The majority of the concepts for this course apply to any version of Houdini, however this course will be taught using Houdini12 with special focus on the work-flow techniques and improvements available in this new version. You can work through all of this course using the free Apprentice version of Houdini available at
John started working in VFX over ten years ago and has experience in Houdini, Maya, 3ds Max, After Effects, Shake, Nuke, and just about every NLE you can think of. John just wrapped up 6 months working at Side Effects Software Inc. in Santa Monica where he created a library of Houdini training courses on FLIP fluids, DOPs and VOPs for industry professionals from various studios including Blizzard, Sony Entertainment and DreamWorks. He has one insane long-haired cat, horrible allergies, and is currently pursuing his Masters of Fine Art degree in Visual Effects at Savannah College of Art and Design.
We discuss an overview of the course, what the different OP's are (DOP's, POP's, ROP's, COP's, SHOP's, and so forth), how to customize the interface, special ways to access help and other information inside Houdini, external resources, and a short discussion of the project for class 02.
The information in this lesson is meant to cover the gaps that I have found in the Getting Started documents on the SideFX website. Please review these basic concepts of 3D and simple UI controls. This will leave more time for working the projects and we can focus more on the Houdini specific information.
Attributes, Expressions, and Copy Stamping
We dive head first into creating systems in Houdini12. Our first project is to create a scene where a gopher crawls under a field of grass blades. We use expressions to create procedural animation, attributes to modify geometry, and copy stamping to randomize properties of secondary geometry.
This is our first look at the truly procedural workflow of Houdini and the power of creating elements through the use of expressions. In this lesson we build a network that will stand as the foundation of our first Houdini Digital Asset which we will build in the next lesson.
There is a file (hou102-class02-gopher_v01.hip) included that has the system we build in this lesson. The file has notes and descriptions of each node in the network. Please work through the lesson recording first before looking at the included file. It will help you to understand each step as you learn. Then try to rebuild the system from memory using the reference file only when you need a guide.
We look at the different light types available to us and learn when and how to use the most common. These light types are point, spot, area, distant. This lesson covers the basic parameters of lights, shadows, and attenuation.
We take a brief look at the Mantra ROP and the most commonly adjusted parameters. We focus primarily on the Micropolygon rendering engine and the shading and sampling tabs. Here we discuss the new unified memory cache in Houdini 12 and how to use it to get more efficient renders from systems with plenty of ram.
Finally we look at how to access basic materials and how to apply them to our models. We examine the SHOPs context as a way to adjust the look of our shaders and briefly look at the guts of a shading network. This all leads us to the next lesson where we will be covering visual programming with the VOPs context.
We examine using VOPs to create shaders. By creating three shaders, snow capped mountains, cracked earth, and procedural grass, we learn the basics of the VOP's and SHOP's contexts. We also explore customizing the shader interface to create a usable asset for the pipeline.
The shaders we develop in this lesson will be used in future projects.
We take our shaders a bit further and integrate them with a particle effect to grow grass in our cracked earth. This lesson looks at the fundamentals of particles and includes a first look at using VOPs outside of the shading context to create a noisy particle emitter.
Week six explores the world of Houdini particles. We cover the basics of working with particle mass, acceleration, and velocity, and take a look at the most useful nodes in the POP context while building our first small project.
Rigid body dynamics is the focus of week seven. We look at the basic concepts of dynamic simulations and navigating the new world of DOPs. We discuss the most useful nodes in the DOPs context, and we take a look at the capabilities of the new Bullet solver. We also cover some useful tips to making your simulations more efficient.
We take a look at fluids in Houdini. The lesson starts off with a brief overview of Volume fluids, SPH Particle Fluids, and then Houdini 12's FLIP solver. Then we examine the most important aspects of creating a FLIP simulation and some of the basic techniques for controlling the motion of the simulation. We also take a brief look at the new volume sourcing tools in H12. The conversation on volume sourcing will be explored further in a later lesson on the new smoke and pyro solvers.
In this lesson we pick up with the surfacing of fluids. We cover the most useful parameters for dealing with the particle fluid surface node, filtering, and speed stretching.
Then we move our focus over to smoke, the doorway to pyro. We cover how temperature is the key influencer to the overall look of a smoke simulation. This section also covers one of the most useful tools in the dops context, the ability to visualize fields. We look at density as smoke, temperature as a slice and velocity as streamers to get a good overall idea of the different visualization techniques.
Then we talk about the key parameters of the smoke solver, Timescale, Temperature Diffusion, Cooling Rate, Viscosity, and Buoyancy.
With a firm understanding of how these parameters are calculated and how to view them in the viewport an artist can manipulate the character of a smoke simulation.
In the next lesson we discuss the pyro solver and transfer the techniques we learned with the smoke solver into a more complex set up.
We take a deeper look at the pyro solver. We discuss the similarities between the smoke solver and the pyro solver as well as more advanced methods of shaping the character and details of your flames and smoke.
We also cover the different methods of visualizing these controls for the most efficient tuning of the look for your simulation.
Finally we look at the new H12 clustering system and discuss the benefits and downfalls of working with clusters.