Learn the Roman Rite of the Mass by taking part in it. Choose a role, such as Priest, altar server, Master of Ceremonies or Sacristan. Then walk through a whole Mass in a 3D church, answering what you should do or say next.
▶ Play the Holy Mass simulator
It runs in any modern browser on a computer or tablet. There is nothing to install and no account. Other pages:
The Corpus Christi scene is illustrative. The route follows local direction; canopy, lights, incense on the route and prayer stations are not presented as universal requirements.
From setup, choose Practice room for three optional, untimed mini-games: Know your church (find five targets using numbered markers in the 3D scene, with named or description clues and picture hints), Sacristy scramble (set out a selected cupboard checklist while leaving distractors behind), and Line up the procession (move minister groups and assign their carried objects). Use touch or keyboard controls; no dragging or fast reactions are required.
Preparation and procession currently support four labelled ordinary Mass arrangements: one server, four servers, five servers with incense and a Deacon, or two servers with a processing lector. They do not cover special rites or celebrations with a Bishop. Cross and candles share a rank; spacing and some preparation alternatives are schematic. These are illustrative exercises, not a complete preparation course or an approved ceremonial.
Every finished round counts as completed. Separate 1-3 stars show accuracy (2 at 70%, 3 at 90%); church-finding retries, reveals and hints reduce accuracy. Practice records use their own local save, not celebration milestones, scores or settings. Replay freely, or return to setup with Escape; an existing celebration can still be resumed or restarted.
Found a mistake or have an idea? Use the 💬 Feedback button in the game. It is anonymous.
For richer surfaces, use Detail: Standard or High. Under The church, choose Sanctuary floor: Pale marble for veined stone slabs, or sandstone, terracotta or slate. Wooden furnishings show grain and metal vessels have a soft sheen. All textures are generated locally, so they work offline. Low keeps flat finishes for slower devices; Auto chooses Low or Standard.
This is an illustrative teaching aid, not a substitute for the approved Missal, ceremonial training or local custom. Prayer texts are short paraphrases.
Everything runs from local files (file://) with no build step or server. To
work on it offline, clone the repository and open mass-game.html.
docs/SPEC.md: what the project does and must keep doing.docs/DEVELOPMENT.md: the resume checklist, project
status and workflow for new contributors and AI sessions.docs/MINI-GAMES.md: persistent mini-game ideas and
implementation statuses.docs/GAME-DECISIONS.md and
docs/DECISIONS.md: the decision logs.docs/SOURCES.md: sources and licences.docs/DIRECTOR.md: the director’s notes.
docs/director-script.json preserves the complete baseline animation script.Open mass-3d.html in a modern browser for the interactive 3D version.
Everything is local; no server, installation, account or internet connection is
needed. Keep the JavaScript, stylesheet and vendor folder beside the HTML.
WebGL must be enabled in the browser.
Drag the scene to orbit, right-drag to pan and scroll to zoom. The camera menu provides church, altar, ambo, chair, congregation and overhead views, plus minister-follow views. Clicking a minister also follows them. Reset view restores the chosen camera. On touchscreens, use one finger to orbit and two to pan/zoom. Follow the action automatically tracks active gestures, speakers and moving ministers, frames the altar during elevations, and uses wider shots for the processions and Communion. Transitions are smoothed; choose a fixed view when you want full manual camera control.
Use Play, Previous, Next, the timeline or the Order of Mass list to navigate. Space toggles playback and the arrow keys change steps when no form control has focus. Scenario changes pause playback and restart the current step.
The setup controls change both the figures and their duties:
mass-animation.html retains the original animated floor-plan view. Both
versions share the rite and movement data in mass-rite.js; the 3D version
applies its scenario adaptations in mass-scenarios.js.
This is an illustrative Sunday Mass in Ordinary Time, not a substitute for an approved Missal or ceremonial training. Rubrics are paraphrased, timings and gestures are schematic, and speech uses excerpts rather than a complete Missal. The original paragraph references require verification against the approved Missal and local norms. Postures, options and Communion practice vary with the applicable norms.
The offline renderer uses Three.js 0.128.0 and its OrbitControls, distributed
under the MIT license in vendor/THREE-LICENSE.txt.
