There has been some really great beginner type material coming from SideFX Houdini GoProcedural with an ongoing look at getting really great foundation into learning SideFX Houdini.
This installment provides a look at Houdini’s particle systems the Particle Operators (POP and SOP) networks to provide a foundation for using particles in Houdini as well as forces, charges and even how to render out the results.
