Roblox trailer

SK=<path to this skill folder>. The brief this skill was built for: "record it, make it look like I'm playing it, and edit it too." Everything per game lives in <game>/trailer/: shots.json, clips/, out/. The scripts are generic, and every game-specific name (tags, remotes, prompt text, item ids) lives in shots.json.

Ground rules (read first)

• It records the user's real screen. Before recording, tell the user in chat to keep Studio frontmost and uncovered, park the mouse off the game view, and not touch the computer until you say done, and get their OK. Record only the calibrated viewport region. Delete test and stray takes with record.py clean. Never use -C (cursor).
• Studio etiquette: use one Studio MCP server for this (written against the community robloxstudio server, not the built-in Roblox_Studio one). Check that no other agent is using Studio before starting a playtest. Import the kit in edit mode, remove it afterwards, and never save the place with it.
• Honesty: Roblox rejects videos that show features the game doesn't have, enhanced graphics or ad claims. Staging which real outcome happens on camera (forcing odds for a take, granting an item) is fine. Faking something the game can't do is not; restructure the shot instead (see the Gold→Rainbow montage in the example).
• No computer-use. Everything goes through MCP eval calls, Python and ffmpeg.
• Keep cards and text sparse ("theme without noise": no extra noise on tools). The game's own UI is the best text.

Workflow

1. Plan

Read references/shot-list-template.md. From the game's GAME.md, FINISHED.md and source, write the shot table (hook in the first 2-3 s, core loop, rare moment, social, base/progression, an extra system, title card, a CTA for social only) and show it to the user before recording. Then write <game>/trailer/shots.json (schema in references/luau-api.md; start from assets/shots.template.json, or references/example.shots.json for a full example). python3 $SK/scripts/build_kit.py list --shots <shots.json> sums the raw footage.

2. Gameplay-POV and cinematic shots (Luau)

• scripts/TrailerDriver.luau runs one shot on a playtest client: teleports to the start pose, disables the keyboard controls, walks waypoints (Humanoid:MoveTo, pathfinding, jumps, human jitter), turns to face targets, presses ProximityPrompts (InputHoldBegin/End), invokes remotes or bindables, and swaps cameras on cue or on game events. Its player cam is a lagging follow with mouse-like drift, tremor and glances. The game HUD stays on for gameplay shots and goes off for cinematics; the Roblox top bar, CoreGui and cursor are always off. Every run first stops the previous one and restores everything afterwards.
• scripts/CameraRig.luau has the cinematic presets: dolly/spline/flyover, bezier, orbit, crane, push-in, whip (with motion blur) and static. All are eased through TweenService curves and have configurable durations.
• Get them in: build_kit.py rbxmx → import_rbxm into ReplicatedStorage (edit mode) → start the playtest → send build_kit.py call --shot ID with eval_client_runtime. Run build_kit.py server --shot ID with eval_server_runtime first if the shot has setup. Details and the full action list: references/luau-api.md.

3. Record

references/recording.md. In short: record.py calibrate once (the driver paints the viewport cyan and the script finds it), then for each shot record.py shot ID --start-ms <startsAtMs> --dur <dur>. It waits for the driver's scheduled start, records preroll + shot + tail of just the viewport, and stores the exact trim offset. If screen recording is unavailable, record.py stitch turns saved capture_screenshot frames into a clip.

4. Edit

references/editing.md. edit.py build --cut roblox --format landscape makes the Roblox upload (30 s max, 1080p60 H.264, no CTA). --cut social --format both makes 16:9 plus 9:16. Text is drawn with Pillow because Homebrew's ffmpeg may have no drawtext. If Fredoka One isn't installed, ask before downloading it into assets/fonts/; it falls back to Arial Rounded Bold.

5. QA

qa.py clips --shots ... after recording; qa.py final <mp4> --roblox after editing. It checks for dropped frames, black and frozen frames, Studio-UI bands at the edges, the cursor flag and the Roblox limits, and writes a contact sheet. Open the sheet with Read and look at it: a stray Studio panel, a cursor or the wrong HUD state show up there. Then show the user the cut (path plus sheet) and take notes for a recut. Recuts only need edit.py.

6. Clean up

Stop the playtest, delete ReplicatedStorage.TrailerKit, run record.py clean --out <trailer> --shots <shots.json>, and remove <trailer>/build/. Keep clips/ (the source footage) and out/.

Reference map

Scripts

Validate after changing scripts: python3 -m py_compile $SK/scripts/*.py and $SK/scripts/check_luau.sh $SK/scripts/*.luau.

Known gaps (fix them here when you hit them)

• The driver can't click GUI buttons. Use the remote the button calls (invoke), as the hatch shot does.
• A fixed localOffset from a tag is a first guess; expect to adjust it after the first take of each shot.
• The player cam doesn't model mouse-wheel zoom. Use look.dist to change distance between beats.
• Server setup can't require the live game modules: execute_luau/eval_server_runtime get a FRESH require cache (measured 2026-10-11 on a pet-hatching game: PlayerState.all() was empty while the player was loaded). Put setup in a RunContext=Server Script imported next to the kit that exposes a BindableFunction, and make server snippets :Invoke it. Pattern: a TrailerHook Script (trailer only, never saved in the place) that requires the game's own modules from inside the game's server VM and creates ServerStorage.TrailerHook (BindableFunction, :Invoke(cmd, args) -> (ok, result)), with one small command per setup step (give cash, add an item of a given tier, make a timer ready, force the next roll's odds, restore). It saves every config value it changes and restores them on restore and when the Script is destroyed. Package it into an .rbxmx the same way build_kit.py packages the kit.
• Studio's viewport with Explorer/Properties docked is about 1.26:1 on a 1470x956 pt screen; hide the panels (or View > Full Screen) before calibrating, or the 16:9 crop throws away a third of the picture.