Deborah R. Fowler
Houdini Quick Reference
Posted June 6 2019
Updated Sept 1 2022
In response to student requests, this guide is my biased opinion of what resources are available to help you learn Houdini. There are more in-depth resources on my website, but this is designed for students getting ready for next quarter.
First let me say the SideFX documentation is
excellent and clicking the ? button in Houdini to bring
up the floating help is the best textbook you can have!
Second, I do have a list of
select tutorials - there is an ever growing list as we are
in a fast paced industry.
This quick reference is intended to be more of a step-by-step guide to get you started.
The overview on my website is
designed for beginning users. I have also several recorded
instructional videos
on vimeo and youtube.
By the way, if you are new to
computer graphics, it would be useful to familiarize yourself
with the concepts in a book such as Fundamentals
of Computer Graphics (available
here too). I recommend you review the sections on
Miscellaneous Math (Trigonometry, Vectors) in particular.
Getting Started
Houdini is free! Download the apprentice version as per the instructions. Be sure to grab the production
version that matches the version used with the educational
license.
Installation should be a breeze - but if you do run into
difficulties there is an FAQ (and
instructions for Windows/Mac/Linux)
First off familiarize yourself with the interface - if you have already used a 3D package this will look familiar in many ways.
- very basics in my Houdini
Essentials video
- SideFX has great resources for getting started https://www.sidefx.com/learn/getting_started/
- there are also transition guides on that above page from
Maya or Softimage that may be helpful
- both written and video format
Once you are comfortable in the interface there are many avenues
to explore. Roughly on the left of the display at the top shelf
are the basic operations, on the right many of the advanced
features such as dynamic simulations. Keep in mind that Houdini
just keeps making the software better so the tutorials you find
about things on the right change, however on the left are stable.
This is a generalization.
Diving in, you can work in whatever way is most comfortable to
you - interface, shelf tools or node network - that's one of the
strong points of Houdini - flexibility. Houdini has a
non-destructive node-based procedural workflow.
I tend to work in node networks and as you become more familiar
with Houdini and start creating your own nodes you will too - but
you don't have to start there. Start with the basics first.
Node Networks
If you have used a node based application before, Houdini will
look familiar. Nodes are "cooked" top down in the SOPS (geometry)
context. Where your display flag is determines what nodes are
processed.
Nodes represent everything in the Houdini world from geometry to
lights to dynamic systems. Along with these nodes data is kept and
attributes are associated with these nodes. This information can
be seen by MMB and also in the Geometry Spreadsheet.
Attributes, much like nodes, have context. Attributes can be
point, primitive, vertex or detail. Do you need to know this? Not
now but you will find this helpful in the future.
Code
Another extremely valuable feature of Houdini which for me sets
it apart from other 3D DCC (Digital Content Creation) packages is
the ease in which code can be integrated into the network. In
Houdini you can create expressions directly in parameter fields,
as well as create your own nodes in python or vex snippets, as
well as in the more conventional script editors. The ease in which
you can customize using hscript, python and vex are remarkable.
(HDK uses C++ but is less widely used, particularly with the
introduction of the wrangle nodes in version 13).
My personal favorite now is vex snippets in point wrangle nodes. If you are interested in learning vex it is very C++ like and the rules of syntax are practically identical except for the @ sign. The @ sign indicates an attribute creation or fetch on that attribute if it exists.
For resources on VEX:
- build a snowman in vex
video and explanation
- my sample files - a
collection of practical examples that have come up
- tokeru.com (also know as CGwiki and is Matt Estela) has an excellent website as well as his Joy of Vex lessons (Vex in 20 days)
For resource on Python in Houdini:
Going further
Start by building something, anything. Next try a procedural building (make it prettier and more detailed)
- One way to build a house
- https://vimeo.com/247357809
- if you prefer written over video, you can also start
here
Also by others:
- believability in procedural modeling Anastasia Opara https://vimeo.com/228391688
- also game dev tool https://www.sidefx.com/tutorials/building-generator/
- and Anastasia's Procedural lake village https://www.anastasiaopara.com/lakevillage
Additional tutorials (not in a particular order) are:
- SideFX has a section on Talks & Webinars which you can search
- They also have a list of Tutorials which include masterclasses (advanced)
- Entagma - considered intermediate - https://www.sidefx.com/learn/collections/entagma/
- Manuel Casasola Merkle, Moritz Schwind - Motion Graphics
Designers
- Peter Quint
- includes project files
- Anastasia Opara
- Scott Keating - Senior Product Designer at SideFX Software
- past tutorials he has created a Volcano, Waterfall, Corn Maze (instancing) which at this point are a bit old but still have good information
- more recently rigging
- Jeff Wagner - "old_school" - all the Illume Webinars, particularly recent ones
- More advanced to look for are: Jeff Lait (SideFX
mathematician), Cameron White, Steve Knipping (Advanced)
- If you are interested in Games there is an entire community as well
At SIGGRAPH, FMX, GDC conferences, SideFX always records their
sessions and makes them available, so watch for those as well click
here.
Everyone learns at their own pace in their own style and Houdini
allows you a tremendous amount of flexibility in this regard. Once
you learn the basics, pick a topic and dive in!