Kevin Pinga, an experienced FX artist with many large projects under his belt, gave 8 useful tips for VFX artists working in the industry.
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Through the rise in demand for effects in television, commercials, and music videos, it seems like a very lucrative time to be a Houdini FX Artist. On the flip side, turnaround times are getting much shorter with quality expectations stepping up to be on par to effects seen in feature films. The reliance on visual effects in most TV shows with such tight deadlines can put pressure on the artist to make sure a shot makes it to final before it is aired, which in most cases are only days (sometimes hours!) away.
I’ve worked on numerous TV shows in the past 3 years of being an FX artist in Los Angeles, including Brooklyn Nine-Nine, The Walking Dead, and the last season of Castle Rock. Additionally, I’ve also done FX work for music videos for artists such as Taylor Swift, Shawn Mendes, and Eminem.
In the time that I spent on these projects, I’ve picked up some approaches that help me deliver high-quality FX in the timeline that was intended.
1. Always Be on Top of Your Scene File
This may sound like very elementary advice, but I’ve seen many good artists go from having manageable scene files to having a chaotic mess due to the pressure of a short deadline (guilty myself!). Unlike in film production, there usually isn’t a lot of time to perform R&D work. The little time allocated for developing a setup usually rolls directly into deploying them into shots, which almost always means sharing the setup with other artists.
It’s easy to find yourself in a position where you have to handoff a setup that’s not organized if you’re not consistently conscious about your scene file and keep it manageable. Artists end up spending more time trying to figure out setups instead of actually working on shots.
Here are some tips to keep your scene files organize:
- Short but descript naming of nodes
- Use netboxes and color/shape codes to organize groups of nodes based on their functions
- Comment out code in wrangles
- Use sticky notes throughout the scene
- Collapse nodes into subnets and promote parameters instead of hiding changes deep inside networks
- Use a Null to add a master control for frequently used parameters
2. Optimizing Caches
One of the challenges of being an FX artist is dealing with heavy geometry. This includes handling data from high-resolution volumetrics, particle count that goes into the hundreds of millions and instancing with complicated geometry. Having optimized caches offers better overall performance which allows you to read your data more efficiently and perform iterations quicker.
Some practices to keep your caches manageable:
- Thrashing attributes and groups that you don’t need before caching
- Culling unnecessary points/geometry that is not within the camera’s frustum
- With volumetrics, delete or down res volumes that don’t contribute to your renders
Additionally, if you have geometry that is ready to be rendered, it is a good idea to cache that out and have the "Delay Load Geometry" checkbox turned on. Instead of having Mantra embed the geometry in the IFD file, it will instead be referenced to the file on disk instead. This drastically reduces your IFD generation times and file size which helps reduce the load on the render farm.
3. Keep Your Sim/Render Times Under Control
According to Jonas Rivera, the producer of Toy Story 4, it took anywhere from 60 – 160 hours to render a single frame (source). In TV, that amount of time could sometimes be allocated to work on an entire shot, oh the luxury!
Personally, when it comes to simulations, I try to keep it under 24 hours when developing a setup (around 4 – 12 hours on average). This ensures that on the next day, I can come to something I can look at to discuss for feedback. If they do go above that, I reduce my sim resolution and run a post-simulation “hack” to have it look higher res (see next tip).
With rendering, there’s always a reasonable compromise for speed over quality. Additionally, breaking up a single beauty render into separate elements (using the matte and phantom options in Mantra) can also speed up render times especially when dealing with shaders that require a lot of ray-tracing power (e.g. an explosion and the rigid body around it, or an ocean mesh with whitewater on top of it).
Of course, this is all relative to the length, complexity, and requirements of the shot. Always keep your supervisor and/or show producer informed if you find your sim/render times are taking longer than expected.
4. Post Simulation Tweaks
With film, the output from a very high-resolution simulation is usually used as a final render. While this is the most ideal workflow, you don't always have the luxury of running simulations that are too high in resolution when it comes to TV. In cases like these, running post tweaks on medium resolution simulations to get it to look higher is common.
Sometimes, when having to address last minutes notes, time is just not on your side and re-simulating isn’t an option. In this instance, running post-simulation tweaks on the original sim can help "salvage" the sim.
For example, with Pyro simulations that require sharper detail, I run a post-simulation up-res workflow. When dealing with FLIP or POP simulations, running a “fill gaps” or point replicate hack can help increase the detail on the original simulation.
