Fix janky hot air balloon physics

src/main/java/com/minelittlepony/unicopia/client/render/WorldRenderDelegate.java

@@ -167,8 +167,6 @@ public class WorldRenderDelegate {
             return true;
         }
 
-        pony.updateSupportingEntity();
-
         matrices.push();
 
         Entity owner = pony.asEntity();

src/main/java/com/minelittlepony/unicopia/entity/Living.java

@@ -20,7 +20,6 @@ import com.minelittlepony.unicopia.advancement.UCriteria;
 import com.minelittlepony.unicopia.compat.trinkets.TrinketsDelegate;
 import com.minelittlepony.unicopia.entity.behaviour.EntityAppearance;
 import com.minelittlepony.unicopia.entity.behaviour.Guest;
-import com.minelittlepony.unicopia.entity.collision.MultiBoundingBoxEntity;
 import com.minelittlepony.unicopia.entity.damage.MagicalDamageSource;
 import com.minelittlepony.unicopia.entity.duck.LivingEntityDuck;
 import com.minelittlepony.unicopia.entity.effect.CorruptInfluenceStatusEffect;
@@ -67,7 +66,6 @@ import net.minecraft.sound.SoundCategory;
 import net.minecraft.util.Hand;
 import net.minecraft.util.hit.BlockHitResult;
 import net.minecraft.util.math.BlockPos;
-import net.minecraft.util.math.Box;
 import net.minecraft.util.math.Direction;
 import net.minecraft.util.math.MathHelper;
 import net.minecraft.util.math.Vec3d;
@@ -88,14 +86,6 @@ public abstract class Living<T extends LivingEntity> implements Equine<T>, Caste
 
     private boolean invisible = false;
 
-    @Nullable
-    private Entity supportingEntity;
-
-    @Nullable
-    private Vec3d supportPositionOffset;
-    private int ticksOutsideVehicle;
-    private int ticksInVehicle;
-
     @Nullable
     private Caster<?> attacker;
     @Nullable
@@ -109,6 +99,8 @@ public abstract class Living<T extends LivingEntity> implements Equine<T>, Caste
 
     private final Enchantments enchants = addTicker(new Enchantments(this));
     private final ItemTracker armour = addTicker(new ItemTracker(this));
+    //private final Transportation<T> transportation = new Transportation<>(this);
+    private final Transportation<T> transportation = new Transportation<>(this);
 
     protected Living(T entity, TrackedData<NbtCompound> effect) {
         this.entity = entity;
@@ -171,6 +163,10 @@ public abstract class Living<T extends LivingEntity> implements Equine<T>, Caste
         return armour;
     }
 
+    public Transportation<T> getTransportation() {
+        return transportation;
+    }
+
     @Override
     public final T asEntity() {
         return entity;
@@ -202,73 +198,6 @@ public abstract class Living<T extends LivingEntity> implements Equine<T>, Caste
         return vehicle != null && getCarrierId().filter(vehicle.getUuid()::equals).isPresent();
     }
 
