three.js - Adjusting opacity of individual particles

EDIT - This answer shows how to set per-point opacity using a custom ShaderMaterial. See https://stackoverflow.com/a/67892506/1461008 for an approach using PointsMaterial.

ParticleSystem has been renamed to PointCloud and then to Points.

Yes, you can create a Point Cloud and vary the alpha value of each particle's color dynamically.

In three.js, you can do this by setting the Point Cloud's material to be a ShaderMaterial having an attribute equal to the desired alpha value for each particle.

If ShaderMaterials, vertex shaders and fragment shaders are new to you, here is a really simple Fiddle that implements a Point Cloud with dynamic alphas: http://jsfiddle.net/8mrH7/266/.

EDIT: Updated fiddle

three.js r.129