To check the scenario duties, timelines and sampled motion states, run
node mass-scenarios.test.cjs from this folder.
Enable Train with one server, then choose a member of the configured team. The camera follows that server and shows current and next duties. Jump to next duty pauses playback and takes you to the next movement, gesture or object handoff. Cues use the scenario’s combined duties, including the omission of the bell when the same person is incensing the elevation. A zero-server setup disables training. Training cues are illustrative, not a complete checklist.
The original controls below are the Legacy layout. For portable, named profiles, use Parish preparation in the explorer or the game’s Engine settings, or Prepare a parish on the game setup sheet.
Choose the altar, ambo, celebrant/deacon chairs, credence table, servers’ bench or tabernacle. Edit X (left-right, 100-900) and Depth (back-front, 35-260), then apply. Related nearby destinations, vessels, labels and cameras follow the furniture. Positions are restricted to the sanctuary; at least 100 layout units of centre clearance from the altar are required for other furniture. Movement paths are schematically deformed, not collision-aware route planning. The church shell, pews and nave remain fixed. Rotation and floor-height editing are not included.
Choose a preset and apply it for a central/left ambo, mirrored/right ambo, compact chapel, broad sanctuary with side chair, or central tabernacle with side chair arrangement. These are illustrative furniture configurations in the same church shell, not measured architectural plans.
Layouts are saved in this browser’s local storage, subject to browser permission and file-URL storage behavior. Export/import a JSON file for a portable copy. Default layout restores the original arrangement without changing the original floor-plan animation.
The first maintainer editor supports a prepared rectangular church shell, one sanctuary level and a right-hand sacristy. It is a starting template, not a measured recreation of any real church. Irregular plans, changing the shell dimensions, new openings, furniture rotation, different floor levels and extended outdoor routes need additional prepared geometry and navigation work.
st-example. Keep the ID when revising
the same church and increase its revision when publishing an update.The church selector keeps the published generic template, the Legacy layout, and up to 50 locally applied church profiles. Switching churches does not delete other local profiles. Layout selection is separate from celebration presets. While a profile is active its furniture and seating override the legacy layout and tabernacle/seating appearance controls; other appearance choices still apply. Legacy settings are retained when switching back. Church changes are blocked during an unfinished game.
Browser storage is only a convenience, particularly under file://; export
files for portable copies. The separate storage keys are
mass-parish-profile-v1, mass-parish-library-v1 and mass-parish-draft-v1.
Existing layout, setup, score and Path keys are unchanged. There is no upload,
account or automatic publication. A maintainer reviews exported JSON and
incorporates approved data into the bundled classic-script profiles.
Later user contributions: profiles already have stable church/object IDs, schema versions and revisions. A future patch format can record changed fields against a specific base revision with expected old values, so conflicts are reviewed instead of silently overwriting newer work. Patch export, patch import and online submission are not implemented. For now, send a full profile manually; new photos or models are separate attachments.
Start with one pilot church: an annotated floor sketch, entrance-to-sanctuary and reverse views, corner views, sanctuary/sacristy coverage and exterior views. Mark doors, pew blocks, aisles, steps, furniture and actual minister routes. Measure overall and sanctuary dimensions, aisle and door widths, step heights and altar size; mark guesses as estimates. Add close views of the few features that make the church recognisable.
Original-resolution photos are sufficient initially. Most are modelling references, not textures. Perspective/colour correction, privacy removal, texture preparation and any model simplification happen outside the editor. Confirm rights to distributed photographs and directly reproduced artwork, and avoid identifiable people and private notices. No photos or measured plans are bundled with the generic template.
If you already have estimate cards, satellite images, Street View captures
and interior photos, an agent can sort them by following
docs/PARISH-INTAKE.md. It builds one folder per parish
under parishes/ with a source manifest and a parish spec, with values such
as dimensions, roof pitch, materials, belfry and fixture positions. It
excludes or flags doubtful images, for example Street View taken from the
wrong side of the street, and drafts a training layout. You then check every
doubtful item in parish-review.html, which opens directly from the
folder. Press A to accept, R to reject and S to skip, or press Ctrl+Enter to
accept with a comment. Then export the decisions and give the file back to the
agent (node parish-intake.cjs apply <file>).
