Render

Tab: Render — Movie Render Queue · Plugin: Cinematic Lab

Cinematic Lab does not render. Epic’s Movie Render Queue does. This tab configures it, feeds it shots with their captured Looks, and checks your setup before you commit GPU hours to a mistake.

The Render tab: preset, burn-ins, OCIO, queue actions, dailies and the render-pass selector.

The preflight banner

Read it first. It sits above the queue actions and reports what will go wrong before it does. Items are graded BLOCKER, WARNING or INFO, and it says “Preflight: nothing to report” when there is genuinely nothing.

What it checks, and what each item means:

Severity	Condition	Why it matters
BLOCKER	No render passes selected	The render would produce a beauty-only EXR
BLOCKER	Object Ids selected but Epic’s Movie Render Queue Additional Render Passes plugin is off	Without it the render silently produces no matte layers
WARNING	Alpha propagation off	The render will be fully opaque. The fix text differs by engine — on 5.4 the console variable is read-only, so it names the project setting and says no plugin can set it for you. It also notes that sky atmosphere and fog force alpha opaque regardless
INFO	UE 5.4 high-precision output	On 5.4 precision is a single switch covering every AOV, so all passes in the job are written 32-bit and files are larger than on 5.5+
INFO	Lossy EXR compression with data passes present	Compression is forced to ZIP for the render, because EXR compression applies to the whole file, not per layer
INFO	UE 5.4 holdout	Primitive Holdout is Path-Tracer-only on 5.4; use Object Id mattes to isolate objects in a deferred render
INFO	Object Ids selected	It is an Epic beta pass: translucent objects flatten to an opaque layer, and it does not support screen percentage

Every one of these is a silent failure mode somewhere else in the industry. Here they are stated before the render starts.

Presets and burn-ins

Render Preset picks the Movie Render Queue configuration.

Burn-ins overlay frame number, timecode, date and job name onto every rendered frame. Great for dailies and review; leave off for final delivery. Skipped for the EXR Multilayer preset.

Use EQLabs metadata layout swaps the stock frame-info burn-in for a cross-tab layout carrying shot name, status, render version, artist, camera, preset and project. It needs the EQLabs burn-in Widget Blueprint, and the control says what happens without it: it falls back to the stock burn-in until that widget is authored. No silent blank.

Choosing a render preset, burn-ins, OCIO and render passes before queuing.

OCIO colour

Enable OCIO on render output applies an OpenColorIO display transform to MRQ output. Set Source colour space, Dest display and Dest view — the names must match your config.

Sync active viewport to OCIO applies the same transform to the editor viewport so what you see matches what you render. Re-toggle after switching viewports.

Check OCIO Parity

The interesting one. It samples the active viewport, compares it against a reference render frame you pick, and reports the mean CIE ΔE:

OCIO parity: mean deltaE <mean> (max <max>) - PASS | WARN (> 2.0)

That is a measurement, not an assertion — it tells you whether your OCIO render actually matches your viewport, with a threshold you can argue with. Failure modes are reported specifically: no active viewport, could not read the viewport pixels, could not load or decode the reference image.

Movie Render Graph (beta) renders queued jobs through a Movie Render Graph asset instead of the EQLabs preset config, falling back to the preset when no graph is assigned.

Queue actions

Action	What it does
➕ Add Active Sequence	Add the currently-open Level Sequence with the chosen preset
🎯 Add Pending Shot	Add the shot stashed by Render this shot only in Shot Manager
🪟 Open Movie Render Queue Tab	Epic’s own MRQ window
▶ Start Queue Render	Kick the queue off using the PIE executor

Status while running: ● Rendering — <done>/<total> done · current: <job>.

The render queue with jobs added.

Per-shot look renders

This is where the Shot Manager’s Look State pays off.

• Render Pending Shot with its Look. Restores the pending shot’s captured Look State (lighting,. Mirage style, virtual camera), then renders only that shot. This clears the current render queue, and the button says so.
• Render All Shots (each with its Look). Renders every non-Hold shot in the active sequence. one after another, restoring each shot’s Look before its render. Files are named {Shot}_{Status}_v{Version}. One render pass per shot, so it takes a while — stated on the control, not discovered afterwards.

Dailies

Render Dailies (all shots, low-res + burn-ins) is a one-click review pass:

1. Every non-Hold shot rendered with its Look at the Animatic preset, burn-ins on, into Dailies/<date>/
2. Each shot encoded to H.264 mp4 via the Recording tab’s ffmpeg.
3. A ContactSheet.png of first frames written.

Watermark stamps review text — e.g. CONFIDENTIAL - Client X — into the burn-in metadata for every render, drawn centred at low opacity. It needs burn-ins on and the EQLabs layout selected; leave it empty for none.

Render Passes: multi-layer EXR for Nuke

The AOV feature. Passes are grouped by what a compositor actually needs:

Group	Meaning
Core	”a compositor cannot work without these”
Utility	Supporting data passes
Material channels	Per-channel material output
Reference views	”expensive; not additive” — Unlit, LightingOnly, ReflectionsOnly and friends
Object ids	Cryptomatte-style mattes

Two-job render (full-quality Beauty + 1-spp Utility) splits the render into two MRQ jobs. Data passes gain nothing from accumulation, so the utility job drops to one spatial and one temporal sample — the split is routable because each pass declares in data whether it needs high precision and whether it must not multisample, rather than being sorted by a hand-maintained list.

Add Multi-Pass Render to Queue queues it. Build Pass Verification Level constructs a level for checking the passes.

The render pass selector with passes grouped by role.

EXR handling

Output is multi-layer. If any enabled pass requires high precision and the chosen compression is lossy, compression is forced to ZIP — because EXR compression is per file, not per layer, so one lossy setting would corrupt depth and motion for the whole frame.

Encodings are documented, not measured, and the tool says so

Every pass carries an encoding note for the compositor and a bEncodingVerified flag. That flag is false for every pass, and each tooltip appends:

[Encoding NOT yet verified against a rendered frame.]

The shipped Docs/RenderPasses_Encoding_Spec.md defines exactly what “verified” would mean:

Someone rendered a frame in a real project, sampled the pixel values, and confirmed the units and range match what this document claims.

Nobody has done that yet. What is established is where each pass comes from and what Epic’s material emits — a strong prior, not a measurement. As the spec puts it, a depth pass that is silently in the wrong units looks completely plausible right up until a compositor builds a shot on it.

The preflight’s “unverified encodings” count deliberately covers only post-process-material passes — the ones whose pixel values a compositor reads as data. Reference views and Cryptomatte have no numeric encoding to measure, so counting them would inflate a number you are meant to act on.

Layer names

Layer naming differs by engine version, and you should never hand-write it:

Engine	A depth pass lands as
5.4	FinalImageMovieRenderQueue_WorldDepth
5.5+	FinalImageDepth

FEQLabsRenderPassAdapter::PredictLayerNames() is the single source of truth, and both the Nuke generator and the JSON manifest consume it — so they cannot drift from what the engine actually writes.

Notes

• Read the preflight. Two of its items are BLOCKERs precisely because the corresponding failure is silent.
• The parity check is a real measurement. ΔE against a reference frame, with a stated threshold.
• Encoding claims are labelled unverified everywhere they appear — the manifest, the tooltips and the shipped spec. Treat them as a strong prior until you measure them yourself; §4 of the shipped spec is the procedure.