What Is Computer Graphics and How Does It Relate to VFX Compositing?
Computer graphics is the field of generating, manipulating, and displaying visual content with computers. It spans everything from 3D modeling and rendering to 2D image processing and animation. VFX compositing is one specialized part of that field: it takes rendered or photographed layers and combines them into a final image. Node-based compositors like Natron sit in that 2D layer of the pipeline, and they are used after 3D rendering or live-action shooting to assemble the shot.
The Main Subfields of Computer Graphics
Computer graphics is broad enough that "CG" can mean different things depending on who is speaking. In production, it usually breaks down into these areas:
| Subfield | What it covers | Typical output |
|---|---|---|
| Modeling | Building 3D geometry | Characters, props, environments |
| Rendering | Turning 3D scenes into 2D images | Frames with lighting and shading |
| Animation | Defining motion over time | Keyframed or simulated movement |
| Imaging / 2D compositing | Combining, correcting, and finishing image layers | The final shot |
These areas overlap in practice. A single shot may involve a 3D render, a matte painting, live-action plates, and particle elements, all of which need to be merged. That merge is compositing.
Where 2D Compositing Fits in the Pipeline
Compositing is the stage where separate elements become one coherent image. It typically happens near the end of the visual effects pipeline, after modeling, animation, and rendering are done, and it is where the final look is locked.
A compositor's work includes:
- Keying — removing a green or blue screen and refining the resulting matte
- Rotoscoping — drawing mattes around objects frame by frame
- Tracking — matching the motion of a camera or object so elements stay locked to the plate
- Merging — layering rendered CG, practical footage, and 2D elements together
- Color and detail work — matching blacks, whites, grain, and edge quality across layers
Natron's feature set maps directly onto this list. Its page describes "industry-proven chroma keying and matte refinement tools," a "multi-layered rotoscoping toolset with per-vertex feathering," and a "fast, pixel-perfect tracking toolset." It also supports OpenFX (OFX) plugins, the industry-standard plugin format, which means compositors can bring in third-party tools rather than relying only on built-ins.
What Node-Based Compositing Is and Why It Is Used
In a node-based compositor, every operation is a node, and nodes are wired together into a graph. Data flows from one node to the next, so the image you see at the end is the result of a visible chain of steps.
This differs from layer-based editing, where operations are stacked in a timeline or layer panel. The practical difference is inspectability: in a node graph you can see exactly which operation produced which result, and you can branch, reuse, or bypass any part of the chain.
Natron's page frames this as a workflow advantage: "No more hunting through nested pre-comps! Nuke and Fusion users will be right at home with Natron's node-based workflow. Group, merge, and tinker to achieve just about any effect." It also notes that users can "build, group, and save your own node snippets to create and share custom tools and presets," and that community-made PyPlugs (Gizmos) install by drag and drop. That reuse is one of the main reasons node graphs are standard in VFX: a complex setup can be collapsed into a single reusable node.
CGI vs. Compositing: How They Differ in Production
CGI and compositing are often used interchangeably in casual conversation, but they are distinct stages:
- CGI (computer-generated imagery) is content created in 3D software — a rendered creature, a digital set extension, a simulated explosion.
- Compositing is the assembly and finishing of that content alongside everything else in the shot.
A rendered CG element is rarely finished on its own. It usually needs to be integrated: matched to the plate's lighting, given the right amount of grain, and blended at the edges. Compositing is where that integration happens. In many shots, the compositor is the last person to touch the image before it is delivered.
Open-Source Tools in Computer Graphics
Open-source software is common across computer graphics, from modeling and rendering to compositing. Natron is one example: it describes itself as "node-based compositing, backed by the freedom of open-source," and its source code, bug reports, and build guides are available on GitHub.
For a compositor evaluating tools, the practical questions are usually:
- Does it support the plugin formats your pipeline uses? (Natron supports OFX.)
- Can it render on a farm without a GUI? (Natron lists "smooth headless integration with render farms for distributed network rendering.")
- Does it run on your hardware? (Natron lists macOS Intel, Windows 8.1/10/11 64-bit, and x86_64 Linux with X11, glibc 2.17+, and libgcc 4.8+; the latest stable release runs on Apple Silicon via Rosetta 2, with a native alpha build available.)
The latest version listed on the site is 2.5.0, released November 25, 2022. The site does not state pricing, so no assumption about cost should be made from the page alone.
How the Pieces Fit Together
Computer graphics is the umbrella field; rendering, modeling, animation, and imaging are its working parts; compositing is the 2D stage where those parts are combined into a finished shot. Node-based compositors like Natron are built for that stage, and their graph structure exists to make complex, reusable, inspectable image operations manageable. If you are learning the field, understanding where compositing sits — after rendering, before delivery — is what makes the rest of the pipeline make sense.