As a Resolve colorist and Flame/Fusion VFX artist, I’ve done my fair share of VFX compositing, rotoscoping, keying, object removal, tracking, and basically any other VFX process you can think of. I’ve also managed shots that had to be sent out to vendors all over the world, and wrangled pipelines of major commercials and features.
In all that time, I’ve learned firsthand the ins and outs of different types of VFX workflows, and truly appreciate how difficult it is to build one from the ground up.
But I’ve also come to realize that VFX pipelines aren’t something to be scared of. Once we understand the fundamental components and how they fit together, it’s fairly easy to build new workflows that fit our particular creative needs and technical resources.
In today’s article, I’ll lay out several best practices for VFX workflows. We’ll cover the basics of building your own VFX workflow from top to bottom, and help answer questions on everything from hardware and software choices, to setting up proper color management, folder structures, and file naming conventions for your project.
Many of these recommendations are tailored to smaller teams handling 2D compositing-type effects, but most of the principles will apply to large 3D/CG as well. So there’s something here for everyone interested in VFX workflows.
Let’s dive in.
Contents
A little background
In the old days (pre-digital acquisition), film negatives had to be scanned before any sort of VFX could be added to a scene.
This conversion process from an analog, physical, chemically-processed medium to a digital video/image file requires complex processes to ensure all the captured dynamic range, color, and detail of a shot remains intact for VFX teams.
The scanning process was (and still is for film-based workflows) a key factor in preserving the highest visual quality from the camera negative.
Lots of really smart people poured buckets of money and time into developing and optimizing the best methods for scanning film. The better the scan, the better the canvas for VFX teams to work their magic.
Thankfully, we now enjoy the benefit of inexpensive, ultra-high-quality digital cameras. The files that come off digital cameras usually have everything we need to work on proper VFX.
That said, even though we don’t “have” to scan film anymore (although many high-end productions still elect to shoot on film), the analog to digital process is still a major consideration for VFX workflows. Except now instead of it happening in a lab somewhere, it happens right behind the lens.
Analog scenes, digital files
Like film scanners, digital camera sensors capture analog information (the light data entering the lens) and convert and encode it into digital files. Though, sometimes the camera only stores the raw light data (that’s what a raw file is).
Let’s imagine you’re planning a shoot for a VFX-heavy scene. What is the optimal capture format? Well, it depends, but let’s start with the basic question—should you capture raw or RGB?
While it’s true that raw formats preserve unrivaled levels of image detail, they can be problematic for VFX. That’s because many raw formats capture videos into multiple files (one file per frame for some formats), rather than a single convenient file that wraps all the frames together.
Obviously, this can cause issues for VFX teams who have to pass files between multiple users/machines/departments/facilities. Adding hundreds or thousands of individual files per shot to the process can be confusing, not to mention time consuming, since raw files are quite large.
On top of that, the nature of raw footage would require every user to re-encode and debayer the raw files in order to work with them. That just slows down the process further and increases the risk for errors.
So, while capturing in a raw format is generally a good idea and will deliver the highest-quality image for your project, you’ll probably want to convert the footage to another working format before it reaches your VFX workflow.
But let’s say you want to keep things simple, and you don’t want to bother with re-encoding the raw files. To save time, you choose to shoot your scene in a log format. They’re pretty good at capturing dynamic range, and with a 10-bit encode they leave lots of room for image manipulation during post-production.
Log files are a lot easier to work with in your post pipeline because you won’t have to do any of the crazy raw workflow gymnastics just to pass the files around. But they can make some VFX processes more difficult, like certain types of keying or compositing.
If raw and log are both problematic, what capture formats and types of files make the most sense for VFX work? How do you effectively preserve the highest-quality image from a camera sensor all the way through post, while also choosing a format that won’t slow you down or make your work difficult?
There are many potential answers to these questions. Ultimately, the right answer for you depends on the project and the type of VFX you need and the resources available.
And since most of the time your resources will be tied to the sort of work you’re doing, let’s take a look at the most common types of VFX.
Types of VFX work
When most people think of VFX compositing, they think of explosive superheroes, fantastical CGI worlds, or epic action sequences. Work like that is usually only possible with huge teams responsible for individual sequences.