Enable Speak during playback and choose voices independently for the Priest, Deacon, Lector, Psalmist and People. Only voices reported as local by your browser are offered; no external text-to-speech service is used. Installed voice availability differs between browsers and systems. The People voice is a single synthesized speaker, not a choir. Test the Priest’s voice before playback.
The timeline waits for each spoken cue to finish. Pause, seek, scenario changes and language changes cancel the current utterance; resuming may restart the current excerpt. Speech speed is separate from animation speed. Stage directions and chant labels are skipped; printed sung words are spoken rather than chanted. English speaks the existing abbreviated script. Latin is a partial pack of traditional responses, not a translation of the full script or a change of rite. Missing translations are explicitly indicated in captions and not spoken in English as a fallback. Most systems do not have a Latin voice: you can explicitly select another installed voice, but its Latin pronunciation may be unsuitable.
Export a language template, replace its name, id, language tag and translations, then import it. Supply wording you are entitled to use and verify it against the approved liturgical text. The UI and training/rubric explanations stay in English. An imported pack uses this structure:
{
"version": 1,
"id": "la-parish",
"name": "Parish Latin",
"lang": "la",
"texts": {
"The Lord be with you.": "Dominus vobiscum.",
"And with your spirit.": "Et cum spiritu tuo."
}
}
Keys match the original English caption exactly. Empty translations are omitted. Packs are saved locally when storage is available. Export templates from relevant scenarios if you need wording from different staffing arrangements.
Run node mass-features.test.cjs to check layout transforms, training cues,
language validation and speech scheduling with a simulated speech engine.
Choose Pre-generated AI recordings as the audio source. These MP3 files play offline without installed system voices or API credentials. Individual characters have fixed synthetic voices. Congregation responses mix several distinct voices (four by default for new generation; the first published clips used six), small timing/speed differences, stereo placement and restrained echoes; they are not a recording of a real congregation and do not simulate singing. Use Test congregation to preview a response.
The static pack covers the abbreviated English script and a partial Latin pack. Latin uses Latin phonemes with English-trained voices and is explicitly experimental. Review pronunciation before using it for training. The UI reports current audio coverage; missing clips are skipped with a status message, rather than silently switching to live synthesis.
Generation can be resumed: completed clips are skipped. Large model files and
the generation environment are excluded from Git. Playback needs only the
audio assets and manifest.
Clips have readable names, grouped by language and sorted in Mass order:
audio/en/05-people-and-with-your-spirit-40b93bf5.mp3 is step 5 (first use),
spoken by the people. The final 8 characters are a fingerprint of the exact
wording, so a changed text gets a new file. audio/index.csv lists every
planned clip with its steps, step title, English source text, spoken text and
whether it has been recorded; it opens in a spreadsheet and is a convenient
starting point for translation work.
To generate or complete the pack:
audio-requirements.txt in an
isolated virtual environment.kokoro-v1.0.int8.onnx and voices-v1.0.bin from the official
model-files-v1.1 release.node prepare-audio.cjs audio/audio-jobs.json.python generate-audio.py --model <model-path> --voices <voices-path> --jobs audio/audio-jobs.json --experimental-latin.
Omit the Latin flag for English-only generation. Add --group-size N (2-6)
to change the number of congregation voices; delete existing ppl clips if
they should be regenerated at the new size.node snapshot-audio.cjs to write the manifest and audio/index.csv
from the clips that exist, including while generation is still running.
It also renames clips from the earlier hash-only naming scheme.Use an environment outside this repository for model downloads and Python
dependencies. See docs/SOURCES.md for upstream licenses and attribution.
Open mass-game.html (also straight from the folder) to play through a Mass
in a role. The decisions made while building it are logged for review in
docs/GAME-DECISIONS.md.
