Climbable Ropes for Create Aeronautics

NeoForge addon for Create: Aeronautics, specifically the bundled Simulated physics module that handles ropes. Adds two empty-hand climb modes alongside Simulated's existing wrench-driven zipline system: near-vertical rope strands, and plunger-fired ropes between paired LaunchedPlungerEntity projectiles.

How it works

Simulated already has a rope-strand riding system (ZiplineClientManager) that lets the player slide along a rope held by Create's wrench-tagged item. That system is left completely untouched (no mixins, no overrides), so ziplines behave exactly as in vanilla Simulated.

This mod adds two separate climb modes driven by empty-hand interaction.

Vertical rope strands

• The player right-clicks a near-vertical rope strand with an empty main hand.
• A ClientTickEvent.Post handler (ClimbController) raycasts against rope strands using Simulated's own ZiplineClientManager.raycastRope helper.
• If a strand within reach is hit and the segment's closest-point normal is at least 85% vertical (~32° from perfect vertical), we record the rope UUID, send Simulated's RopeRidingPacket so the server treats the player as riding (no fall damage, hanging animation, etc.), and run per-tick physics.
• W climbs up, S descends, sprint + S slides faster (smooth acceleration up, smooth coast back down).

Plunger ropes

• Two paired LaunchedPlungerEntity projectiles (fired from Simulated's Plunger Launcher) form a rope between them.
• PlungerClimbController iterates ClientLevel.entitiesForRendering() for plungers, computes endpoint positions in world render space (accounting for Sable sublevel transforms so ropes attached to assembled physics objects work), and ray-segment-tests against each pair.
• Embark direction is locked when grabbing the rope. For vertical-ish ropes W goes to the upper end; otherwise W goes toward whichever end the player is facing.
• Slide acceleration and terminal speed scale with sin(angle from horizontal), so vertical plunger ropes accelerate fastest and near-horizontal ropes don't slide beyond the descend baseline.
• The same RopeRidingPacket signal drives the hanging animation in multiplayer.

Plunger ziplines

• Right-clicking a plunger rope while holding a CHAIN_RIDEABLE-tagged item (typically Create's wrench) embarks the player as a zipline rider rather than a climber.
• PlungerZiplineController mirrors Simulated's ZiplineClientManager.ridingTick physics: per-tick damping (v * -0.6, with the along-rope component subtracted), assistance (dir * v.dot(dir) * 0.04), and a spring force pulling the player anchor toward the closest point on the segment. Gravity and normal WASD motion come from vanilla player physics, so a horizontal plunger rope can be walked across as a temporary bridge.
• No steepness gate: plunger ropes are taut straight lines, so any angle is rideable (unlike the strand zipline which gates by maxRopeZiplineAngle).
• Dismount on Sneak, fly toggle, more than 5 ticks grounded, plunger removed/unplunged, or pushed past either endpoint with velocity.dot(dir) > 0.6.

Building

This depends on Simulated's compiled jar. Either:

• Build Simulated locally first (gradlew :simulated:neoforge:build in Simulated-Project/), or
• Drop a built simulated-neoforge-*.jar into ./libs/.

Then run gradlew build.

Controls

To grab on: look at a near-vertical rope strand or a plunger rope within block-interaction range, with an empty main hand, and right-click.

While climbing:

Input	Action
Forward (W)	Climb up (or along the rope toward the locked forward end on plunger ropes)
Back (S)	Descend
Sprint + Back	Slide: accelerates from descend speed up to a sustained slide, coasts to a stop on release
Sneak (Left Shift)	Dismount (let go, no impulse)
Jump (Space)	Jump off with a vanilla-jump-strength upward impulse. When you're at the top of the rope and a block is above, jump instead mantles you onto that block.
Stand on the ground without pressing forward	Auto-dismount after a few ticks
Mouse / camera	Rotates the player around the rope; you hang on the side you're facing
Toggle creative flight	Dismount
Switch off empty hand	Dismount

Sneak-to-dismount matches Simulated's existing on-embark hint ("Press [LEFT SHIFT] to dismount").

Embarking the existing Simulated zipline mode still works the same: look at the rope while holding a CHAIN_RIDEABLE-tagged item (typically Create's wrench) and right-click.

Ziplining a plunger rope

Hold a CHAIN_RIDEABLE-tagged item (typically Create's wrench), look at a plunger rope within block-interaction range, and right-click. You'll latch on and slide under gravity + your own input. Sneak to dismount, or run off either endpoint with enough forward momentum.

Configuration

Server-side config lives at <world>/serverconfig/climbable_ropes-server.toml, generated on first world load. On a dedicated server the operator owns it; in singleplayer the player owns it (per world). Values auto-sync to connected clients on join, so the server is authoritative. Clients can't tweak the file locally to climb faster.

[climbing]

Key	Default	Description
climbSpeed	0.18	Vertical speed when holding forward (blocks/tick).
descendSpeed	0.22	Vertical speed when holding back (blocks/tick).
jumpOffVelocity	0.42	Upward impulse applied when jumping off.

[sliding]

Key	Default	Description
slideSpeed	1.2	Maximum sprint-descend slide speed.
slideAcceleration	0.05	How quickly the slide ramps up.
slideDeceleration	0.04	How quickly the slide eases out after releasing back.

[features]

Key	Default	Description
allowVerticalRopeClimbing	true	Toggle vertical hanging-rope climb.
allowPlungerClimbing	true	Toggle plunger-line climb.
allowPlungerZipline	true	Toggle ziplining along plunger ropes with a CHAIN_RIDEABLE-tagged item.

Toggling a feature off only blocks new embarkations; in-progress climbs finish normally.