In February of this year, at an event in London, SideFX Software released the newest version of its flagship software, Houdini 16. While I can’t cover every single new feature in this article (a list is available on www.sidefx.com) I do want to mention a few of the stand out improvements in this version and point out a few potential “gotcha’s” that you may encounter.

USER INTERFACE

Upon opening Houdini 16 for the first time you’ll notice several brand-new user interface elements. First let’s talk about the wholly redesigned network view.

Custom node shapes allow you to customize the look of your networks. Now you can make a light node look like a light bulb, the bones of a character rig look like a bone, a file node look like a file folder and so on. At first this may seem a bit gimmicky, I’ll admit when I first saw this feature I thought to myself, “I’ll never use that”. But I was wrong.


It doesn’t take long before the value of being able to use these new shapes in conjunction with the improved net-boxing, custom coloration, and notation tools becomes obvious. Especially when working with a team on a project or a freelance client – really anytime you need to hand off a “.hip” file to someone else. These new tools make it easier than ever to navigate around someone else’s work and quickly figure out what they were doing with each node or grouping of nodes in a network.

Gone are the days of switching between various wire styles to connect your nodes, but that’s ok. These new wires have some pretty amazing features. For one, when you drop a node in the middle of two existing nodes the network will automatically adjust itself to make room for the new node. Also added is the ability to route wires using “dots” and faded wires, which is fantastic for complicated data routing in complex SOP networks.

For less technical artists and others just getting started in Houdini, the addition of radial menus is a welcome feature. These radial menus are customizable and can be invoked from anywhere inside the scene view to help you create and manipulate geometry without having to worry about the network view.

TERRAINS

There is also a completely new terrain generation system that uses a 2D grid of values called a height field and a masking system as the base for designing complex large scale terrains. The system is well thought out and building with it feels a lot like using a node based 2D compositing software to build 3D elements.

One of the coolest things to play with is the OpenCL optimized erosion simulation system for weathering your terrain. You can define things like precipitation amounts, evaporation rates, how debris settles, and even specific details of the bedrock under your terrain. Then you just hit the play button and watch as hundreds of years of erosion occurs right before your eyes.


Because this is an actual simulation, Houdini generates all kinds of data that can be used to drive other elements in your scene, or be exported to your favorite game engine and used for things like flow maps.

And in the continued effort to avoid having black-boxed systems scattered throughout Houdini, the new terrain system can be used in conjunction with other fluid simulations, crowds, POPs, RBD’s and PyroFX.

BOOLEAN

While there are several improvements in the modeling tool set, by far the most improved and exciting is the Boolean (formerly called “cookie”) tool. Not only is the new Boolean fast and stable, it also has some unique features that can be very helpful in effects production. For one, it can generate polylines along the seams where two models intersect – the resulting line can be used as a source to generate sparks, dust, or fluids (think blood). Another amazing feature is the Boolean shatter. Basically, you can create and number of custom cutting planes and push them through a “solid” piece of geometry to create a seamless multi-part object that is ready to be destroyed. This means that you can create very customized shattering methods far beyond the typical options available with just the Voronoi tools from previous versions.


MANTRA

Mantra is being used more and more as a primary rendering engine in the industry today, and a new streamlined shader development workflow gives expanded access to the procedural nature of Houdini by offering a unified VOPs approach. While this does take a bit of getting used to at first, the new MAT context is very intuitive and layering multiple different shaders into a single look has never been easier.

There are also some new features available right from within the principled shader, including rough transparency and absorption. That plus a new interface make-over that includes a tab dedicated to using texture maps throughout the shader, make this is a big improvement from the previous version.


With the need for massive environments, multiple types of custom effects, and thousands of unique assets, Houdini has been gaining popularity in the world of game development. With that in mind, there is a new texture baking workflow that game artists will appreciate.

