# Musical Theater Basel — ground-floor fair model

Primary references: o_floor_1st_option.pdf, 0_floor_stage_1st_option.pdf and the supplied screenshots in work. The complete ground-floor architectural drawing (page 3 of Beilage 4+5) establishes the alignment between foyer and stage. Photographic reference: https://tourmkr.com/F1KeZuexzQ/8393286p&316.81h&66.12t

## Geometry and dimensions
- Model units: metres. Y is vertical.
- Fair-wall default height: 3.00 m, requested by the user on 14 October 2026.
- Fair-wall thickness: 0.10 m for visualisation; not specified in the source.
- H1–A1 grid length: 39.30 m = 5.50 + 5 × 5.66 + 5.50.
- Façade-to-F3 grid: 6.96 m = 1.02 + 5.94; adjacent grid intervals 2.83 m.
- Left upper partition: 7 m end return, 4 + 5 m back wall, 4 m dividers/returns.
- Left lower partition: three 4 m back-wall bays, 4 m dividers, 7 m end return.
- Front screening wall: 6 + 5 + 5 + 5 + 6 = 27 m, with four 4 m dividers and two 2 m end returns.
- Main entrance, columns, room footprints, two spiral stairs and side entrances are traced against the source grid. The front screen is placed ahead of the Kasse and both straight stairs. Side entrances lie behind the two façade-side partition runs, with access around their ends.

## Accuracy limits
This is a dimension-led reconstruction from a scanned, hand-annotated drawing, not a surveyed CAD model. Written partition lengths take precedence over the pen stroke lengths. The upper front bay is marked 6 m but scales to approximately 5.4 m in the scan; imposing 6 m moves subsequent dividers relative to their pen strokes. The source plan tab is included for direct comparison. An exact match to both those conflicting sources is not possible without a corrected dimension.

Areas are copied from the source and sum to 204 m². The irregular 25 m² and 22 m² bays and the upper front 20 m² bay are not independently validated by the supplied dimensions. The 25 m² areas do not equal a simple 7 × 4 rectangle.

The existing building is shown as a roofless cutaway. Existing heights, stair rise, railing details, glazing height, opening hardware and wall thicknesses are illustrative. The two spiral stair locations and footprints follow the plan; the helical treads are an indicative representation. Auditorium seats are schematic context, with no claim to the actual seat count or row geometry. Display artwork, tables and magazines are illustrative exhibition dressing.

## Files
Open ground-floor-3d.html in a modern browser. It embeds Three.js and the source image and works offline. The OBJ/MTL geometry and JSON model are adjacent. Keep the MTL beside the OBJ when importing into 3D software. The height slider affects the viewer only; downloaded model geometry retains the default 3.0 m wall height.

## Material and lighting update
The viewer now includes stone tile and terracotta textures, metal handrails, glazing frames, bar-top finishes, warm/daylight lighting and an eye-level camera. All original model vertices and fair-wall dimensions remain unchanged, verified against file hashes. Added surface details are illustrative. The downloadable OBJ remains the unchanged base geometry; the enhanced rendering is in the Three.js viewer.

## User correction: columns and wayfinding
Removed the four intermediate foyer columns immediately ahead of the front exhibition screen (x=12.62 m; z=11.16, 16.82, 22.48 and 28.14 m), including their decorative collars. Added two MORE WORKS floor arrows pointing along the end corridors beside the spiral stairs. Fair-wall geometry, dimensions and 3.00 m height remain unchanged. Floor signs are included in the viewer and model metadata; the OBJ includes the column correction.

## Tour materials and entrance branding
The viewer uses sampled plaster textures from the supplied tour screenshots (15.34.18), and the supplied photo basel logo.png. The earlier procedural stone floor has been restored at the user's request. The entrance sign is 6.0 m wide and 1.30 m high, centred 3.20 m above the floor over the front entrance. This sign size and mounting are a design proposal, not a surveyed feature. The supplied 2027_poster-01.jpg is displayed on the front glazing. Bar perforations and metal finishes are visually matched to the photographs. Existing corrected geometry and all foyer fair-wall dimensions are unchanged.

## Revised stage layout — 7 October 2026

The current stage reference is IMG_0839.HEIC, supplied at 13:23 on 7 October, with the tour screenshot at 13:27 providing the raised apron appearance. It supersedes the booth layout in 0_floor_stage_1st_option.pdf. The updated drawing is embedded under Stage plan and linked as stage-plan-revised.jpg.

The stage now has 19 booths, numbered 11–29 for continuity with the ten foyer booths. Model identifiers are not source booth numbers. Stage booth areas total 274 m²; the complete exhibition total is 29 booths / 478 m².

| Model booths | Layout | Dimensions | Area, each |
| --- | --- | --- | --- |
| 11–14 | Left / north side, four booths | 3.5 × 4 m | 14 m² |
| 15–18 | Right / south side, four booths | 3.5 × 4 m | 14 m² |
| 19 | Top / rear end | 4 m back, 4 m outer return, 2 m inner return | 12 m² |
| 20 | Top / rear middle | 6 × 2 m | 12 m² |
| 21 | Top / rear end | 4 m back, 2 m inner return, 4 m outer return | 12 m² |
| 22–29 | Central island, four pairs | 4.5 × 3.5 m | 15.75 m² |

The two rear end booths use trapezoidal footprints inferred from the unequal 4 m and 2 m returns. Each polygon has a calculated area of 12 m², matching the source label. This interpretation is flagged for user confirmation. The central island's shared spine is 18 m long; cross dividers are 7 m long. Each side row has a 14 m back wall and 4 m returns. The rear spine is 14 m long (4 + 6 + 4).

