git clone https://github.com/Creators-of-Aeronautics/Simulated-Project.git
cd Simulated-Project
./gradlew build

# Start a development client
./gradlew runClient

# Start a development server
./gradlew runServer

# Generate IDE run configurations (IntelliJ)
./gradlew genIntellijRuns

Simulated-Project/
├── simulated/          # Core mod — assembly, physics API
├── aeronautics/        # Flying contraptions submod
├── offroad/            # Land vehicle submod
├── common/             # Shared utilities across submods
└── build.gradle        # Multi-project Gradle build

import com.simulated.api.force.IForceProvider;
import com.simulated.api.contraption.SimulatedContraption;
import net.minecraft.core.BlockPos;
import net.minecraft.world.level.Level;
import org.joml.Vector3f;

public class MyThrusterBlock extends Block implements IForceProvider {

    public MyThrusterBlock(Properties properties) {
        super(properties);
    }

    @Override
    public Vector3f getForce(SimulatedContraption contraption, BlockPos localPos, Level level) {
        // Return force vector in world space (Newtons equivalent)
        // Positive Y = upward lift, positive Z = forward thrust
        float thrustMagnitude = 500.0f;
        return new Vector3f(0, 0, thrustMagnitude);
    }

    @Override
    public Vector3f getTorque(SimulatedContraption contraption, BlockPos localPos, Level level) {
        // Torque applied around center of mass (optional)
        return new Vector3f(0, 0, 0);
    }
}

import net.neoforged.bus.api.IEventBus;
import net.neoforged.neoforge.registries.DeferredRegister;
import net.minecraft.core.registries.BuiltInRegistries;
import net.minecraft.world.level.block.Block;
import net.neoforged.neoforge.registries.DeferredHolder;

public class MyModBlocks {

    public static final DeferredRegister<Block> BLOCKS =
        DeferredRegister.create(BuiltInRegistries.BLOCK, "mymod");

    public static final DeferredHolder<Block, MyThrusterBlock> MY_THRUSTER =
        BLOCKS.register("my_thruster", () -> new MyThrusterBlock(
            Block.Properties.of().strength(2.0f)
        ));

    public static void register(IEventBus eventBus) {
        BLOCKS.register(eventBus);
    }
}

import com.simulated.api.contraption.SimulatedContraption;
import com.simulated.api.contraption.SimulatedContraptionHandler;
import net.minecraft.world.entity.Entity;
import net.minecraft.world.level.Level;
import net.minecraft.world.phys.Vec3;

public class ContraptionUtils {

    /**
     * Get the simulated contraption an entity is riding, if any.
     */
    public static SimulatedContraption getRiddenContraption(Entity entity) {
        return SimulatedContraptionHandler.getContraptionForEntity(entity);
    }

    /**
     * Apply an impulse to a contraption's physics body directly.
     */
    public static void applyImpulse(SimulatedContraption contraption, Vec3 impulse) {
        contraption.getPhysicsBody().applyImpulse(
            new org.joml.Vector3f(
                (float) impulse.x,
                (float) impulse.y,
                (float) impulse.z
            )
        );
    }
}

import com.simulated.api.event.ContraptionAssembleEvent;
import com.simulated.api.event.ContraptionDisassembleEvent;
import net.neoforged.bus.api.SubscribeEvent;
import net.neoforged.fml.common.EventBusSubscriber;

@EventBusSubscriber(modid = "mymod")
public class ContraptionEventHandler {

    @SubscribeEvent
    public static void onAssemble(ContraptionAssembleEvent event) {
        SimulatedContraption contraption = event.getContraption();
        // e.g., calculate custom mass modifier
        float customMass = contraption.getMass() * 0.8f;
        contraption.setMassOverride(customMass);

        System.out.println("Contraption assembled with " +
            contraption.getBlocks().size() + " blocks.");
    }

    @SubscribeEvent
    public static void onDisassemble(ContraptionDisassembleEvent event) {
        // Cleanup any custom data attached to this contraption
        MyContraptionData.remove(event.getContraption().getId());
    }
}

// Example: Redstone-controlled pitch adjustment via a custom block entity
public class FlightControllerBlockEntity extends BlockEntity {

    public FlightControllerBlockEntity(BlockPos pos, BlockState state) {
        super(MyModBlockEntities.FLIGHT_CONTROLLER.get(), pos, state);
    }

    public void applyPitchInput(SimulatedContraption contraption, float pitchDelta) {
        // Torque around the X-axis to pitch the vehicle
        org.joml.Vector3f torque = new org.joml.Vector3f(pitchDelta * 100f, 0, 0);
        contraption.getPhysicsBody().applyTorqueImpulse(torque);
    }
}

# simulated-common.toml

[physics]
  # Physics simulation tick rate (ticks per second, default 20)
  simulationRate = 20
  # Maximum contraption block count before performance warnings
  maxContraptionSize = 2048
  # Enable contraption–contraption collision
  contraptionCollision = true

[aeronautics]
  # Propeller force multiplier
  propellerForceScale = 1.0
  # Hot air buoyancy multiplier
  hotAirBuoyancyScale = 1.0

[offroad]
  # Wheel traction coefficient
  wheelTraction = 0.85
  # Maximum vehicle speed (blocks/second)
  maxVehicleSpeed = 40.0

// In your lang JSON: src/main/resources/assets/mymod/lang/en_us.json
{
  "block.mymod.my_thruster": "Hyperdrive Thruster",
  "block.mymod.my_thruster.tooltip": "Applies directional thrust to assembled contraptions.",
  "mymod.contraption.overloaded": "Contraption mass exceeds safe limits!"
}

@Override
public Vector3f getForce(SimulatedContraption contraption, BlockPos localPos, Level level) {
    // Only provide thrust if a fuel item is present in an adjacent chest
    BlockEntity adjacent = level.getBlockEntity(localPos.above());
    if (adjacent instanceof net.minecraft.world.level.block.entity.ChestBlockEntity chest) {
        boolean hasFuel = !chest.isEmpty(); // simplified check
        if (hasFuel) {
            return new Vector3f(0, 0, 800.0f);
        }
    }
    return new Vector3f(0, 0, 0);
}

@Override
public Vector3f getForce(SimulatedContraption contraption, BlockPos localPos, Level level) {
    // Scale thrust with Create rotational speed at this block's position
    float rpm = contraption.getRotationalSpeedAt(localPos);
    float thrust = rpm * 2.5f; // tune this constant for your use case
    return new Vector3f(0, 0, Math.min(thrust, 2000.0f)); // cap at max
}

import java.util.HashMap;
import java.util.Map;
import java.util.UUID;

public class MyContraptionData {
    private static final Map<UUID, Float> fuelLevels = new HashMap<>();

    public static float getFuel(UUID contraptionId) {
        return fuelLevels.getOrDefault(contraptionId, 100.0f);
    }

    public static void consumeFuel(UUID contraptionId, float amount) {
        float current = getFuel(contraptionId);
        fuelLevels.put(contraptionId, Math.max(0, current - amount));
    }

    public static void remove(UUID contraptionId) {
        fuelLevels.remove(contraptionId);
    }
}

dependencies {
    // NeoForge
    implementation "net.neoforged:neoforge:${neoforge_version}"

    // Create mod (via cursemaven or modrinth maven)
    implementation fg.deobf("com.simibubi.create:create-${minecraft_version}:${create_version}:slim") {
        transitive = false
    }

    // Create Simulated API (once published to maven)
    implementation "com.aeronautics:simulated-api:${simulated_version}"
}