The workflows for these shots are planned far in advance by VFX supervisors and team leads. They decide the file types, working color spaces, folder structures, and naming conventions during pre-production.
While this type of VFX work for major blockbusters is what most people think of when they hear VFX, it’s only one facet of the larger world of VFX work.
In commercial work, for example, VFX can be much more subtle, like removing a reflection from a car, painting out a blemish on skin, or shrinking someone’s waistline. Here, the idea is to keep the effects mostly invisible.
Small teams are quite capable of this type of VFX, but their workflow will look much different than that of a larger project. For commercial work, a team might be working on four entirely different jobs that use completely different cameras, all at the same time.
That means the VFX workflow will have to be flexible enough to handle many different capture formats, and may not benefit from the same degree of pre-planning that the large workflows have.
Needless to say, this necessary flexibility can make project organization and shot management less predictable than on feature work. And many small teams won’t have a dedicated post supervisor or engineer behind them to keep the project rolling when technical issues pop up. In some cases, individual artists might be in charge of building and maintaining their own workflow.
Without that kind of support, VFX work can get really complicated really quickly. Balancing the technical demands of the workflow with the creative tasks of the project can become challenging.
It can be difficult to make these types of workflow decisions if you’re building a new VFX pipeline, since there are so many factors to consider. So let’s take a step back and demystify the overarching process and considerations. That way we’ll get the most out of our tools and have a better understanding of their capabilities.
Considerations for VFX Workflows
There are a few major things to consider when deciding on an appropriate workflow for a project. And these considerations are all interdependent on each other. That means that if you have to change one, you’ll likely have to adjust the rest of the process.
For example, your color pipeline could be dependent on which piece of software you use. And the piece of software you need will influence the hardware you choose. That hardware might impact which file types/formats you can use efficiently. And so on.
It’s important to look at each of these workflow categories with the big picture in mind.
Here are the major considerations you need to consider when building a VFX workflow:
- Color management
- File format
- Resolution and bit-depth
- Software
- Hardware
- Naming conventions and folder structure
- Budget and time
While not required in every instance, I find it helpful to think about these decisions in this order. It makes it easy to see what choices are dependent upon the other.
Color Management
Before deciding on any workflow, color management of the project is probably the most important factor. Why? Because making sure the image data is displayed, transformed, and stored correctly will make or break the VFX.
There are two major approaches to color management for VFX: scene-referred and display-referred. There’s a lot to unpack with these workflows, but I’ll quickly review the basics here.
Scene-referred data reflects the light values of the real-world scene as it was captured, instead of a conforming that data to particular color space.
Display-referred data, on the other hand, encodes the sensor information to a target color space, and applies a gamma curve to the image file.
Scene-referred
If you’ve ever shot raw footage, you’ve dabbled in a scene-referred format. With this type of workflow, you have to convert the linear light values into a displayable format every time you want to work with them.
A lot of major feature films or high-end projects use linear light workflows, so as you can imagine there are a lot of moving pieces.
For example, if you were compositing a shot in a linear light workflow, you’d have to convert the shot for viewing with a display lut or output transform to do any work. Then, once you finished compositing the VFX, you’d have to render the files back into linear light (remove the display transform) in order to preserve the linear light values.
This approach makes many aspects of compositing better, like blending, because the math running behind the scenes is much more precise.
Linear workflows also make delivering to multiple formats easier. Since no gamma curve or color space is automatically assigned to the image data, you can render to any delivery color space you want (or just keep them in a linear light format for archival purposes).
As newer, better display formats are developed, you could take these same renders and convert them into those newer display formats to take advantage of wider color spaces and increased dynamic range for HDR standards.
But these benefits come at a cost. Transforming between color spaces, keeping files organized, and making sure all the metadata survives as files are passed down the pipeline can feel like a full-time job (and in many workflows, it literally is). That’s why with a smaller team or project, a scene-referred workflow might be overkill.
Display-referred
For less complicated workflows, like commercial, corporate, and even television workflows, display-referred workflows are often the common choice.