CHARACTER

There are also several updates to the character based tools in this release including Auto Rigging, a FEM based muscle system, and an all new biharmonic skin capturing workflow. Also in the realm of character effects is a newly designed hair and grooming system that allows the artist to layer and blend styling elements like frizz, clumping, bending, curling and parting while maintaining a fluid viewport experience on the average modern video card.

FLUIDS

All the above new features are amazing, but the most fascinating new features for me are the new fluid tools including the infinite ocean architecture. This system includes the ability to layer wave spectra using point instancing to avoid repetitive artifacts which in-turn allows you to create giant complex seamless oceans. But even more useful than that is the ease of blending these 2D infinite oceans together with FLIP simulated hero elements.


To achieve a seamless blend between the two systems a series of filters is applied to mask out the individual elements and control the look of the spectra on the hero wave and the effect of the hero wave on the infinite ocean elements.

New FLIP fluid enhancements also include accurate surface tension, a new suction tool, and for viscous fluids a new “slip” function which allows you to control how the fluid interacts with collision geometry.

GOTCHA'S

There were a couple of changes that caused me to scratch my head including splitting the Copy SOP into separate nodes and the new workflow for the Point SOP.

Let’s start with the Copy SOP, or SOPs I should say. There are now three copy nodes to choose from depending on what it is you are trying to accomplish: Copy and Transform, Copy to Points, or Copy Stamp.


“Copy and Transform” only has one input, so the idea here is just to duplicate geometry without the unused interface elements of stamping or using other geometry to define where the copies end up. One nice thing is the addition of the “Pack and Instance” option which takes advantage of using shared instances rather than duplicating the geometry, which in turn can save a ton of computer resources, especially in complex scenes. This was always something you could accomplish in Houdini 15.5, but now it’s as simple as one click.


“Copy to Points” is basically the old Copy SOP without the ability to transform or stamp, and “Copy Stamp” is the old Copy SOP! Why the change? By breaking the monster into smaller parts it’s easier to chew, and more efficient. It also makes the concept of what’s happening in the node more approachable, and for folks just getting started in Houdini, that’s a great thing.


The new Point SOP is a much more streamlined node that is basically an Attribute Wrangle with some handy drop-downs. The most common tasks are easily accomplished using the “Attribute” and “VEXpression” menus and include the ability to manipulate position, velocity, force, color, alpha, normal, texture, mass, and scale, as well as your own custom attributes as well. While the old Point SOP made it easy to create or manipulate things like edge force, normal force, up vectors and tension using hscript, the new Point SOP uses VEX to accomplish the same tasks. If you are new to the VEX language this updated version of the Point SOP is a great learning tool.


You can make a change using a friendly GUI in the “VEXpressions” tab, then reference the “Generated Code” tab to see the actual VEX code being generated behind the scenes.

CONCLUSION

Every new release of any 3D package comes with changes; sometimes things change for the good, and some you wish they’d just leave stuff alone. SideFX Software’s latest offering contains some of the biggest, boldest and most important changes in many years. New users just picking up Houdini will be able to pick up basic concepts and workflow easier and quicker than anyone before them thanks to the new UI / UX enhancements. Current users may scoff at the new workflow in some areas, but overall Houdini 16 is more stable, easier to use, and has the potential to impact more industries than any release before it.

ABOUT THE AUTHOR


John is the resident simulation and dynamics Curriculum Manager at Pluralsight. His deep passion for putting beautiful, explosive effects on-screen is only matched by his strong desire to teach others what he’s learned. John has had the opportunity to work at SideFX (the creators of Houdini) and teach dynamics and visual effects to numerous creative industry professionals over the years. He lives for the rush of seeing his learners experience "lightbulb" moments.

John's latest passion has been breathing new life into the Pluralsight Houdini training library, and making sure that no software or tools can get in the way of an artist expressing their creative vision.

ABOUT PLURALSIGHT

Pluralsight is an enterprise technology learning platform that delivers a unified, end to end learning experience for businesses across the globe. Through a subscription service, companies are empowered to move at the speed of technology, increasing proficiency, innovation and efficiency. For a free trial and more information, visit www.pluralsight.com