Houdini 9.1 Review: Added Value and Improved Problem Solving

When it comes to crafting complex visual effects, Houdini from Side Effects ranks among the top choices. This has been attributed primarily to its flexibility and powerful procedural node based approach to problem solving. Houdini 9.1 brings with it many improvements. Most notable are support for FBX, additions to the Fluids tools, faster dynamics and animation, a number of animation tool improvements, including better muscle control, and a number of great new set of shaders to add to its rendering toolset.

Let's look at a few of these improvements in depth.

FBX Support

Having used Houdini in production pipelines, it occurs to me that most studios that use Houdini are most definitely using some other software package in conjunction. Establishing a pipeline between Houdini and a second application has always been a challenge for me. A lot of users have been asking for FBX support in Houdini and their wait is now over.

Currently the FBX importer supports the following data:

• General: Meshes Triangulated Nurbs, Lights, Cameras, Joints and Bones.
• Attributes: User attributes, UVs, Normals.
• Animation: Translate, rotate, scale, vertex caches.
• Currently unsupported: Materials and textures, Native Nurbs, Skinning.

I proceeded to test the features with small and large scenes and it does work as advertised. This is great as it really streamlines my Maya-Houdini workflow and expands the scope of data I can export from Maya. I especially like the generic user attribute support, as I can add any number of complex attributes to my Maya particles and utilize them in Houdini to drive other effects. Houdini cannot presently export to FBX but I have heard that Side Effects is working on adding FBX export functionality soon.

Dynamics

There are some new fluids tools in the Fluids shelf. First, there is an Emit Particle Fluid button, which allows you to drop in a particle fluid emitter and sets everything up for you. It will create a default emitter, or specify any object shape for the emitter. You can place multiple fluid emitters and the fluids will interact with each other.

The new particle fluid sink tool kills any fluid particle that enters a volume. The volume can be a box, sphere, object or metaball. Very useful for controlling those troublesome stray particles.

Improvements have also been made to the particle fluids surfacing options. You can now stretch a surface along the velocity of the particle. Optimizations have additionally been made to the particle surfacing, which is now 60 times faster. Cloth simulations are now threaded so that has also resulted in significant simulation time improvements. I have noticed this especially with cloth/rigid body interactions.

Character Tools

Improvements have also been made to the character side of Houdini. Muscles now have handles, which you can use to interactively shape the muscle. There are five manipulators along a muscle that you can move squash-and-stretch. This allows you to shape the muscle in any desired shape. I found this to be very easy and interactive.

There is a new Sticky tool, which allows you to stick one object on the surface of another. The source objects transforms always follow along the geometry of the target object.

The channel editor now supports import and export of keyframe animation. The editor is also much faster to interact with. Selecting a channel in the channel editor now automatically selects the node which the channel belongs.

Lighting and Rendering

The most noticeable improvement has been a huge library of material shaders, which are a more than welcome addition. There are too many to list but some of my favorites are anisotropic metals, hair, flames, liquids, volumetric billowy smoke, lava and a great sea foam shader. These are all time consuming to author and it’s a big time-saver that they are available.

Some other improvements are better performance when rendering many texture files, and improved multithreaded performance.

User Interface

The most notable change here is a slightly darker color scheme and support for selectable color schemes. Selecting large number of nodes is also a lot faster.

Documentation

Although Houdini is powerful sometimes it’s not very intuitive for the beginner. The documentation has vastly improved to help with the learning curve. That’s how I got up to speed on all the new features so quickly. For every feature, the examples are really high quality, showing off how to use the tools and outlining each attribute and what it means.

Overall, there has been much more added value to Houdini with the new 9.1 update. I’m definitely going to use the FBX importer from now on to get my data in from Maya. I also plan on taking advantage of all the new shaders that are available. Improvements to the interface and documentation have made it a lot easier for me to iterate quicker and as a result I’ve learned a few new tricks I didn’t know before. All in all, I am one happy Houdini user, and I’m sure you will be too!

Anupam Das is currently the lead artist at Electronic Arts on the Steven Spielberg project codenamed LMNO. Previously he worked for more than four years as a vfx technical director for feature films.