Welcome to this introduction to Houdini and I’m going to be introducing you to the fascinating features in the world of Houdini.
When I picked up Houdini finally got it I was completely blown away by the way that it makes you solve problems the way that it approaches things is just so dramatically different.
- Introduction to Houdini For everyone
- General Advice
- Productivity Differentiate
- Example 1
- Example 2
- The “THING”
- Houdini Lingo
- VEX vs Expression
- Attributes Vs Variables
Introduction to Houdini For everyone
And who’s it for? it’s for everybody that said if you’re already Houdini pro you’re likely going to be pretty bored it’s really to help get people up to speed on the program if they have either never used to do you need before or if they’ve tried in the stalled out. I know how it goes I tried 5 times before this program stuck in my head and now I’m here to help you get up to speed.
What we hope to do?
The goal is to really understand not just knowledge of this program that means lots of explaining we’re probably gonna stop and talk some theory.
Don’t sweat memorizing all these things don’t try and memorize each of the individuals.
I’d really like you to do is focus first on how Introduction to Houdini helps you solve problems in an interesting and unique way the rest just comes with practice.
The Houdini learning curves and everybody is talking about how hard it is. It’s hard !! yes but it’s the challenge that really comes in just how different it is the way that it wants you to solve the problems at first.
How to Tackle this?
- Use it every day, at least a little– This is the whole PRACTICE thing.
- Don’t compare it to other 3D programs.
- Do not use the self tools!- without proper knowledge don’t play around with the self tool.
- Be ok with being frustrated– It’s Houdini. It’s Hard For most people
- Bite off small problems first
- Keep a Google Doc for your own notes- There’s are lots of things to remember.
It’s a fantastic compliment to cinema 4D. it really does a great job of kind of picking up where cinema 4D leaves off in so many ways.
The other thing is it teaches you how other 3D programs work because you have access to the nuts and bolts of what goes on behind the scenes it really kind of opens up that black box that is present in so many of the other programs out there.
Houdini solves problems differently and when you’re trying to solve the problem sometimes it can actually really help to see it from a totally different perspective in Houdini really forces you to think in a completely different way.
Lastly, it’s fun to open up and play with Houdini and try something new.
I’m gonna show you a simple graph that I like to show to people who have never worked with Houdini artists or have never worked with Houdini themselves just that there’s a sense of an expectation of how the program works.
In Cinema 4d, Maya, etc
- So when you’re working with a program like Cinema 4D or Maya or really other 3D programs, your productivity is fairly linear compared to the amount of time that you spent.
- So if we have the start of our project start here in the chart. Our productivity curve looks pretty similar to this linear curve.
- So if we spent say 2 days on a project we would expect to see about 2 days’ worth of progress.
- If we spent 5 days on a project we would expect to see about 5 days’ worth of progress, so that’s a fairly linear curve.
Now when it comes to working with Houdini, that curve is actually quite a bit different:
- So at the start of the project here, you may not see any progress for quite a while, and then all of a sudden that productivity curve is gonna shoot straight up.
- This time down here is really when you spend your time in Houdini trying to figure out the instructions or the recipe that actually goes into building whatever you’re gonna build.
- All of a sudden you’re productivity curve goes off the chart because you have a recipe that you can repeat to take care of the task in as many different ways as you want.
(Cinema 4d Vs Houdini)
In Cinema 4d
So let’s say we’re going to build a chair in cinema 4D, what I’m gonna do is sit down and I’m gonna model chair after a couple of hours I might have one chair
If I’m gonna now sit down and build a new chair maybe it takes me a couple more hours.
But now I have 2 chairs we have a pretty linear progress curve.
In Houdini, we tell Houdini what the recipe for a chair is it might take quite a while to actually get there, but once we do know we can have a chair with 3 legs just as easily as we can have a chair with 5 legs or 10 legs are really tall back we can have 50000 chairs no problem.
- If your job is to just build 1 chair or 2 chairs you probably want to use something like Cinema 4D or Maya
- if your job is to build 500000 different chairs aside from questioning why you’re doing that job Houdini would be a much better tool for the task this is the advantage of working procedurally.
- This is a word you hear thrown around a whole lot when people reference Houdini in the way that it works it is a procedural workflow.
Green screen VS Rotoscoping
So another way you can think about it a related to motion graphics and visual effects is Green screen VS Rotoscoping
- Green screen is a very procedural approach to cutting something out from the background giving it some transparency
- Rotoscoping is a very manual approach to taking care of that problem both have their uses both are incredibly important but they both have different areas where they shine over the years.