-    public boolean setSupportingEntity(@Nullable Entity supportingEntity) {
-        this.supportingEntity = supportingEntity;
-        if (supportingEntity != null) {
-            ticksOutsideVehicle = 0;
-        }
-        return true;
-    }
-
-    @Nullable
-    public Entity getSupportingEntity() {
-        return supportingEntity;
-    }
-
-    public int getTicksInVehicle() {
-        return ticksInVehicle;
-    }
-
-    public void setPositionOffset(@Nullable Vec3d positionOffset) {
-        this.supportPositionOffset = positionOffset;
-    }
-
-    public void updatePositionOffset() {
-        setPositionOffset(supportingEntity == null ? null : entity.getPos().subtract(supportingEntity.getPos()));
-    }
-
-    public void updateRelativePosition(Box box) {
-        if (supportingEntity == null || supportPositionOffset == null) {
-            return;
-        }
-        if (getPhysics().isFlying()) {
-            return;
-        }
-
-        Vec3d newPos = supportingEntity.getPos().add(supportPositionOffset);
-        Vec3d posChange = entity.getPos().subtract(newPos);
-        entity.setPosition(newPos);
-        if (isClient()) {
-            Vec3d newServerPos = LivingEntityDuck.serverPos(entity);
-            if (newServerPos.lengthSquared() != 0) {
-                newServerPos = newServerPos.subtract(posChange);
-                entity.updateTrackedPositionAndAngles(
-                        newServerPos.x, newServerPos.y, newServerPos.z,
-                        entity.getYaw(), entity.getPitch(), 3, true);
-            }
-        } else {
-            entity.updateTrackedPosition(newPos.x, newPos.y, newPos.z);
-        }
-
-        if (!(entity instanceof PlayerEntity)) {
-            entity.lastRenderX = supportingEntity.lastRenderX + supportPositionOffset.x;
-            entity.lastRenderY = supportingEntity.lastRenderY + supportPositionOffset.y;
-            entity.lastRenderZ = supportingEntity.lastRenderZ + supportPositionOffset.z;
-
-            if (entity.getVelocity().length() < 0.1) {
-                LimbAnimationUtil.resetToZero(entity.limbAnimator);
-            }
-        }
-
-        entity.horizontalSpeed = 0;
-        entity.prevHorizontalSpeed = 0;
-        entity.speed = 0;
-        entity.setOnGround(true);
-        entity.verticalCollision = true;
-        entity.groundCollision = true;
-        entity.fallDistance = 0;
-    }
-
     @Override
     public boolean beforeUpdate() {
         if (EffectUtils.getAmplifier(entity, UEffects.PARALYSIS) > 1 && entity.getVelocity().horizontalLengthSquared() > 0) {
@@ -276,44 +205,10 @@ public abstract class Living<T extends LivingEntity> implements Equine<T>, Caste
             updateVelocity();
         }
 
-        updateSupportingEntity();
+        //transportation.updateSupportingEntity();
         return false;
     }
 
-    public void updateSupportingEntity() {
-        if (supportingEntity != null) {
-            Box ownBox = entity.getBoundingBox()
-                    .stretch(entity.getVelocity())
-                    .expand(0.1, 0.5, 0.1)
-                    .stretch(supportingEntity.getVelocity().multiply(-2));
-
-            MultiBoundingBoxEntity.getBoundingBoxes(supportingEntity).stream()
-            .filter(box -> box.stretch(supportingEntity.getVelocity()).expand(0, 0.5, 0).intersects(ownBox))
-            .findFirst()
-            .ifPresentOrElse(box -> {
-                ticksOutsideVehicle = 0;
-                if (supportPositionOffset == null) {
-                    updatePositionOffset();
-                } else {
-                    updateRelativePosition(box);
-                }
-                entity.setOnGround(true);
-                entity.verticalCollision = true;
-                entity.groundCollision = true;
-            }, () -> {
-                // Rubberband passengers to try and prevent players falling out when the velocity changes suddenly
-                if (ticksOutsideVehicle++ > 30) {
-                    supportingEntity = null;
-                    supportPositionOffset = null;
-                    Unicopia.LOGGER.info("Entity left vehicle");
-                } else {
-                    supportPositionOffset = supportPositionOffset.multiply(0.25, 1, 0.25);
-                }
-            });
-        }
-
-    }
-
     @Override
     public void tick() {
         tickers.forEach(Tickable::tick);
@@ -358,13 +253,7 @@ public abstract class Living<T extends LivingEntity> implements Equine<T>, Caste
 
         updateDragonBreath();
 
-        if (ticksOutsideVehicle == 0) {
+        transportation.tick();
-            updatePositionOffset();
-
-            ticksInVehicle++;
-        } else {
-            ticksInVehicle = 0;
-        }
     }
 
     public void updateAttributeModifier(UUID id, EntityAttribute attribute, float desiredValue, Float2ObjectFunction<EntityAttributeModifier> modifierSupplier, boolean permanent) {

