Field Builder XR

Cinevva's analyzer read this game's design doc and its source, then wrote the brief below. "Make your own" hands it to the game creator as your opening message, so you start from a real spec rather than a one-line idea.

Create a playable Three.js mixed-reality baseball field builder titled “Field Builder XR.” The game should have a desktop/mobile 3D preview plus WebXR AR support. Use a third-person/free-camera perspective in desktop preview: a perspective camera starts around (0, 2.2, 9.5), looking down slightly over a large green baseball field with a tan dirt infield arc, blue sky-colored background, soft fog, shadows, and bright natural lighting. In AR mode use a transparent renderer so the real camera passthrough is visible; hide the virtual sky, grass plane, and infield, and anchor the miniature baseball field to a scanned real-world floor.

The core activity is building and testing a baseball field. On startup, place a default field: a white home plate near the foreground, a raised brown pitcher’s mound with a small white pitching rubber far away, three oversized white diamond-rotated bases, white chalk batter’s-box outlines near home plate, and a curved outfield fence made from repeated suburban fence sections along the far perimeter. Include a Reset Field button that restores this layout and clears active pitches and physics baseballs. The green field should be a broad flat plane and the infield should be a tan circular/arc dirt area. Fence sections should appear as blue/teal suburban-style fence panels when the external GLB asset is available, with a simple teal rectangular fence fallback otherwise.

Let the player place additional field pieces wherever the floor reticle points. Available selectable pieces are Home Plate, Pitcher Mound, Base, Batter Box, and Fence. The selected piece should be shown as a translucent pale-green preview attached to a green ring-and-dot placement reticle. Home plate is a beveled white pentagonal plate; the mound is a low brown truncated cylinder with a raised white rubber; a base is a large white square rotated 45 degrees; a batter box consists of two mirrored rectangular chalk outlines; a fence is a scaled suburban fence section. Add a prominent “Place selected” button. Desktop controls: WASD moves the camera, arrow keys or Q/E turn (up/down arrows adjust pitch), dragging on the canvas turns the view, and Space places the selected piece. Snap desktop floor targeting to half-unit increments. On mobile, show a translucent circular virtual joystick at lower right for movement, retain drag turning, and use touch buttons for selection and placement.

Add a pitching/testing system. The “Special Pitches” panel has Fastball, Curve Ball, Slider, and Spawn Baseball controls. In desktop preview, clicking a pitch button immediately launches a visible white baseball from the pitcher’s mound toward home plate over about 1.55 seconds, with a slight upward arc. Fastball travels mostly straight, Curve Ball visibly bends sideways using a sine-shaped lateral offset, and Slider moves sideways progressively. Remove the pitch ball when it reaches home plate. Display status text describing the selected or thrown pitch. Spawn Baseball in desktop mode creates a detailed larger white baseball with two red stitch arcs by the camera’s right side; it falls under gravity, bounces with damped velocity, rolls, and eventually sleeps/removes after repeated bounces or about ten seconds. Give spawned baseballs real spherical geometry, white material, red curved stitch details, shadows, gravity, collision with the ground, and pitch-specific lateral motion when thrown.

Support mixed reality interaction. Include a “START MIXED REALITY” WebXR AR button requesting hit-test and optional local-floor/bounded-floor/dom-overlay features. Include Scan Floor and Controller Floor controls. In AR, initially hide the virtual ground and infield and show a real camera background. Scan Floor uses hit-test results: show a green reticle on detected surfaces, fill a green progress meter while the user slowly keeps pointing at a stable floor location, and after the meter fills anchor the field there. Controller Floor instead asks the user to place a tracked controller flat on the physical floor and hold it still for 3 seconds, filling the same meter before anchoring. When anchored in AR, scale the entire field down to about 0.18 and orient it toward the camera; show a translucent green detected-floor disk/grid guide. Place all added pieces relative to this floor anchor. The reticle should disappear from the normal desktop overlay in live AR.

In AR, show simple visible hand/controller models: skin-colored palm and fingers, colored controller shell, dark handle, and a thin pale-green aiming beam. Attach a right-hand world-space spawn menu to the right controller. It is a dark translucent vertical panel with labeled buttons for BASEBALL, BASE, HOME, MOUND, BOX, FENCE, FAST, CURVE, SLIDER, SCAN, and FLOOR. Aim the other controller at the menu and use select/trigger to activate buttons. BASEBALL spawns a small stitched baseball on the right hand. Selecting a field piece changes the placement tool. FAST/CURVE/SLIDER selects a pitch and throws a held baseball with that movement. SCAN starts floor scanning and FLOOR starts controller-floor calibration. Pressing the controller trigger while holding a ball throws it in the controller’s forward direction using controller movement velocity, gravity, bounce, and the selected pitch behavior; trigger without a held ball places the selected field piece at the reticle. Use a throw sound effect if available.

Build a translucent, readable HUD over the scene with a small title “Field Builder XR,” a status/instruction line, a top-right Reset Field button, and on desktop/mobile a START MIXED REALITY button near the top-left. Put a dark green blurred rounded “PLACE” panel along the bottom-left with green section headings and buttons for Home Plate, Pitcher Mound, Base, Batter Box, Fence, plus a wide cream “Place selected” button, scan progress meter, and a hint such as “MR: use Scan Floor, or tap Controller Floor and hold your controller on the floor for 3 seconds.” Put a separate dark rounded “SPECIAL PITCHES” panel on the right with Fastball, Curve Ball, Slider, and white Spawn Baseball buttons. On narrow screens move the pitch panel to the upper-right and display the joystick. Use rounded buttons, white text, pale green highlights, cream primary controls, translucent dark panels, and a clean system sans-serif interface matching the supplied screenshot. Keep the HUD usable as a DOM overlay during AR. Track and display status feedback for selected tools, placement, scanning progress, floor anchoring, spawned/held balls, and thrown pitches. Provide a functional reset, responsive resize handling, shadows, fog in desktop mode, and stable frame-loop updates for camera movement, reticle placement, XR controllers, pitches, and physics baseballs.