title: Unity: Detecting taps on particles in a particle system
body: <p>I am making a scientific visualization app of the Galaxy. Among other things, it displays where certain deep sky objects (stars, star clusters, nebulae, etc) are located in and around the Galaxy.</p>
  <p>There are 6 or 7 classes of object types (stars, star clusters, nebulae, globular clusters, etc). Each object within a class looks the same (i.e. using the same image).</p>
  <p>I've tried creating GameObjects for each deep sky object, but the system can get bogged down with many objects (~10,000). So instead I create a particle system for each class of deep sky object, setting the specific image to display for each class.</p>
  <p>Each particle (i.e. deep sky object) is created at the appropriate location and then I do a SetParticles() to add them to that class's particle system. This works really well and I can have 100,000 objects (particles) with decent performance.</p>
  <p>However, I need to allow the user to click/tap on an object to select it. I have not found any examples of how to do hit testing on individual particles in the particle system. Is this possible in Unity?</p>
  <p>Thanks,
  Bill</p>