src/main/java/com/minelittlepony/unicopia/entity/Transportation.java

@@ -0,0 +1,141 @@
+package com.minelittlepony.unicopia.entity;
+
+import java.util.ArrayList;
+import java.util.List;
+import org.jetbrains.annotations.Nullable;
+
+import com.minelittlepony.unicopia.advancement.UCriteria;
+import com.minelittlepony.unicopia.entity.collision.MultiBoundingBoxEntity;
+import com.minelittlepony.unicopia.entity.duck.EntityDuck;
+import com.minelittlepony.unicopia.entity.mob.AirBalloonEntity;
+import com.minelittlepony.unicopia.util.Tickable;
+
+import net.minecraft.block.ShapeContext;
+import net.minecraft.entity.Entity;
+import net.minecraft.entity.LivingEntity;
+import net.minecraft.entity.MovementType;
+import net.minecraft.util.math.Box;
+import net.minecraft.util.math.MathHelper;
+import net.minecraft.util.math.Vec3d;
+import net.minecraft.util.shape.VoxelShape;
+import net.minecraft.world.event.GameEvent;
+
+public class Transportation<T extends LivingEntity> implements Tickable {
+
+    private final Living<T> living;
+
+    @Nullable
+    private MultiBoundingBoxEntity vehicle;
+    @Nullable
+    private Entity vehicleEntity;
+    @Nullable
+    private Box vehicleBox;
+
+    private int ticksInVehicle;
+
+    private Vec3d lastVehiclePosition = Vec3d.ZERO;
+
+    Transportation(Living<T> living) {
+        this.living = living;
+    }
+
+    public <E extends Entity & MultiBoundingBoxEntity> void setVehicle(@Nullable E vehicle) {
+        this.vehicle = vehicle;
+        this.vehicleEntity = vehicle;
+        updatePreviousPosition();
+    }
+
+    @Override
+    public void tick() {
+        if (vehicle != null) {
+            ticksInVehicle++;
+        } else {
+            ticksInVehicle = 0;
+        }
+
+        if (ticksInVehicle > 20 && vehicle instanceof AirBalloonEntity) {
+            UCriteria.RIDE_BALLOON.trigger(living.asEntity());
+        }
+    }
+
+    public void updatePreviousPosition() {
+        vehicleBox = getVehicleBox();
+        lastVehiclePosition = vehicleEntity == null ? Vec3d.ZERO : vehicleEntity.getPos();
+        Entity entity = living.asEntity();
+        if (vehicleBox != null && living.asEntity().getBoundingBox().intersects(vehicleBox.expand(0.001, 0.5001, 0.001))) {
+            entity.setOnGround(true);
+            entity.onLanding();
+            entity.verticalCollision = true;
+            entity.groundCollision = true;
+            entity.velocityDirty = true;
+            entity.velocityModified = true;
+        }
+    }
+
+    public void onMove(MovementType movementType) {
+        if (vehicleBox == null || vehicleEntity == null) {
+            return;
+        }
+
+        Entity entity = living.asEntity();
+
+        Box passengerBox = entity.getBoundingBox().expand(0.001);
+        Vec3d vehicleMovement = vehicleEntity.getPos().subtract(lastVehiclePosition);
+
+        List<VoxelShape> shapes = new ArrayList<>();
+        vehicle.getCollissionShapes(ShapeContext.of(entity), shapes::add);
+        vehicleMovement = vehicleMovement.add(vehicleEntity.getVelocity());
+        vehicleMovement = Entity.adjustMovementForCollisions(entity, vehicleMovement, passengerBox, entity.getWorld(), shapes);
+
+        Vec3d newPos = entity.getPos().add(vehicleMovement);
+
+        if (!vehicleEntity.isOnGround()) {
+            // surface check to prevent the player from floating
+            if (newPos.getY() > vehicleBox.minY + 0.1 || newPos.getY() < vehicleBox.minY + 0.1) {
+                newPos = new Vec3d(newPos.getX(), vehicleBox.minY + 0.01, newPos.getZ());
+            }
+            // containment checks to prevent the player from falling out of the basket when in flight
+            if (newPos.getY() < vehicleEntity.getPos().getY() + 3) {
+                double maxDeviation = 0.1;
+                double z = MathHelper.clamp(newPos.getZ(), vehicleBox.minZ + maxDeviation, vehicleBox.maxZ - maxDeviation);
+                double x = MathHelper.clamp(newPos.getX(), vehicleBox.minX + maxDeviation, vehicleBox.maxX - maxDeviation);
+
+                newPos = new Vec3d(x, newPos.getY(), z);
+            }
+
+            entity.setPosition(newPos);
+            entity.updateTrackedPosition(newPos.x, newPos.y, newPos.z);
+            entity.setVelocity(Vec3d.ZERO);
+        }
+
+        entity.setOnGround(true);
+        entity.onLanding();
+        entity.verticalCollision = true;
+        entity.groundCollision = true;
+
+        if (entity.distanceTraveled > ((EntityDuck)entity).getNextStepSoundDistance()) {
+            entity.distanceTraveled -= 0.5;
+            entity.playSound(vehicle.getWalkedOnSound(entity.getY()), 0.5F, 1);
+            if (!entity.isSneaky()) {
+                entity.getWorld().emitGameEvent(entity, GameEvent.STEP, entity.getBlockPos());
+            }
+        }
+    }
+
+    @Nullable
+    private Box getVehicleBox() {
+        if (vehicle == null) {
+            return null;
+        }
+
+        Box entityBox = living.asEntity().getBoundingBox().stretch(living.asEntity().getVelocity());
+        for (Box box : vehicle.getGravityZoneBoxes()) {
+            if (entityBox.intersects(box.expand(0.001).stretch(vehicleEntity.getVelocity().multiply(1)))) {
+                return box;
+            }
+        }
+
+        setVehicle(null);
+        return null;
+    }
+}