Fair walls remain 3.00 m tall, as confirmed by the user. Areas and written lengths describe partition centre lines; the illustrative 0.10 m wall thickness reduces clear interior space. The source's 574.08 m² annotation refers to the stage room, not the combined booth area. Original foyer vertices, labels and partition lengths are unchanged.

The stage remains aligned to the architectural B4 grid at x=55.63 m. Pencil positions and undimensioned details are approximate. A curved front apron, dark fascia and red timber lip follow the supplied photograph. Its 0.90 m deck height and 2.85 m centre projection are visual assumptions; the image establishes that the stage is raised but supplies no numerical elevation or radius. The first central pair sits on the apron, following the plan's extension beyond the stage-front line.

Stage-wing and rear passages use the revised 2 m width. The long foyer-to-stage route previews retain the previous 3 m width; their transition into the stage wings narrows to 2 m. Corridor bends and ramp levels remain illustrative, rather than verified access details.

The supplied 2027 poster now has two separate, oppositely facing prints on the glazing. Its lettering reads normally from both outside and inside. Stage artwork and magazine tables retain the foyer style. Auditorium seating, curtain gathering and furniture are illustrative.

The OBJ/MTL and JSON include the revised partitions, deck, apron, fascia and circulation geometry. Furniture, framed artwork, floor outlines, schematic seats and posters are rendered in the HTML viewer. All 19 stage footprint areas and all 46 fair-wall segments were checked; fair-wall heights remain 3.00 m. Stage deck and apron top surfaces point upward so their raised level displays correctly.

The viewer offers Whole ground floor, Foyer, Stage booths, Stage edge, Walk foyer, Walk stage and both source plans. ground-floor-with-stage.html is the current viewer address; the same updates are also included in ground-floor-3d.html.


## First-floor gallery - 14 October 2026

The new reference is 1_floor_1stoption.pdf. The dedicated first-floor-3d.html link opens directly at #firstfloor. First-floor booths, Walk first floor, Top view and First-floor plan are available, together with explicit Ground floor / First floor / Both floors controls. Existing ground-floor and stage geometry is retained.

The first-floor gallery is placed at +5.36 m, the level shown in architectural section 9.A of Beilage 4+5. The facade sheet rounds/labels the first floor +5.38 m; the model follows the gallery section. Both stair centres retain the accepted ground-floor alignment (x=9.76 m, z=9.12 and 31.00 m). Treads and metal handrails are indicative. The central Luftraum and both stair wells are true openings in the slab, with a curved east boundary and open guardrails. The architectural outline beyond the cropped plan is simplified.

Nine model booths, numbered 30-38, retain the handwritten areas and total 174 m²:

| Booth | Plan position | Plan area | Written wall dimensions |
| --- | --- | --- | --- |
| 30 | North-west end | 16 m² | 4 m back, 4 m shared divider, 6 m end wall |
| 31-35 | West gallery, five bays | 22 m² each | 5.5 m back, 4 m dividers |
| 36 | South-west end | 18 m² | 4.5 m back, 4 m shared divider, 5.5 m end wall |
| 37 | North-east end | 15 m² | 8 m back, 2.5 m return |
| 38 | South-east end | 15 m² | 7.5 m back, 4 m return, 2.5 m short return |

The two AC/air recess screens are each 5.5 m. Each landing screen beside the central void is 4.5 m. There are 24 first-floor fair-wall runs, all exactly 3.00 m above the gallery floor. All written run lengths are reproduced in metres. The five 22 m² rectangular bays calculate as 5.5 × 4 m. End-booth areas are copied from the plan, with wall extensions retained; the sketch does not establish an unambiguous closed polygon for those booths. The displayed end-booth labels explicitly say plan area. Their furniture locations are indicative.

As on the earlier floors, framed display works and magazine tables are illustrative. Existing heights, finishes, guardrail details, recess depths and undimensioned room outlines are visual approximations. First-floor OBJ/MTL and JSON are provided separately, at +5.36 m. The original ground-floor OBJ/MTL exports remain unchanged.

Both levels together show 38 booths and 652 m² of plan-labelled exhibition area. The HTML pages embed Three.js and all source imagery and work offline.


## Default fair-wall height - 14 October 2026

The user changed the default fair-wall height to 3.00 m across the foyer, stage and first floor. The initial slider value, model geometry, JSON metadata, OBJ exports and selection text use this height. The slider remains adjustable and anchors each partition to its floor level. All X/Z positions, written wall lengths, booth areas, floor levels and existing building elements are unchanged.