Vehicles, Ships & Drones

Dynamic Moving Perches & Autonomous Quadcopter Docking

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Game worlds are full of dynamic movement: pirate ships rolling on ocean waves, trains speeding across deserts, hanging ropes swinging in breezes, and autonomous drones docking onto mobile command rovers.

PERCH handles moving perches with relative-coordinate stability and momentum inheritance.

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1. Setting Up a Moving Perch

Follow these steps to author a landing spot on any moving object:

Moving Ship / Vehicle Transform
├── Rigidbody (Kinematic or Dynamic)
└── Railing GameObject
    ├── BoxCollider (Physical Support Collider)
    └── PerchSpot (Parented to the moving object)
        └── PerchSlot (Configured with local contact coordinates)

1. Parenting: Attach the PerchSpot component directly to the moving transform (or a child transform within its hierarchy).
2. Assign Support Collider: Drag the platform’s physical collider into the slot’s Support Collider field.
3. Verify Uniform Scale: Ensure the moving parent maintains uniform scale (1, 1, 1). Non-uniform scale can distort contact orientation.

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2. Autonomous Drone & Quadcopter Setup

Drones operate under fundamentally different flight mechanics than winged birds: they do not glide or flare; they descend vertically and spin down their rotors upon touchdown.

Step 1: Creature Profile Configuration

1. In the drone’s PerchCreatureProfile:
   • Set Flight Style to HoverDescent.
   • Set Touchdown Envelope to vertical descent ($80^\circ - 90^\circ$).
   • Set Approach Speed to $1.5\text{ m/s}$.

Step 2: Contact Pad Configuration

1. On the landing dock, set the PerchSlot Contact Mode to Patch.
2. Define the patch dimensions (e.g. $1.0\text{m} \times 1.0\text{m}$) matching the pad surface.

Step 3: Rotor Spin-Down Setup

1. On the drone root, add PerchProceduralAnimationDriver.
2. Assign the propeller transforms to the Rotor Transforms array.
3. Set Max Rotor RPM (e.g., 1200).
4. Touchdown Behavior: As the drone lands, the driver automatically decelerates rotor RPM to zero over $0.5\text{s}$. Upon takeoff, rotors spool up to full RPM before the drone lifts off.

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3. Platform Velocity Handover

When a creature takes off from a fast-moving vehicle (e.g., a train traveling at $15\text{ m/s}$), standard AI will drop the creature to zero world velocity, creating a jarring visual pop where the bird appears to get thrown backward.

PERCH’s departure contract automatically calculates: \(\mathbf{V}_{\text{exit}} = \mathbf{V}_{\text{launch}} + \mathbf{V}_{\text{platform}}\)

The creature carries the vehicle’s momentum smoothly into free flight, creating natural, physically believable motion.