src/main/java/com/minelittlepony/unicopia/entity/collision/MultiBoundingBoxEntity.java

@@ -1,13 +1,37 @@
 package com.minelittlepony.unicopia.entity.collision;
 
 import java.util.List;
+import java.util.Map;
+import java.util.function.Consumer;
+import java.util.stream.Stream;
 
+import com.minelittlepony.unicopia.entity.collision.EntityCollisions.ComplexCollidable;
+
+import net.minecraft.block.ShapeContext;
 import net.minecraft.entity.Entity;
+import net.minecraft.sound.SoundEvent;
 import net.minecraft.util.math.Box;
+import net.minecraft.util.shape.VoxelShape;
+import net.minecraft.util.shape.VoxelShapes;
 
-public interface MultiBoundingBoxEntity {
+public interface MultiBoundingBoxEntity extends ComplexCollidable {
     List<Box> getBoundingBoxes();
 
+    default List<Box> getGravityZoneBoxes() {
+        return getBoundingBoxes();
+    }
+
+    Map<Box, List<Entity>> getCollidingEntities(Stream<Box> boundingBoxes);
+
+    SoundEvent getWalkedOnSound(double y);
+
+    @Override
+    default void getCollissionShapes(ShapeContext context, Consumer<VoxelShape> output) {
+        for (Box box : getBoundingBoxes()) {
+            output.accept(VoxelShapes.cuboid(box));
+        }
+    }
+
     static List<Box> getBoundingBoxes(Entity entity) {
         return entity instanceof MultiBoundingBoxEntity multi ? multi.getBoundingBoxes() : List.of(entity.getBoundingBox());
     }

src/main/java/com/minelittlepony/unicopia/entity/mob/AirBalloonEntity.java

@@ -13,7 +13,9 @@ import net.minecraft.item.ItemStack;
 import net.minecraft.item.Items;
 import net.minecraft.nbt.NbtCompound;
 import net.minecraft.particle.ParticleTypes;
+import net.minecraft.predicate.entity.EntityPredicates;
 import net.minecraft.registry.RegistryKey;
+import net.minecraft.sound.SoundEvent;
 import net.minecraft.util.ActionResult;
 import net.minecraft.util.Hand;
 import net.minecraft.util.Identifier;
@@ -22,20 +24,22 @@ import net.minecraft.util.function.ValueLists;
 import net.minecraft.util.math.*;
 import net.minecraft.util.math.random.Random;
 import net.minecraft.util.shape.VoxelShape;
-import net.minecraft.util.shape.VoxelShapes;
 import net.minecraft.world.World;
 import net.minecraft.world.event.GameEvent;
 