5. Stop Caching on Your Local Box! Also, Wedges!
This is something that I’ve observed with many junior FX artists. My general rule is if it takes more than 5 minutes to cache locally, send it to the farm! Chances are, you’re not working on just one element or a shot. Sending caches to the farm frees up your CPU and memory usage allowing you to focus on another shot or another aspect of your element.
Additionally, running wedges on your simulations can also help save a lot of time when tinkering around with parameters. Let’s be honest, we’ve all been in situations where we blindly change parameters to get a simulation look right. Set up a wedge and let the farm crunch out those changes for you!
This is extremely helpful especially in the early stages of development. Most studios are equipped with pipelines that can handle complex wedges.
6. Make Use of Dependencies
Dependencies are possibly one of the most important things to ensure simulations and renders get pushed out on time. Most simulations in FX usually require multiple steps to be run before actually running the simulation itself. Here are a few instances:
- Caching out a high-resolution source before pushing it into a sim
- Running a post-simulation step such as meshing a FLIP fluid
- Running a secondary simulation after the main simulation, such as running an ember sim on top of a Pyro sim
Dependencies allow for automatic start/release of the tasks once a pre-requisite task is finished. In cases like these, I like to keep an organized ROP network that fetches these different caches in the right order. This is also a great way for other artists to figure out the flow of your scene file. You can also end the chain with a render node to ensure your caches get rendered automatically. If your network is set up correctly, you can quickly run changes before you leave for the day, and ensure all the steps are run throughout the night on the farm.
Again, most pipelines are also equipped with pipelines that allow dependencies and wedges at the same time. Great use of this is setting up wedges with a low-resolution render node chained at the end to act as a “playblast” for each wedge. This way, you don’t have to wait to playblast each wedge individually.
7. Assembling Slap Comps
In many cases, complex FX shots usually require the layering of multiple FX elements. Additionally, these elements require more than just the regular “A over B” merging process in Nuke. As an FX artist, you might know how to layer them correctly, but your compositor might not. Without a slap comp, your compositor might blindly assemble your layers and it might not turn out how you intended it to be.
You’ll walk into a review the next day only to find out that your FX elements have been butchered and end up getting notes that are irrelevant to the current state of your elements! Save yourself the trouble and build a slap comp. This informs your compositor of what layers you are using, and how they are intended to be used.
I cannot tell you how many situations there were in which I’ve been able to save myself by saying “But it’s there in my slap comp!”.
Additionally, most FX artists hired by a studio to do TV work are usually expected to shade and light their elements. Let’s face it, we’re not all the best lighters. Doing slap comps can ensure your compositors are aware of all the light AOVs and what you’re doing to dial them in to stay cohesive with the rest of the shot.
8. Keeping an Open Communication with Supervisors/Producers/Compositors
This is less of a Houdini tip, but more of an advice for FX artists in general. With such tight deadlines, there is very little leeway for error which is why it is so important to keep in communication with the rest of the people working with you on a shot.
If you feel like you are unable to deliver a shot on time or have trouble with achieving a specific effect, speak to your supervisor as soon as possible. Just because you cannot deliver something, it doesn’t make you a bad artist. But not letting your higher-ups know about it sooner makes you an irresponsible artist! This way, production can act accordingly by either reassigning the task, getting someone to help you with the effect or finding an alternative solution to achieve the effect in comp.
Make sure to alert your producers/coordinators if you think that render/sim times are going to affect your delivery. Keeping them in communication can ensure you get all the resources needed to push your shots to the end, in this case, farm priority or a compromise with the client.
Finally, talk to your compositors. Chances are, they are going to be taking your elements to the finish line. Keep them posted on any changes/caveats in the elements that you’re delivering to them. Hand them your slap comp scripts as a guide on assembling your elements correctly.
With these tips in your toolbox, hopefully, you’ll be able to deliver high-quality FX work while still meeting the tight deadlines.
Kevin Pinga, FX Artist
Kevin Pinga (website) is a Los Angeles based FX artist from Malaysia who’s worked on award-winning television series including Marvel’s Runaways, The Walking Dead, and Brooklyn Nine-Nine. During his time at Luma Pictures, he has also had the chance to work on Marvel’s latest film Spider-Man: Far from Home which has recently won Best VFX at the AACTA. Additional projects include music videos for Maroon Five, Taylor Swift, Billie Eilish, and Shawn Mendes.