Featured Artist: Phill Mayer, Los Angeles
Hi, I’m Phill, an FX Artist with experience working in the film and commercial industry out of Los Angeles, California.
While I use many tools to create, Houdini is usually my tool of choice. Heavy simulations, procedural modeling, animation, lighting, and rendering all benefit greatly from Houdini’s flexible and directable workflow, allowing for agile changes and an improved quality of life for artists. I want to say thanks to SideFX for creating and improving upon an already amazing toolset version after version. After using Houdini over 8 years I can say that if you have been curious about procedural workflows, now is the time to start using Houdini. It has become much faster and user friendly, especially in regards to modeling, lighting, and lookdev, while maintaining its world class simulation environment to accomplish almost anything you can imagine.
How I got started
I was always interested in computers, graphics, and gaming. From a young age I was building my own computers and trying to get the best performance out of them. Gaming got me into computer graphics, but visual effects and rendering really peaked my interest in terms of their photo-real look, complexity, and high computational demand.
While I was still in high school I started learning Maya and Realflow as part of a video and multimedia class. After the first couple simulations and renders of splashing water that I painstakingly waited for weeks to render I was hooked. It’s amazing just how difficult it is to fill up a glass of water, simulate it splashing, then render it and have it look even somewhat photo-real! While it was a challenge and for the most part enjoyable, I thought that there should be a better way to direct the simulation and keep it all in a single package. I had heard of a tool called Houdini that artists were using in production of various films that had inspired me. I decided that I wanted to get serious about working in the VFX industry and learn the best tools out there. I went to SCAD (The Savannah College of Art and Design) to further my education in visual effects and hopefully land a job doing what I loved. I was fortunate enough to take Houdini classes by the brilliant fine artist Ken Huff. His inspiring digital works of art are mathematical and intricate, but still have a very organic, tactile quality to them. I still can’t thank him enough for a strong foundation in all things Houdini - digital assets, proceduralism, scripting, and rendering. After my years at school I managed to assemble a collection of student projects that would help me break into the Vfx industry.
My first job: Harry Potter
My first professional venture as an FX artist was working on Harry Potter and the Deathly Hallows Part 2 at Gradient Effects in Los Angeles. This was quite a challenging project to work on, but it was very rewarding to see the sequence I helped create play in the final film. I focused on the ‘Snape’s memory’ portion and worked primarily on flocking simulations of willow leaves that magically came to life and flew away off of the trees.
This was an interesting effect to develop for a few reasons. The ‘willow flies’ needed to be positioned in a natural resting pose on the willow tree and match the existing foliage. Gradually the willow leaves then had to come to life, unfurl, and detach from the tree and start flying in the correct direction. They couldn’t fly randomly, but had to act coherently as a group, similar to a flock of birds. Houdini’s pop tools, grouping, and vops were all used together to really control and direct this effect. Gradient Effects had just started to use Houdini and I was happy to help set it up and integrate it into the pipeline. I could already see how important a procedural workflow was to delivering superior results and how an efficient rendering pipeline can make a big difference.
Working on Gatorade and Call of Duty
After working in films I moved to the advertising industry. I have been working at The Mill in Los Angeles for over 4 years now. Comparing commercial and film production there is definitely a bit of a difference in terms of turnaround time and length of the end product, but the work done by artists is still very similar. If anything, speed and directability are even more important, and yet again, this is one of the reasons I have come to rely on Houdini. One of my favorite projects: Gatorade - “Fierce”, was a great showcase for fluid simulations and rendering in Houdini using Mantra.
Everything in this project was very controllable and it was easy to apply a similar look to a large sequence of shots. I helped to develop a toolkit of digital assets that artists would use in their scenes. This allowed all the specific simulation behavior, attributes, and AOVs for rendering to be consistent. Keeping the simulation and rendering in the same program was also crucial to the success of the project. Performing large exports and imports would have added a day or more onto iterations and would have required someone at the studio to manually submit a render when the simulation finished at 3am. Houdini’s unique dependency workflow in Rops was able to traverse large trees of simulation and rendering steps overnight to iterate the project quickly and painlessly.
Another noteworthy project I worked on was in game cinematics for “Call of Duty: Ghosts.”
There were lots of opportunities for simulation and procedural effects to create an immersive abstract world. Many times an effect would need to form one of the graphic motifs, such as the call of duty ghosts skull logo. In one instance we had a cloud that needed to be shown in the shape of a skull. Houdini’s simulation tools combined with custom forces allowed for accurate responses to specific art direction. There were water simulations, explosions, procedural cities, fractures, destruction, and plenty of rendering done using Mantra. Again, the procedural nature of Houdini was the perfect choice for this unique project, as it allowed for creative freedom, which in turn helped drive the look of the finished product. Digital assets for vdb meshing, clustered simulations, custom forces for simulations, lighting, and rendering allowed the team to collaborate easily together and share tools as they were being developed.
