time and burst_particles. The burst_time element allows values from 0.0 to 1.0. This number represents the portion of the way through the particle emitter's lifetime at which the burst will occur. A value of 0.0 would mean that the burst would happen at the very beginning of the emitter's life cycle, 1.0 would occur at the very end, and 0.5 would occur halfway between. After the burst_time element is the burst_particles element. This element contains the number of particles that are emitted in the burst. Before adjusting this so that it's a large number, make sure that you set the max_particles input element to a value that can accommodate the burst. For instance, if you have a particle emitter that emits 20 particles per second and you have a maximum number of particles that is also 20 particles, adding a burst of any size will not be noticeable because there will not be enough inactive particles left in the particle pool for the burst to use.
Here is what those elements look like in the HTML file:
<span class="label">burst time pct:</span>
<input type="number" id="burst_time" max="1.0" min="0.0" step="0.05" value="0.0" class="em_input">
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<span class="label">burst particles:</span>
<input type="number" id="burst_particles" max="100" min="0" step="1" value="0" class="em_input">
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