Both the game and the 3D explorer have appearance options: servers’ robe and cincture colours (white by default), no cincture if preferred, and an optional pectoral cross on the senior/general server. This cross is a local custom option, not a universal prescription. Priest and Deacon vestments default to the coming Sunday’s season (today when it is Sunday), with a manual colour override. The simplified calendar includes Gaudete/Laetare rose, which is optional, and some major Sunday feasts; override it for local calendars. The main crucifix has a corpus by default. Sanctuary windows can be stained glass (default), fine leaded grids or plain glass; the floor defaults to warm sandstone, with terracotta, slate and pale marble alternatives. The gold tabernacle defaults to a separate plinth behind the altar; choose left, right or a custom position. Applying a layout preserves it as custom.
You begin in the sacristy (ministers, M.C., sacristan) or outside the doors (congregation): vest, take what you carry, line up, or take holy water and find a pew. Nonprocessing readers, the usher and EMHC prepare at ordinary pew places. During Mass the clock stops at each of your duties. Number keys pick options; click markers or the floor to move. Every answer shows the rubric reference. After Mass you return to the sacristy (or leave), and a summary lists every decision with its reference and your score; best scores are kept in the browser.
After two wrong answers, either click the green correct answer or press Continue. During Mass, Redo previous returns to the last completed decision and rolls back its score and log (and any in-progress answer). Repeated clicks go back further. The key-moments setting includes both the gesture and the spoken words alongside movements, so walking to the chair does not replace the Sign of the Cross before the Greeting.
The Questions button in the header turns questions off at any time (and back on): the current and later duties are done for you and are not scored. With Symbols on (game options), each answer, checklist item and log line carries a small icon for the object it is about, and hovering over (or tabbing to) an answer shows a pulsing ring in the church on the thing, place or minister it refers to. Congregation members and servers vary in height, and some of the congregation are children.
Use the timeline to move forward to your next unanswered question, once the current question is finished; it does not award points or bypass questions. Choose animation speed with the selector or adjacent slider. The Priest may preach at either the chair or ambo. Reminder questions also name the duty due. Readers and Psalmist sit with the people; everyone stands through the final blessing and exit procession. The longer sign-of-peace interval shows exchanges between neighbours.
The usher collects offerings and, when a gifts procession is selected, joins it with the collection basket. The bread and wine go to the altar; the collection is placed at a suitable place away from it (GIRM 73, 140). After the Priest incenses the gifts, cross and altar, the Deacon (or server) incenses the Priest, then the people. Optional EMHC assistance assumes proper deputation and genuine need, starts after the Priest’s Communion, and does not include purification. Reserved hosts are fetched from the tabernacle and reposed by default (an option); GIRM 85 prefers hosts consecrated at the same Mass.
Existing generated audio for spoken parts plays by default. The sound button mutes speech and effects; the setup checkbox can disable recordings separately. The second reader shares the Lector’s recorded voice, and the EMHC shares the recorded Communion formula. Missing clips are reported in the speech controls. Effects (altar bell, sacristy bell, thurible chains, right/wrong cues) are synthesised in the browser (bells are modelled from real bell partials with a little church reverb). For visual clarity and accessibility (including when sound is muted), active altar bells, sacristy bells and thurible swings trigger a transient HUD chime badge with expanding ripples, paired with horizontal golden wave rings across the 3D sanctuary floor. Everything plays offline. Bell customs vary by place, so each bell is optional.
On a phone, the top menu folds into a ☰ button, and the camera controls fold into 🎥 and ✥ buttons in the corners of the 3D view. Tap anywhere else to fold them away again.
New game can be cancelled (button or Esc) to return to the game. The 🔊 button mutes all sound. Detail (Auto, Low, Standard, High) suits low-spec devices: Standard has local surface textures, High has sharper textures and shadows, and Low disables textures and shadows. Switching detail updates finishes immediately; antialiasing still needs a reload. The start bell (on by default) rings once the procession has gathered at the entrance. Reserved hosts are used and reposed by default. The cupboard also holds a monstrance for a future Exposition scenario.
feedback-config.js (FEEDBACK_ENDPOINT). Until then the note is copied
to the clipboard and offered as a text file to send by hand.
node mass-scenarios.test.cjs
node mass-features.test.cjs
node mass-assets.test.cjs
node mass-game.test.cjs
GitHub Actions runs these checks on pushes and pull requests. After editing
baseline direction data, run node export-director.cjs and commit the updated
director export. No full liturgical text, account credentials or AI model weights
are included in this repository.