My personal Houdini project: ink simulations
Throughout my busy career as an artist, I have still found time to work on personal projects. Fluid simulations are still a favorite, especially the ink in water effect.
The payoff of waiting days for a simulation and render can be very rewarding if it all comes together well. I also enjoy pushing the technological boundaries of the art form. I am fortunate enough to have a decent home workstation, but as anyone in visual effects and especially simulation work will tell you, there is no such thing as a fast enough computer. You will always end up waiting at some point. This can be a great thing if you have free time at work waiting on simulations, but not so much if you only have a small amount of free time while working on a demanding project. This is just one reason why cloud rendering is so interesting - you can speed up your workflow by days. Any type of fluid simulation and render is a great application for cloud rendering as the machine requirements can be quite steep. I have found ink simulations are a great candidate for this type of workflow.
To create an interesting ink in water effect you need a few elements to come together to make a pleasing end product. First, you need a fluid simulation. This is done using volumes to set up your base motion and the overall look, speed, and timing of the effect.
Pictured below is a fluid simulation that helped to drive one of the ink simulations.
I usually start with a pyro sim in Houdini. The dry ice shelf is another good starting point. What is nice about using the dry ice preset is that the density source already has a negative temperature value to make the smoke fall. One could also simply start with the billowy smoke preset and change either the source to have a temperature of -1, or change the buoyancy direction to be -1 on the Y axis. A ‘medium’ resolution volume (probably around 20 million voxels) should be sufficient as it will not be rendered in the end, but used to drive, or more specifically, advect the particles. Once the volume is behaving in the desired way it’s time to simulate millions and millions of particles.
Pictured is the workflow for driving the particle motion from our earlier simulated volume.
I’m typically using over 100 million particles for renders with lots of details. I think the farthest I’ve gone is around half a billion particles for any single frame. Working with such a high number of particles can make for slower iterations. A good way to prototype faster is to start with a small number of particles and make sure the look and behavior is correct. I would also recommend starting out using the update position mode on the pop advect node, as shown in the screenshot above. I want to thank SideFX again for all of the improvements they have made especially to pops and multi-threading. In the past couple of Houdini versions this type of effect is much easier and quicker to produce using the updated particle advection node.
Pictured below is the finished point cache. Here I added some tweaks after the simulation to change the ink’s color as well as pscale for rendering.
As you can imagine, heavy simulations like this can be very intensive on a computer’s CPU, RAM, and disk usage. A single simulation can easily take up a few hundred gigabytes. I will often cache my simulations out to a specific directory or even whole drive to maintain better performance and make cleanup faster between iterations. Finally, once all simulation steps are complete, it’s time to light, render, and composite the effect.
Tips and tricks to find time for personal projects
As a busy commercial artist, my time is one of my most valuable assets. It can be really difficult to find the time to work on personal or other side projects. Because of this I demand a fast and efficient workflow. I have found that using GridMarkets cloud rendering helps to free up some of that time. I’m more focused on the art - I don’t have to worry about farms and servers or how I’m going to fit another half terabyte simulation on my computer. I can simply submit and get a result back in a couple hours, even if it is a heavy simulation job. That can be a real benefit to for work / life balance and help keep me in a creative mindset as there are now less technical and time related restraints to produce high quality work.
I have also found that collaborating with other artists can also inspire creativity and bring everyone’s work to new heights. Too many times I have gotten stuck on one single aspect of a project or a concept. Bouncing ideas off one another or troubleshooting with another artist can yield elegant and creative solutions. This is often the case working with colleagues at the studio and it has the same benefits when working on passion projects.
Lastly, never stop learning. It can be a little intimidating just how vast a field visual effects and 3D in general is. It involves computer science, engineering, and art. The combination of these disciplines requires a lot of time investment and is always evolving at the pace of our collective technology, tools, and techniques. I’m always amazed at how other artists’ have solved problems and come up with really elegant solutions, so it’s a good idea to follow some of their tutorials and forum posts. Learning more about the math behind computer graphics can also boost your potential when working in a technical field such as FX. Even computer engineering and programming will help one’s ability to produce cutting edge work, as so many concepts build on one another. In my own experience I have found linear algebra, python, vex, computer networking, and system administration to all improve my art as well as my quality of life.
Phill Mayer 2016
By: Patricia Cornet