If a show or commercial is only going to be broadcast, or be streamed online, then you only need to cater to one delivery format. That means you can save a lot of time by working in that delivery color space.
With display-referred workflows, files aren’t converted when they’re imported. The project’s color space will probably just be the color space the camera encoded the files to, and VFX are made to match this display output. You only need to render scenes to this associated color space.
But of course this simplicity sacrifices flexibility. Once you decide on a mastering format, that’s it. All your files will be bound to that color space. This may not be an issue if you don’t need to deliver multiple color spaces or delivery destinations, so the weight of this decision will depend on the demands and expectations of the project.
File Formats
Once you have your color management figured out, choosing a file format is a relatively easy decision, but it’s still important.
It’s critical to understand the limitations and strengths for any potential file formats before you start using them in your workflow. One of the most important factors when choosing a file format is how the data is stored within that particular format.
There are two main methods for storing digital data: integer and floating point. These may sound complicated, but stick with me.
Integer data means that data like RGB values won’t contain decimals. They are represented by whole values (no decimal places) within a predetermined range.
Floating point data, in contrast, stores decimal places and can encode values beyond the set range.
What are the benefits of each approach?
In general, floating point values yield better results for VFX. Since there are more numbers available to calculate, the conversion between various color spaces and compositing operations is more accurate. This makes floating point files more desirable in a scene-referred type workflow.
Integer files, by contrast, aren’t as accurate when going back and forth to linear from log or other transforms, because rounding errors stack up. Since numbers can only be integers, estimations are made in each conversion, which leads to inconsistency and artefacts. That said, single conversions to a display color space are common with integer formats, and so they work fine within a display-referred workflow.
To compare the two more directly, floating point type files are great for compositing work. But for color grading, integer files tend to work better, since most grading applications still run best with log encoded integer data.
That’s why if your project has a lot of CG integration work, OpenEXR files may be the best file format to use. Since OpenEXRs can store scene linear data, you’ll maintain all the benefits of that workflow, as we discussed earlier.
But if the VFX needs for a project are more invisible, like scene cleanup and objects removal for broadcast work, an integer-based format like log DPX or ProRes444 will work just fine. Log-based or display-referred workflows simplify the process considerably, since those color transforms are well defined and less complicated than scene-linear transforms.
Resolution, Bit-Depth, and Compression
The next important consideration for your workflow is the resolution and bit-depth of your shots.
In most workflows, there is a compromise between source resolution and deliverable resolution. Some modern cinema cameras can shoot up to 8K resolution, so your plates can theoretically be that large, but 8K VFX plates would slow down VFX work to a crawl.
However, if editorial is going to use a lot of push-ins, or your deliverable format is 4K, then 1080P will be way too small.
Bit-depth is also an important consideration. If you’re heavily manipulating color, you’ll need access to a large range of digital values. For integer work, 10-bit is the standard, but for floating point, 16-bit float is usually the best choice.
Finally, compression also plays a major role for VFX pipelines.
When making VFX plates and renders, for example, the compression method used will dictate what blends together or stands in the scene. If the compression used on the plate doesn’t match what was used on the composited elements, the visual continuity of the shot will likely be broken.
For my recommendations above, OpenEXR files offer flexible compression options to match between elements, and can be optimized to save drive space and hardware load. But ProRes444 is much more compressed than DPX files, which will speed things up at the cost of lossless quality. QuickTimes are not commonly used in higher end VFX workflows for several reasons, but if drive space and hardware are a concern, they can work.
For projects with quicker turnarounds or lower budgets, keeping file sizes smaller and bit-depths low (10-bits minimum) will speed up workflow. The most suitable choices will depend on your project.
Of course, you’ll need to know how your files will be used upstream to decide on resolution, bit-depth, and compression. Picking a happy medium between the lossless quality and usability/speed is generally the best option, but finding that sweet spot will be dependent on your hardware and software capabilities.
Software
There are more options than ever for VFX work these days, but I’m going to focus on the three most common applications for compositing work:
- Nuke
- Flame
- After Effects
Nuke works in scene-referred space by default. If Nuke is the software of choice for your teams, then OpenEXR files will be the best choice. In fact, we can all thank Nuke for scene linear workflows, OpenEXR files, and floating point formats. These technologies were less popular prior to the advent of Nuke.