Over the years I’ve taught myself many many pieces of software I always find that there is one “thing” about every single piece of software one fundamental concept that once you understand it really unlocks the program for you.
- Photoshop= layers
- After effects= precomps
- Cinema 4d= object Manager/hierchy
Houdini = DATA
- In Houdini it’s data, and to be fair all programs use data all programs are built from code all the data is there you just don’t necessarily get a chance to use it.
- In Houdini you do and that’s what makes it so incredibly powerful it lets you see and use all of the data and once you have an understanding of how to create and manipulate that data the program is totally open to you. Cool Right!!
What is DATA?
So, what is this data in? Houdini the data mostly takes the form of attributes they’re represented in Houdini’s lingo and code.
“Data” in Houdini = Attributes
Represented with a “@”
@P, @N, etc.
Attributes are number (mostly)
Integer = 1,5, -45, 150, etc.
Float/Scalar = .01,2.0, -900.4, etc
Vector = XYZ, RGB,UVW etc.
String = “Piece01”, C:\\user|…”, etc
Where do Attributes go?
Attributes live on geometry
Attributes are like “characteristics” “classes”
Can I see Attributes?
Short answer: YES
Long answer: You can use…
Middle Mouse on a node
Various views port Visualizations
And many more…
Houdini has its own Language
So let’s talk about some Houdini lingo, if you’ve ever heard Houdini artist talk you’ve heard them throughout all kinds of crazy acronyms and phrases and everything
So the first thing I want to talk about is the object context we’re really just kind of context in general,
you can kind of think of the object context as your master comp of sorts this is where you put lights and cameras and objects and everything this is all the stuff that’s actually going to render when you render something.
The “Ops” context
- SOPs = Surface OPerators
- DOPs = Dynamic OPerators
- POPs = Particle OPerators
- VOPs = VEX OPerators
- ROPs = Render OPerators
- COPs = Composite OPerators
- TOPs = Task OPerators
- CHOPs = Channel OPerators
- SHOPs = SHader OPerators
This is what the nodes look like in Houdini
The node has flags these flags do all kinds of different things:
- The one on the left is your bypass flag to turn off the node.
- There’s the Lock flag
- There’s the template flag that kind of ghosts the node
- There is the visibility flag which is probably the most important and the one that you use the most often.
Nodes can pass data via node connections to other nodes so here we’re taking the box node and we’re feeding it into a transform node where we’re actually going to move and manipulate that box
you can also see that we’ve got our visibility flag turned on on the transform node so we can actually see what it is that we’re transforming.
This is the parameter window where you actually it just all of the properties of the various nodes so when you select a node it gives you access to its parameters.
These are called channels the channels or any of these little areas that have a number or anything in it that you can actually manipulate.
Houdini has a really robust expression system built into it and you can write expressions in any one of these channels to expand its functionality.
These are the shelf tools at the top of the interface don’t touch these at least at first.
They really just note presets they’re gonna end up creating a whole bunch of notes and data for you but you’re not really gonna know what to do with it first and could just end up causing a lot of frustration unnecessarily.
- Groups are kind of like selection sets in cinema 4D, where you set a selection it creates a full selection tag for you except in Houdini.
- They’re basically just a boolean attribute your geometry is either in the group or not in the group.
- You’ll notice that most of the nodes that we come across are gonna have a little field for the group so you can actually have those nodes operate only on small portions of geometry rather than operating on the whole thing.
- Subnets are basically folders of notes that you can create in a way that’s kind of like an organization system but you can actually take them a step further and apply your UI elements to subnets and turn them into tools.
- In Houdini, those tools are called H.D.A.stand. As for Houdini digital asset and you can take a subset of nodes you can turn it into a tool and then you can use it just like any of the other nodes.
- Houdini has lots of HDA’s actually already built into it.
VEX vs Expression
- VEX and expressions we’ve already touched on expressions a little bit expressions go inside those old channel boxes.
- VEX is a very powerful programming language that’s actually built into Houdini and they are 2 completely different systems even though they share a lot of the same kinds of functionality.
Attributes Vs Variables
- We’ve been talking about attributes a ton, but there are also variables built into Houdini and there are several different types.
- There this kind of global variables that operate a little bit like tokens in cinema 4D, they’re incredibly useful
- There is this sort of older system of variables this kind of localized variables that attributes have basically come to replace over the last few years.
- So if you want an older Houdini tutorial and they’re talking about variables kind of like we would talk about attributes now that’s why they basically serve the same purpose but the attributes system is far more refined.
In this article, I give an overall overview of Introduction to Houdini. I’m not able to cover all the aspects in this article, that why I will cover in my Part 2 Introduction to Houdini article where you get a deep overview of important tools.