The Point Cloud Particle System

A PCS is a single updatable mesh with the the PointsCloud property of its material set to true. The point particles are simply the vertices of the mesh. As a mesh a PCS has most of the properties of a mesh, The exceptions are those related to its material which is already set and cannot be changed and also anything related to its vertex normals and indices as it does not have any set.

As a particle system the PCS provides some methods to manage the particles. However it is behavior agnostic. This means it has no emitter, no particle physics, no particle recycler. You have to implement your own behavior.

Particles can be added to a PCS with a function or using an existing mesh as a model, where particles are randomly evenly distributed on either the surface of the model or inside the model.

The expected usage is:

  • First, create your PCS with new PointsCloudSystem().
  • Then, add particles in the PCS, using one of addPoints(number, function), addSurfacePoints(mesh, number, method) or addVolumePoints(mesh, number, method).
  • Redo the additions as many times as needed. Each addition creates a new group of particles identified by particle.groupID.
  • When done, build the PCS mesh with buildMeshAsync().
  • Changes to particle properties can be achieved with the initParticles() or updateParticle(particle) methods and a call to setParticles.
  • Particle animation can be accomplished by defining their individual behavior in updateParticle(particle) and calling setParticles() within the render loop.


The way the PCS is created using vertex points with a pre-applied material with PointsCloud set to true means that:

  1. Particles cannot be destroyed and particles off screen are still enabled;
  2. Transparency does not work on individual particles.