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
-import java.util.HashSet;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 import java.util.Objects;
-import java.util.Set;
+import java.util.function.Function;
-import java.util.function.Consumer;
 import java.util.function.IntFunction;
+import java.util.function.Predicate;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
 import org.jetbrains.annotations.Nullable;
 
 import com.minelittlepony.unicopia.EquineContext;
@@ -47,7 +51,6 @@ import com.minelittlepony.unicopia.entity.MagicImmune;
 import com.minelittlepony.unicopia.entity.collision.EntityCollisions;
 import com.minelittlepony.unicopia.entity.collision.MultiBoundingBoxEntity;
 import com.minelittlepony.unicopia.entity.collision.MultiBox;
-import com.minelittlepony.unicopia.entity.duck.EntityDuck;
 import com.minelittlepony.unicopia.item.BasketItem;
 import com.minelittlepony.unicopia.item.HotAirBalloonItem;
 import com.minelittlepony.unicopia.item.UItems;
@@ -61,13 +64,14 @@ public class AirBalloonEntity extends MobEntity implements EntityCollisions.Comp
     private static final TrackedData<String> BASKET_TYPE = DataTracker.registerData(AirBalloonEntity.class, TrackedDataHandlerRegistry.STRING);
     private static final TrackedData<Integer> BALLOON_DESIGN = DataTracker.registerData(AirBalloonEntity.class, TrackedDataHandlerRegistry.INTEGER);
 
+    private static final Predicate<Entity> RIDER_PREDICATE = EntityPredicates.EXCEPT_SPECTATOR.and(e -> {
+        return !(e instanceof PlayerEntity p && p.getAbilities().flying);
+    });
+
     private boolean prevBoosting;
     private int prevInflation;
-    private Vec3d oldPosition = Vec3d.ZERO;
     private Vec3d manualVelocity = Vec3d.ZERO;
 
-    private int ticksFlying;
-
     public AirBalloonEntity(EntityType<? extends AirBalloonEntity> type, World world) {
         super(type, world);
         intersectionChecked = true;
@@ -80,12 +84,12 @@ public class AirBalloonEntity extends MobEntity implements EntityCollisions.Comp
         dataTracker.startTracking(ASCENDING, false);
         dataTracker.startTracking(BOOSTING, 0);
         dataTracker.startTracking(INFLATION, 0);
-        dataTracker.startTracking(BASKET_TYPE, "");
+        dataTracker.startTracking(BASKET_TYPE, BasketType.DEFAULT.id().toString());
         dataTracker.startTracking(BALLOON_DESIGN, 0);
     }
 
     public BasketType getBasketType() {
-        return BasketType.REGISTRY.get(Identifier.tryParse(dataTracker.get(BASKET_TYPE)));
+        return BasketType.of(dataTracker.get(BASKET_TYPE));
     }
 
     public void setBasketType(BasketType type) {
@@ -144,14 +148,6 @@ public class AirBalloonEntity extends MobEntity implements EntityCollisions.Comp
         return hasBalloon() && hasBurner() && getInflation() >= getMaxInflation();
     }
 
-    @Override
-    public List<Box> getBoundingBoxes() {
-        if (hasBalloon() && getInflation(1) > 0.999F) {
-            return List.of(getInteriorBoundingBox(), getBalloonBoundingBox());
-        }
-        return List.of(getInteriorBoundingBox());
-    }
-
     @Override
     public void tick() {
         setAir(getMaxAir());
@@ -248,86 +244,12 @@ public class AirBalloonEntity extends MobEntity implements EntityCollisions.Comp
         }
 
         prevBoosting = boosting;
-        oldPosition = getPos();
 
