RTE — Rollingcats Transit Expansion

Track geometry and construction tooling for Minecraft Transit Railway 4.0.

Track geometry

• Four path modes: native, auto Bézier, multi-point curve fitting, manual Bézier
• Vertical curves with configurable radius, gradient shown in ‰
• Cant (superelevation) — roll distributed along the track; vehicles, camera and the player's standing plane all follow
• Arc-length sampling through a unified TrackPath interface
• Geometry analysis: curvature, minimum radius, gradient rating

Construction tools

Parallel line copy, along-line array, catenary planning, manual track chains with draggable endpoint handles, and undo (sneak + right-click air).

Legacy resource pack compatibility

MTR 3.x packs lose a lot of functionality under 4.0. RTE adds a compatibility layer for the migration gap — every item below is an individual toggle:

• Two JS runtimes (Rhino / GraalJS), selected per pack via the engine field
• Per-function script backoff, so one bad script can't throw every frame
• Time base conversion between 3.x (ticks/seconds) and 4.0 (milliseconds)
• default.png matched by filename instead of exact path
• Relaxed pack_format validation for packs built for older MC versions
• DOORWAY parts derived from door positions (3.x has no such concept)
• Built-in gangway suppressed when the pack ships its own
• Oversized textures downscaled on read

Measured across 322 community packs: loading errors dropped from 567 to 19.

Server-side data sync

MTR only syncs data near the player. With RTE installed on the server, three on-demand requests are added (falls back to vanilla behaviour when absent):

• Full vehicle path — fixes ETA and average speed derived by resource packs
• Full rail set (paged) — the dashboard no longer loses segments at distance
• In-viewport vehicle positions (10 Hz, extrapolated)

Resource workbench

In-game vehicle resource editor: list loaded vehicles, snapshot them, edit fields through a recursive JSON editor, preview models, import textures, export as JSON or a self-contained resource pack zip.

Included

Decoration objects with a property editor (7 built-in models), direct nodes and a visitor-counting turnstile. Interface built on ImGui, no Cloth Config needed. 10 languages.

Requires: MTR 4.0+, Architectury API. Fabric builds also need Fabric API. Optional: MSD (enables the catenary planner).

License: All Rights Reserved. Free to download and use on personal or server setups; recording, streaming and screenshots are welcome with attribution. Redistribution, modification and derivative work require written permission.

This mod requires Minecraft Transit Railway 4.0 or newer and Architectury API. Fabric users also need Fabric API.