The first class deals with setting up Houdini to work with VEX and VOPs and starting to get our feet wet with writing a few geometry deformers in SOPs. We will be talking through the theory behind Laplacian and Taubin smoothing and learn how to implement those algorithms in VEX.

One of the fundamental principles in VFX is noise. We will be looking in detail into the theory of noise and learn some specific terminology and compare different functions in small VEX examples. We will then go ahead and implement our own fBM functions which we will then use to create procedural effects like a fireball and lightning. We will touch upon how to treat noise functions on animated characters and then slightly bend our minds to create amazing patterns using the concept of domain warping.

Main topic of this week is geometry creation. We will be growing some grass curves, implement features on how to even animate it, and learn how to turn them into polygonal geometry we can render. We move on to implementing our first SOP solver to create some actual animated lightning –applying what we learned about noise and geometry creation.

This week focuses on the great Grey Scott Reaction/Diffusion model. We will learn about its theory and how to implement it in VEX. With the resulting setup we will experiment in various ways, to create some amazing naturalistic looking pictures.

Another often used method is flocking. Used for birds, fish or spaceships, the flocking mechanism by Reynolds – often referred to as BOIDS – is a fundamental principle driving many workflows in VFX. We will look into BOIDs theory and then learn about and implement a full flocking setup with behaviours like separation, alignment, wander and cohesion and instantiate geometry to the simulated points to create a flock of birds.

Growth algorithms are an important part of VFX work. Veins, magic, plants and other vegetation can be created with space colonization algorithms. We will be looking at the principle of seed and feed points, create ivy overgrowth and bushy plants to populate a 3D scene, making it more believable and life-like.

After dealing a lot with polygonal geometry, our focus will shift to other primitive types. We will be looking at the principle of advection by moving points and volumes through a velocity field and also implement a volume displacement setup to create cloud like effects. We will learn how to use point replication to increase the detail of point renders in a geometry context but also as a render time procedural. We will extend that excursion into rendering land by writing a more complex procedural that turns points into fur at render time.

We finish off the class by learning about concepts of Thermal and Hydraulic erosion. We will apply those algorithms to write our own VEX setup, creating highly realistic landscapes to be used in VFX or Games.