         if (getFireTicks() > 0) {
             setFireTicks(1);
         }
 
-        if (!isOnGround() && (isAirworthy() || isSubmergedInWater() || isLeashed())) {
-            ticksFlying++;
-        } else {
-            ticksFlying = 0;
-        }
-
-        updatePassengers(false);
         super.tick();
-        setBoundingBox(MultiBox.of(getBoundingBox(), getBoundingBoxes()));
-    }
-
-    private void updatePassengers(boolean move) {
-        Set<Entity> alreadyTicked = new HashSet<>();
-        for (Box box : getBoundingBoxes()) {
-            for (Entity e : getWorld().getOtherEntities(this, box.stretch(getVelocity().multiply(-1)).expand(0, 0.5, 0))) {
-
-                if (e instanceof PlayerEntity p && p.getAbilities().flying) {
-                    continue;
-                }
-
-                if (!alreadyTicked.add(e)) {
-                    continue;
-                }
-
-                updatePassenger(e, box, e.getY() > getY() + 3);
-            }
-        }
-    }
-
-    private void updatePassenger(Entity e, Box box, boolean inBalloon) {
-
-        if (e instanceof AirBalloonEntity) {
-            return;
-        }
-
-        if (ticksFlying > 0) {
-            if (Living.getOrEmpty(e).filter(living -> !living.setSupportingEntity(this)).isPresent()) {
-                return;
-            }
-
-            Vec3d vel = getVelocity();
-
-            double height = box.getYLength();
-
-            if (height < 3 || e.getBoundingBox().minY > box.minY + height / 2D) {
-                if (vel.y > 0 && e.getBoundingBox().minY < box.maxY + 0.02) {
-                    e.setPos(e.getX(), box.maxY, e.getZ());
-                    e.setOnGround(true);
-                }
-                if (vel.y < 0 && e.getBoundingBox().minY > box.maxY) {
-                    e.setPos(e.getX(), box.maxY, e.getZ());
-                    e.setOnGround(true);
-                }
-            }
-
-            Living.getOrEmpty(e).ifPresent(living -> {
-                living.setPositionOffset(e.getPos().subtract(oldPosition));
-                living.updateRelativePosition(box);
-
-                if (ticksFlying > 20 && living.getTicksInVehicle() > 20) {
-                    UCriteria.RIDE_BALLOON.trigger(e);
-                }
-            });
-        }
-
-        if (getWorld().isClient) {
-            if (e.distanceTraveled > ((EntityDuck)e).getNextStepSoundDistance()) {
-                e.distanceTraveled--;
-                e.playSound(inBalloon ? USounds.ENTITY_HOT_AIR_BALLOON_STEP : USounds.ENTITY_HOT_AIR_BALLOON_BASKET_STEP, 0.5F, 1);
-                if (!e.isSneaky()) {
-                    getWorld().emitGameEvent(e, GameEvent.STEP, getBlockPos());
-                }
-            }
-        }
     }
 
     @Override
@@ -459,12 +381,16 @@ public class AirBalloonEntity extends MobEntity implements EntityCollisions.Comp
     }
 
     @Override
-    protected void fall(double heightDifference, boolean onGround, BlockState state, BlockPos landedPosition) {
+    public Race getSpecies() {
+        return Race.UNSET;
     }
 
     @Override
-    public Race getSpecies() {
+    public SoundEvent getWalkedOnSound(double y) {
-        return Race.UNSET;
+        if (y >= getBalloonBoundingBox().minY) {
+            return USounds.ENTITY_HOT_AIR_BALLOON_STEP;
+        }
+        return USounds.ENTITY_HOT_AIR_BALLOON_BASKET_STEP;
     }
 
     @Override
@@ -497,6 +423,18 @@ public class AirBalloonEntity extends MobEntity implements EntityCollisions.Comp
                     move(MovementType.SELF, getVelocity());
                     setVelocity(getVelocity().multiply(slipperyness));
                 }
+            } else {
+                Map<Box, List<Entity>> collidingEntities = getCollidingEntities(getBoundingBoxes().stream());
+
+                for (Map.Entry<Box, List<Entity>> passengers : collidingEntities.entrySet()) {
+                    for (Entity passenger : passengers.getValue()) {
+                        Living<?> living = Living.living(passenger);
+                        if (living != null) {
+                            living.getTransportation().setVehicle(this);
+                        }
+
+                    }
+                }
             }
             updateLimbs(false);
         }
@@ -507,17 +445,22 @@ public class AirBalloonEntity extends MobEntity implements EntityCollisions.Comp
         return false;
     }
 
+    @Override
+    protected Box calculateBoundingBox() {
+        return MultiBox.of(super.calculateBoundingBox(), getBoundingBoxes());
+    }
+
     @Override
     public Box getVisibilityBoundingBox() {
         if (hasBalloon()) {
-            return MultiBox.unbox(getBoundingBox()).union(getBalloonBoundingBox());
+            return getBalloonBoundingBox().withMinY(getY());
         }
-        return MultiBox.unbox(getBoundingBox());
+        return getInteriorBoundingBox();
     }
 
     protected Box getInteriorBoundingBox() {
         Box box = MultiBox.unbox(getBoundingBox());
-        return box.withMinY(box.minY - 0.2).contract(0.2, 0, 0.2);
+        return box.withMinY(box.minY - 0.05).contract(0.15, 0, 0.15);
     }
 
     protected Box getBalloonBoundingBox() {
@@ -528,34 +471,96 @@ public class AirBalloonEntity extends MobEntity implements EntityCollisions.Comp
     }
 