If Flame is your preferred workbench, note that it too can utilize scene-referred data. That said, Flame is traditionally more commonly used in broadcast situations, which are obviously display-referred. Using a scene-referred workflow with Flame is a bit more complicated than with Nuke, as DPX files are the common choice in Flame workflows.
When it comes to After Effects, things can get tricky. Color management in After Effects is more difficult to line up, especially since After Effects is layered-based (rather than node-based). Piping input transforms and output transforms for scene-referred workflows is difficult.
That’s why, typically, After Effects work isn’t scene linear, and the most common file formats are QuickTimes and image sequences like .tiff, targas, or .pngs (usually in integer flavors, though floating point is an option).
Because larger budget projects usually call for the highest quality (i.e. scene-referred) workflow, Nuke is the first choice for most large productions. But medium and small projects can leverage the power and speed of Flame and After Effects for incredible VFX, especially if all they need is display-referred outputs.
Hardware
Hardware is the next consideration when building a VFX workflow.
High quality files generally take up more space, and require more processing power. Many of you will be intimately familiar with hardware bottlenecks, and sadly there really isn’t a way to get around them other than upgrading to a more powerful system.
In particular for VFX pipelines, the image files we use most often, like OpenEXR sequences, are taxing and take up tons of storage.
That said, if your work doesn’t require the highest end workstations, then you can build a very efficient pipeline without breaking the bank. In fact, spending extra money for hardware (like more storage than you need or processing power that goes unutilized) will do you more harm than good.
Thankfully, systems keep getting faster and cheaper, and it’s easier than ever to scale your compute and storage resources as your business grows.
Naming Conventions and Folder Structure
Naming conventions and folder structure are an integral part of any VFX workflow. Every single asset in your pipeline will need a carefully thought out name and place to live, from plates to renders and everything in between. If you skip this step, you’re setting yourself up for a world of pain and suffering.
File Names
It can be difficult to decide what information to include in a file name, what type of metadata to embed, and where to put the files. In my experience, the most important information to include in a VFX shot is the shot number, unique shot name, version number, and embedded timecode.
I also think shot numbers are a must for VFX shots, as they can be tracked in a workflow tracker or database. This makes it easy to check their status, and keep up with vendors.
Whatever you choose, organization and consistency are key, especially with larger teams. If even just a few assets are mislabeled or put out of place, your workflow can come to a screeching halt.
Folder Structure
VFX work involves a lot of moving files around. Plates are rendered out from OCNs, they’re imported into a scene, and then composited scenes are rendered out. It’s important to decide upfront where source plates and rendered composites (and the many other types of assets VFX generates) will live.
Again, shot numbers are a necessity. Shot numbers keep plates, graphics, and all associated elements of a VFX shot together and organized.
In my experience, dated folders (like you might have for OCNs) are confusing for VFX shots, especially with complicated projects. Shot numbered folders, on the other hand, make a lot more sense, especially if version numbers are added to further eliminate the need for dates.
Project Needs
You’ll need to assess the needs for your particular project when deciding on folder structure and naming convention. It’s important to balance how much information should be included in the file name with how easy these file names are to read/use.
If you’re using shared storage/servers, shared media, and multiple artists, it’s absolutely critical that everyone has buy-in on the naming convention, and maintains consistency for the duration of the project (and every project). This can be a challenge during the rush to finish, but it’s the only way to keep your workflow from falling apart.
In some cases, different departments might have their own servers and file naming conventions, and they may pass off finished composites/elements to the next team department who might also have their own storage and file naming practices. But for environments with any sort of centralized asset management, establishing protocols that stretch across your entire organization (and that are followed by vendors) is paramount.
Budget and Time
The single biggest consideration you need to make when building your VFX workflow is the available budget and time.
As a VFX artist, one of the most important skills you can learn is predicting how much time something will take. Each of the considerations we’ve already discussed will determine how much time it will take to finish a VFX shot, and you need to make sure that the process you build aligns with the allotted resources.
