VFX Glossary
Whether you’re new to visual effects or looking to learn about industry terminology, this glossary covers terms used in VFX compositing. You’ll find clear definitions of the language that shapes our craft.
This resource is designed for anyone curious about the technical side of creating seamless visual effects for film, television, and advertising.
Compositing
Digital compositing is the process of combining multiple visual elements from separate sources into a single image or sequence, creating the illusion that all elements exist in the same scene. This fundamental VFX technique is essential in modern filmmaking, advertising, and content creation.
What is Compositing?
In post-production, a compositor assembles various layers—live-action footage, CGI elements, matte paintings, effects simulations, and color corrections—into a seamless final image. Think of it as digital collage, but with precise control over lighting, color, depth, and movement to ensure photorealistic integration.
The term comes from traditional optical compositing, where physical film elements were combined using optical printers. Today’s digital compositing offers far greater flexibility and creative control.
Key Compositing Techniques
Keying: Extracting subjects filmed against colored backgrounds (green screen, blue screen)
Rotoscoping: Frame-by-frame masking to isolate elements or create mattes
Tracking: Matching the movement of elements to live-action camera moves
Color correction: Adjusting colors to match lighting conditions across all elements
Matte painting integration: Blending digital environments with live-action plates
Industry-Standard Tools
Professional compositors typically work with:
- Nuke (industry standard for film and high-end VFX)
- Flame/Flare (real-time compositing for finishing)
- After Effects (motion graphics and broadcast work)
- Fusion (node-based compositing)
Why Compositing Matters
Good compositing is invisible. When done well, audiences never question whether elements belong together. Poor compositing—mismatched lighting, incorrect grain, color inconsistencies—immediately breaks immersion.
From invisible wire removal to spectacular superhero battles, compositing is the final creative step that brings a director’s vision to life.
Extra information on [Wikipedia →]
Rotoscoping (Roto)
Rotoscoping, commonly called « roto » in the VFX industry, is the technique of creating frame-by-frame masks or mattes to isolate elements within footage. This painstaking but essential process allows compositors to separate subjects from their backgrounds, apply selective adjustments, or prepare elements for integration with CGI.
What is Rotoscoping?
Originally, rotoscoping referred to tracing over live-action footage to create realistic animation. In modern VFX, the term describes the process of drawing animated shapes (splines or bezier curves) that follow the contours of objects, characters, or specific areas within moving footage.
These masks serve multiple purposes: extracting a subject from its background, isolating areas for color correction, creating holdout mattes for CG integration, or removing unwanted elements from a shot.
The Roto Artist’s Process
Initial shape creation
- Analyzing the shot and planning the approach
- Creating the base shapes on a key frame
- Determining the level of precision required
Tracking and animation
- Adjusting shapes frame-by-frame to follow movement
- Managing motion blur and edge softness
- Handling occlusions and perspective changes
Refinement
- Edge feathering for natural integration
- Quality control and consistency checks
- Preparing mattes for compositing handoff
Common Rotoscoping Challenges
Complex movement: Characters in action, with limbs crossing, fabric flowing, or hair moving require meticulous frame-by-frame adjustment.
Motion blur: Fast-moving subjects create blur that must be accurately captured in the matte edge.
Fine details: Hair, fur, transparent elements, or intricate costumes demand extra precision and often specialized techniques.
When Rotoscoping is Used
- Green screen extraction: When keying alone can’t achieve clean edges
- Background replacement: Isolating subjects to place them in different environments
- Selective color grading: Adjusting specific elements without affecting the entire frame
- Object removal: Creating clean plates by masking out unwanted elements
- CG integration: Providing holdout mattes so CG elements correctly pass behind live-action subjects
Tools and Techniques
Professional roto work typically uses:
- Nuke: Industry standard with powerful spline tools and planar tracking
- Silhouette: Specialized roto and paint software with advanced tracking
- Mocha Pro: Excellent planar tracking to reduce manual keyframing
- After Effects: For simpler roto work in motion graphics
Modern tools incorporate machine learning and tracking algorithms to reduce manual work, but human artistry remains essential for quality results.
The Art of Invisible Work
Good rotoscoping is never noticed. It’s one of the most time-intensive aspects of VFX, requiring focus, precision, and an eye for edge quality. While often considered entry-level VFX work, excellent roto artists are highly valued—poor roto can ruin an otherwise perfect composite.
More information on [Wikipedia →]
Color Grading (Grade)
Color grading is the creative process of enhancing and manipulating the color and tonal qualities of moving images to achieve a specific aesthetic, mood, or visual consistency. It’s the final artistic polish that transforms raw footage into a polished, cinematic image.
What is Color Grading?
While color correction fixes technical issues (white balance, exposure), color grading is a creative choice. It’s where a colorist collaborates with the director and cinematographer to establish the visual tone of a project—whether that’s the bleached, desaturated look of a dystopian thriller or the warm, golden tones of a romantic drama.
In VFX, grading serves an additional technical purpose: ensuring that elements, composited layers, and live-action footage all share the same color palette and lighting characteristics.
The Grading Process
Primary corrections
- Balancing exposure, contrast, and white balance across the entire image
- Establishing the baseline look
- Ensuring consistency between shots and scenes
Secondary corrections
- Selective adjustments to specific areas or color ranges
- Isolating skin tones, skies, or other key elements
- Power windows and masks for targeted grading
Creative grading
- Applying the artistic look (film emulation, stylization, mood)
- Matching reference images or establishing visual themes
- Creating cohesion across different shooting conditions
Final polish
- Adding film grain or texture
- Vignettes and subtle enhancements
- Quality control and delivery preparation
Color Grading in VFX Workflows
For compositors, grading knowledge is essential:
Matching elements to live-action: Ensuring 3D renders blend seamlessly by matching color temperature, contrast ratios, and tonal response.
Shot matching: Making different takes or camera angles feel like they belong to the same scene.
Integration grading: Using selective color correction to help composited elements feel embedded in their environment (color spill, atmospheric perspective, light wrap).
LUT management: Working with Look-Up Tables (LUTs) to maintain consistent color pipelines from set to final delivery.
Industry-Standard Tools
Professional grading typically uses:
- DaVinci Resolve: Industry-leading color grading platform
- Baselight: High-end grading for feature films
- Nuke: Node-based grading within the compositing workflow
- Flame/Flare: Integrated finishing and grading suites
Color Spaces and Technical Foundations
Modern grading requires understanding:
- Color spaces
- ACES workflow (Academy Color Encoding System)
- Log formats
Why Grading Matters
Color profoundly affects emotion. The same scene can feel hopeful, melancholic, or menacing depending solely on color choices. In VFX, grading is the bridge between technical accuracy and artistic vision—it’s where realism meets style.
A skilled colorist doesn’t just adjust numbers; they shape how audiences feel about what they’re watching.
More information on [Wikipedia →]