     @Override
-    public void getCollissionShapes(ShapeContext context, Consumer<VoxelShape> output) {
+    public List<Box> getGravityZoneBoxes() {
+        Box balloon = getBalloonBoundingBox().expand(0.001);
+        Box interior = getInteriorBoundingBox().expand(0.001);
+        return List.of(
+                // interior - basket to top of balloon
+                interior.withMaxY(balloon.minY).withMinY(interior.maxY),
+                // balloon
+                balloon.withMaxY(balloon.maxY + 0.5).withMinY(balloon.maxY)
+        );
 
-        Box box = MultiBox.unbox(getBoundingBox()).expand(0.3, 0, 0.3);
+    }
 
-        double wallheight = box.maxY + 0.7;
+    @Override
-        double wallThickness = 0.7;
+    public List<Box> getBoundingBoxes() {
+        List<Box> boxes = new ArrayList<>();
+        Box box = getInteriorBoundingBox();
+        boxes.add(box);
+
+        double wallheight = box.maxY + 0.72;
+        double wallThickness = 0.2;
 
         if (!getBasketType().isOf(BoatEntity.Type.BAMBOO)) {
             // front left (next to door)
-            output.accept(VoxelShapes.cuboid(new Box(box.minX, box.minY, box.minZ, box.minX + wallThickness + 0.2, wallheight, box.minZ + wallThickness)));
+            boxes.add(new Box(box.minX, box.minY, box.minZ, box.minX + wallThickness + 0.4, wallheight, box.minZ + wallThickness));
             // front right (next to door)
-            output.accept(VoxelShapes.cuboid(new Box(box.maxX - wallThickness - 0.2, box.minY, box.minZ, box.maxX, wallheight, box.minZ + wallThickness)));
+            boxes.add(new Box(box.maxX - wallThickness - 0.4, box.minY, box.minZ, box.maxX, wallheight, box.minZ + wallThickness));
 
             // back
-            output.accept(VoxelShapes.cuboid(new Box(box.minX, box.minY, box.maxZ - wallThickness, box.maxX, wallheight, box.maxZ)));
+            boxes.add(new Box(box.minX, box.minY, box.maxZ - wallThickness, box.maxX, wallheight, box.maxZ));
 
             // left
-            output.accept(VoxelShapes.cuboid(new Box(box.maxX - wallThickness, box.minY, box.minZ, box.maxX, wallheight, box.maxZ)));
+            boxes.add(new Box(box.maxX - wallThickness, box.minY, box.minZ, box.maxX, wallheight, box.maxZ));
             // right
-            output.accept(VoxelShapes.cuboid(new Box(box.minX, box.minY, box.minZ, box.minX + wallThickness, wallheight, box.maxZ)));
+            boxes.add(new Box(box.minX, box.minY, box.minZ, box.minX + wallThickness, wallheight, box.maxZ));
         }
 
-        // top of balloon
+        if (hasBalloon() && getInflation(1) > 0.999F) {
-        if (hasBalloon() && getInflation() > 0) {
+            boxes.add(getBalloonBoundingBox());
-            output.accept(VoxelShapes.cuboid(getBalloonBoundingBox()));
+        }
+        return boxes;
+    }
+
+    @Override
+    public void move(MovementType movementType, Vec3d movement) {
+        Vec3d oldPos = this.getPos();
+        List<Box> boundingBoxes = getGravityZoneBoxes();
+        super.move(movementType, movement);
+        if (movementType == MovementType.SELF) {
+            Vec3d actualMovement = getPos().subtract(oldPos);
+            Map<Box, List<Entity>> collidingEntities = getCollidingEntities(
+                    boundingBoxes.stream().map(box -> box.stretch(actualMovement))
+            );
+
+            for (Map.Entry<Box, List<Entity>> passengers : collidingEntities.entrySet()) {
+                for (Entity passenger : passengers.getValue()) {
+                    movePassenger(passenger, actualMovement);
+                }
+            }
         }
     }
 