A good way to make sure you’ll finish on time and on budget is by testing your workflow before beginning a project. As you test, and gain experience with your pipeline, you’ll get a much better idea of how long certain processes take, which makes calculating time savings or increased burden from pipeline changes easier.
If more complicated projects require scene-linear work, your tests will give you a baseline to calculate the extra work from and figure out how many extra artists and time are required to get it done. Or if a production only needs display-referred renders, and you’re used to scene-referred work, you’ll have an idea of how much faster you can finish the project.
It’s also important to assess the skills of your team. If a job will stretch existing skill sets, you should add more time into the schedule. But if a project has an amazing team lead, it might take that person half the time to do something it would take a junior artist to do.
Speed vs. Quality
Another thing to consider is speed vs. quality. If speed is more important than quality, lower resolutions and compression will save time and no one will notice. Some client budgets don’t always allow for the highest quality workflows, and that’s ok.
But if quality is the most important factor, and client budgets are high (not a common scenario, but we can dream), then it’s time to invest in the personnel and machines to make it happen.
In the real world, compromise between quality and speed is necessary, even at the upper-end of the market. More and more, leaner VFX teams have made inroads to top tier clients, especially as off the shelf software and hardware have become more accessible.
Perhaps counterintuitively, surviving in the market is difficult for larger, more capable teams, because client demands are always evolving, while the prices you can charge clients keep falling. Large workflows require large investments in pipeline, software, and hardware, along with the engineers and personnel to support that investment, but that investment quickly becomes obsolete whether or not it has paid for itself.
Ultimately the most important consideration is whether or not your workflow will help you accomplish the goals of a specific project. The more you plan ahead, the more successful and productive your VFX workflow will be.
Boundaries and flexibility
With that in mind, there’s a specter that will likely hover over your VFX pipeline which you’ll have to face eventually: client boundaries.
As Hollywood has shown us time and again, major VFX projects can produce incredible creative achievements, but lead to the ruin of the team who created it all.
It is absolutely crucial to set expectations and boundaries with clients early on, based on the allotted budget and time frame. If changes are requested during the project, the extra costs incurred must be communicated to the project. Of course, artists and producers should be flexible to make sure the client’s needs are met, but not at the expense of the team’s mental, physical, or financial prosperity.
Too much flexibility and capitulation to client demands can lead to artist burnout and the demise of your business. If it can happen to Oscar-winning teams, it can happen to you.
If client requests start to pile up, it’s crucial to set better boundaries based on the budget. This is why it’s important to take time at the beginning to accurately assess and factor in time for changes or unforeseen hurdles.
Producers and Client Relationships
Client relationships are a huge part of the planning process, as well.
If your client expects you to give them a flat bid, and there isn’t a clear understanding about revisions or additions, you’re setting yourself up for disaster. Establishing mutual respect between the client and your team is essential, and building boundaries will help ensure that respect is maintained.
This is why talented post-production producers or supervisors are so valuable. They can manage clients, track costs, communicate changes to artists or hurdles to clients, and generally keep the projects on task and on budget. Having one of the artists act as a producer can make things difficult, so, if possible, budget money for a producer/project manager into your workflow.
After many years in this business, I know how hard it is to set these boundaries. Getting a shot or a scene just right may take extra hours or days or weeks. But with the right support, healthy lines of communication, and a sharp producer watching your back, VFX work doesn’t need to be painful. It is possible to deliver high quality work in a reasonable time frame within budget. But it takes practice and experience.
Conclusion
VFX workflows are complicated. There are so many factors to consider, and it takes years of experience to accurately estimate time and to work with clients effectively. On top of that, the technical skills of this industry keep evolving at a breakneck pace. But if you think about the steps we just covered, you’ll be well on your way to building a successful VFX team and pipeline.
As you continue to test your workflow and to learn by completing projects, you’ll better understand how to plan and budget, and learn the complex dance of client interaction.
Successful VFX teams need to communicate, encourage one another, and all push in the same direction to move a project over the line. I hope you found this overview useful and wish you the very best of luck on your journey into the world of VFX!
