The goal of the Game Art and Animation program a.k.a. GAA is to prepare you to enter the wonderful, creative and satisfying world of game art creation. You will learn various tools and workflows to achieve this over the duration of this program, with each individual course covering an aspect of the workflows required to achieve this.

In Procedural Modeling I, we will explore Houdini as our main 3D modeling software, and use it to build geometry that you will then be able to incorporate in your 3D game engine of choice.


In this section we will quickly go over some of the basic fundamentals of 3D. A quick introduction from Wikipedia covers the high-level concepts. Here’s another interesting (and slightly longer read) that covers what 3D modeling is all about.

For our purposes, these are the important points you should know. These apply to the majority of 3D software:

  • Modeling – the representation of an object/creature in 3D digital space (realism not required)
  • Cartesian Coordinate Space – this represents the coordinate system used to place 3D models in 3D space, named after René Descartes, (he of the famous saying “cogito ergo sum“).
    • Origin – the fixed point of the Cartesian Coordinate System, denoted as (0,0,0) and from which all coordinates emanate from
    • X,Y,Z axes (plural of axis, not the chopping tool) – The 3 directions used in defining 3D space. Note the colour scheme (red for X, green for Y, and blue for Z). These are standard notations for the axes in 3D software.
      The axes follow the Right-Hand Coordinate system. The direction the arrows are pointing is the Positive axis.

      (examples of axes in Maya and Houdini)
    • Units – each software have their own unit system. For the most part, they are based on the decimal system i.e. centimeters, meters, etc.
  • Model (Mesh) types – the two main types of mesh types found in 3D are polygons and NURBS.
    • Polygons – shapes made of flat planes consisting of Primitives, Edges and Points (Houdini) or Faces, Edges and Vertices (Maya).
      Potato or Potato – same thing, different nomenclature. The important thing to remember is this:
      • Point (or Maya vertex) – a single point in 3D space that has coordinates. Not visible during renders (usually)
      • Edge – line that connect two points. Not visible during renders
      • Primitive (or Maya Face) – a closed surface made up of a minimum of 3 points and 3 edges (triangle). Visible during renders
    • NURBS – Non-Uniform Rational B-Splines (say that quickly five times). Mathematical equations that calculate the surface of an object. The points and edges are connected by splines, rather than straight-segments like in polygons.
      NOTE: We won’t be using NURBS for the most part in this program, since game engines do not support them. We will cover them in more detail once we start doing more complex stuff in the course.
  • Transforms – the manipulation of objects/components in 3D space
    • Translate – moving an object in 3D space
    • Rotate – spinning an object
    • Scale – increasing or decreasing object size
  • UV mapping – the application of 2D textures on 3D objects


The term “proceduralism” in 3D – and specifically in Houdini – is an approach that lets you “use stuff to build stuff“. In other words, use specialized nodes that do specific functions, chain them together, and ultimately use them create your creative vision.

I know, not very clear and very abstract.

Let’s use IKEA’s ubiquitous Billy(tm) bookcase as an example:

(I think everyone had one of these at some point in their lives…)

Now, in a traditional 3D workflow, you would build it like so (I’m using Maya for this example):

But let’s say that your Game Designer lead suddenly decides at the last minute that they need variation in their bookshelf builds in order to make the game environment more interesting and they require these types of shelf variants pronto:

Other than pulling your hair out and grumbling to yourself why they couldn’t have asked you two weeks ago rather than two hours before the game goes Live, you would go back and rebuild new models of the bookshelves, indivdually adjusting the height to match the number of shelves, and on and on.

Well, with a procedural approach, all this is becomes a nightmare from the past, and you can do that in minutes flat-  and still have time for a full Grande foamy latte with a crumbly biscotti (once Starbucks opens up again after the pandemic).

Ladies and gentlemen…Houdini!



As you see in the example above, Houdini has a lot of power. The trick is knowing how to harness that power.

Traditionally, 3D Digital Content Creation software (DCC) such as Maya, 3DSmax, C4D, Modo, Blender et al followed the credo of “building  one-off’s”. In other words, build one model at a time. For any variation, the model has to be either rebuilt from scratch, or duplicated and modified manually.

Houdini takes a different approach, where rather than building the single model, you build the idea of the model. By planning ahead and thinking through the possible end results, creating those future variants is incorporated into the modeling process from the very beginning. The results speak for themselves, and that’s where Houdini truly shines.

Now, not everything is wonderful on the greener grass side of Houdini. To create unique models, using intuitive and tried-and-true workflows, the traditional DCC’s are would still be considered first, including digital sculpting tools like Zbrush.
Houdini’s does have traditional modeling tools in its toolset, but – as of this writing – might be a bit lagging behind the other software.

Another advantage the traditional DCC’s offer is very specific creative control over the modeling process. Again, this is very useful to create one-off models i.e. statues, or unique artifacts.

The learning curve of Houdini is also quite steep, relatively speaking. But once that hurdle has been cleared, you will find yourself using Houdini as your main 3D software, and use it to build the majority of your 3D assets, while occasionally using the others for those very specific tasks.

In this program you will learn both approaches and hopefully gain the experience and skills to know when to use each type of modeling tools.

NOTE: Many of the traditional DCC’s are trying to incorporate procedural workflows into their software (i.e. Maya and Modo). But they are nowhere close yet to unseating Houdini from the procedural throne.


Please read pages 1 – 63 of the Houdini Foundations PDF booklet, found in the Files section of Procedural Modeling I on MS Teams.

Work through the Soccer Ball assignment (until pg. 63) to familiarize yourselves with the Houdini nodal workflow. Feel free to read up the whole booklet.

NOTE: Use either Houdini Indie or the academic version. Do NOT use Houdini Apprentice. 

If you have any questions, post them in the Posts section of by starting a new conversation.

Make sure to have Houdini tested and running properly before the beginning of class.