Tutorial

Compositing CGI into live-action footage

A shot-by-shot method for matching a CGI element to filmed footage, from camera and contact to grain, blur and the final viewing transform.

DELA Media2026-10-27

Cinema camera rig and studio lights positioned for a live-action shoot.

A CGI element belongs in filmed footage when its camera, light and image characteristics agree with the plate. Work through those relationships in order. Polishing a material before the camera or contact is convincing usually makes the underlying mismatch harder to diagnose.

Lock the plate and its interpretation

Start with the agreed footage, frame rate, frame range and any retiming. Record the crop and delivery frame before solving the camera or preparing an insert. If the plate changes later, a track that was correct for one version may no longer be correct for the edit.

Keep a reference copy of the untouched plate. Distinguish the source interpretation from the creative grade so that a contrast adjustment does not become an unexplained change in the technical pipeline. Establish how the CGI render and the footage will be viewed together before trying to match their colours by eye.

Solve perspective before polishing the surface

Place a simple test object into the shot. Choose something whose scale and contact are easy to judge, such as a neutral box resting on a visible surface. Watch the whole move. If the box slides, changes apparent scale incorrectly or fails to stay aligned with the surface, resolve that problem before adding detailed materials.

A moving camera, a moving object and a flat tracked insert are different tasks. A corner-pinned graphic can follow a plane, but it does not reconstruct the whole space around that plane. Choose the tracking method for the geometry the viewer needs to believe.

Adobe's tracking documentation is a useful reference for that distinction and for transferring tracked motion. It is not a claim that every shot can be solved automatically.

Make light, contact and occlusion agree

Identify the strongest light direction in the plate, then inspect softness, contrast and reflected surroundings. Use nearby real objects as evidence. An inserted product should not have a broad soft shadow if neighbouring objects have a small hard one unless there is a deliberate reason.

Check the contact point and the objects that pass in front. A plausible render can still look detached if its base does not sit on the surface or if a foreground edge fails to cover it. Test those relationships with simple shading before spending time on a final beauty pass.

For an illustrative countertop shot, separate three questions: does the product stay fixed to the counter, does its shadow meet its base, and does a passing hand correctly overlap it? Solving them separately makes feedback more precise.

Match the image characteristics

Compare the insert and the plate at the same viewing size. Check edge sharpness, depth-of-field cues, movement blur and texture. An unusually crisp CGI object can appear pasted onto a soft plate; excessive blur can hide the error in one frame while creating a new problem in motion.

Add finishing texture deliberately rather than using grain as a general disguise. Inspect smooth areas and dark edges where a mismatch is easy to see. Check alpha boundaries against both light and dark parts of the plate, especially when the image will be compressed.

Blender Studio's Charge poster article shows independently rendered elements assembled into one composition. It is a still-image example, so it illustrates element separation rather than proving a moving shot's track.

Review in an order that identifies the cause

Use a rough composite to approve geometry and timing, then refine lighting, surfaces and finish. When something looks wrong, return to the earliest unresolved relationship. A colour adjustment should not be used to compensate for the wrong perspective.

Review this sequence:
1. Full-speed playback for sliding or implausible movement.
2. Representative frames for perspective, contact and occlusion.
3. Close inspection of edges and highlights.
4. Final-size playback after grading and export.

If the shot only looks convincing when paused at its strongest frame, it is not ready. The acceptance target is a coherent sequence in its intended viewing context, with any deliberate stylisation clearly understood.

Sources and visual references