+    private void movePassenger(Entity passenger, Vec3d movement) {
+        Living<?> living = Living.living(passenger);
+        if (living != null) {
+            if (living.getPhysics().isGravityNegative()) {
+                movement = movement.multiply(1, -1, 1);
+            }
+            living.getTransportation().setVehicle(this);
+        }
+
+        List<VoxelShape> shapes = new ArrayList<>();
+        getCollissionShapes(ShapeContext.of(passenger), shapes::add);
+        movement = Entity.adjustMovementForCollisions(passenger, movement, passenger.getBoundingBox(), getWorld(), shapes);
+
+        passenger.setPosition(passenger.getPos().add(movement));
+        passenger.updateTrackedPosition(passenger.getX(), passenger.getY(), passenger.getZ());
+    }
+
+    @Override
+    public Map<Box, List<Entity>> getCollidingEntities(Stream<Box> boundingBoxes) {
+        return boundingBoxes.collect(Collectors.toMap(Function.identity(), box -> {
+            return getWorld().getOtherEntities(this, box.expand(0.001).stretch(getVelocity().multiply(1)), RIDER_PREDICATE).stream().distinct().toList();
+        }));
+    }
+
+    @Override
+    protected void fall(double heightDifference, boolean onGround, BlockState state, BlockPos landedPosition) {
+    }
+
+
     @Override
     public void readCustomDataFromNbt(NbtCompound compound) {
         super.readCustomDataFromNbt(compound);
@@ -577,6 +582,10 @@ public class AirBalloonEntity extends MobEntity implements EntityCollisions.Comp
         compound.putInt("inflationAmount", getInflation());
     }
 
+    static boolean isBetween(double value, double min, double max) {
+        return value >= min && value <= max;
+    }
+
     @SuppressWarnings("deprecation")
     public enum BalloonDesign implements StringIdentifiable {
         NONE,
@@ -607,6 +616,7 @@ public class AirBalloonEntity extends MobEntity implements EntityCollisions.Comp
 
     public record BasketType(Identifier id, @Nullable BoatEntity.Type boatType) {
         private static final Map<Identifier, BasketType> REGISTRY = new HashMap<>();
+        public static final BasketType DEFAULT = of(BoatEntity.Type.OAK);
         static {
             Arrays.stream(BoatEntity.Type.values()).forEach(BasketType::of);
         }
@@ -616,7 +626,7 @@ public class AirBalloonEntity extends MobEntity implements EntityCollisions.Comp
         }
 
         public static BasketType of(String name) {
-            Identifier id = Identifier.tryParse(name);
+            Identifier id = name == null || name.isEmpty() ? null : Identifier.tryParse(name);
             if (id == null) {
                 return of(BoatEntity.Type.OAK);
             }

src/main/java/com/minelittlepony/unicopia/mixin/MixinEntity.java

@@ -21,11 +21,13 @@ import com.minelittlepony.unicopia.entity.duck.EntityDuck;
 import net.minecraft.entity.Entity;
 import net.minecraft.entity.EntityType;
 import net.minecraft.entity.ItemEntity;
+import net.minecraft.entity.MovementType;
 import net.minecraft.entity.Entity.PositionUpdater;
 import net.minecraft.entity.Entity.RemovalReason;
 import net.minecraft.fluid.Fluid;
 import net.minecraft.item.ItemStack;
 import net.minecraft.registry.tag.TagKey;
+import net.minecraft.util.math.Vec3d;
 import net.minecraft.world.World;
 
 @Mixin(Entity.class)
@@ -118,4 +120,20 @@ abstract class MixinEntity implements EntityDuck {
             info.setReturnValue(null);
         }
     }
+
+    @Inject(method = "move", at = @At("HEAD"))
+    private void beforeMove(MovementType movementType, Vec3d movement, CallbackInfo info) {
+        Living<?> living = Living.living((Entity)(Object)this);
+        if (living != null) {
+            living.getTransportation().updatePreviousPosition();
+        }
+    }
+
+    @Inject(method = "move", at = @At("RETURN"))
+    private void afterMove(MovementType movementType, Vec3d movement, CallbackInfo info) {
+        Living<?> living = Living.living((Entity)(Object)this);
+        if (living != null) {
+            living.getTransportation().onMove(movementType);
+        }
+    }
 }