MapObj: placed interactive world objects

MapObj is the catch-all system for placed world objects in Super Mario Galaxy 1. Almost every non-enemy, non-player, non-area object in a level — from coins and power stars to lava geysers and observatory machinery — is a MapObjActor or a class that inherits from it. The MapObj/ directory contains over 310 header files, making it the largest subsystem in the codebase.

MapObjActor — the base class

MapObjActor inherits LiveActor and adds standardized support for rail movement, rotation, breakable models, switch reactions (SwitchA / SwitchB), LOD control, and a three-nerve state machine (Wait → Move → Done).

class MapObjActor : public LiveActor {
public:
    MapObjActor(const char*);
    MapObjActor(const char*, const char*);  // alternate ctor with model name override

    virtual void init(const JMapInfoIter&);
    virtual void initAfterPlacement();
    virtual void appear();
    virtual void kill();
    virtual void control();
    virtual void calcAndSetBaseMtx();

    // Scene-connection and switch setup
    virtual void connectToScene(const MapObjActorInitInfo&);
    virtual void initCaseUseSwitchA(const MapObjActorInitInfo&);
    virtual void initCaseNoUseSwitchA(const MapObjActorInitInfo&);
    virtual void initCaseUseSwitchB(const MapObjActorInitInfo&);
    virtual void initCaseNoUseSwitchB(const MapObjActorInitInfo&);

    // Helpers
    bool isObjectName(const char*) const;
    bool tryCreateBreakModel(const MapObjActorInitInfo&);
    void startMapPartsFunctions();
    void endMapPartsFunctions();
    void pauseMapPartsFunctions();

    // State execute methods
    void exeWait();
    void exeMove();
    void exeDone();

    const char* mObjectName;                    // 0x8C
    LodCtrl* mPlanetLodCtrl;                    // 0x90
    ModelObj* mBloomModel;                      // 0x94
    ModelObj* mModelObj;                        // 0x98
    ProjmapEffectMtxSetter* mMatrixSetter;      // 0x9C
    MapPartsRailMover* mRailMover;              // 0xA0
    MapPartsRotator* mRotator;                  // 0xA4
    MapPartsRailRotator* mRailRotator;          // 0xA8
    MapPartsRailPosture* mRailPosture;          // 0xAC
    MapPartsRailGuideDrawer* mRailGuideDrawer;  // 0xB0
    Nerve* mWaitNrv;  // 0xB8
    Nerve* mMoveNrv;  // 0xBC
    Nerve* mDoneNrv;  // 0xC0
};

MapObjActorInitInfo — initialization descriptor

MapObjActorInitInfo is a plain data struct that sub-classes fill before calling MapObjActor::initialize(). It switches on/off subsystems like the binder, shadow, sensors, rail mover, and rotator without requiring virtual overrides for every combination.

class MapObjActorInitInfo {
public:
    MapObjActorInitInfo();

    void setupHioNode(const char*);
    void setupModelName(const char*);
    void setupConnectToScene();
    void setupBinder(f32, f32);
    void setupEffect(const char*);
    void setupHitSensor();
    void setupShadow(const char*);
    void setupRailMover();
    void setupRotator();
    void setupRailRotator();
    void setupRailPosture();
    void setupNerve(const Nerve*);
    void setupGroupClipping(s32);
    void setupClippingRadius(f32);

    bool mSetDefaultPosition;  // 0x0
    bool mConnectToScene;      // 0x1
    bool mInitBinder;          // 0x2
    bool mHasEffect;           // 0x3
    bool mHasSensors;          // 0x4
    bool mHasShadows;          // 0x5
    bool mCalcGravity;         // 0x6
    bool mProjectMapMtx;       // 0x7
    bool mHasRailMover;        // 0x9
    bool mHasRotator;          // 0xA
    bool mHasRailRotator;      // 0xB
    bool mUsesRailPosture;     // 0xE
    bool mNoUseLOD;            // 0x8D

    const char* mModelName;    // 0x14
    f32 mSensorSize;           // 0x20
    TVec3f mSensorOffset;      // 0x24
    f32 mBinderRadius;         // 0x34
    f32 mBinderCenterY;        // 0x38
    const char* mEffectName;   // 0x3C
    const Nerve* mNerve;       // 0x4C
    f32 mClippingRadius;       // 0x54
    const char* mShadowName;   // 0x78
    f32 mShadowLength;         // 0x7C
};

Object categories

Collectibles

Items the player picks up to gain points, health, or progress.

Class	Object	Notes
`Coin`	Coin	Full state machine: fix, move, hop, spin-drain; tracks `mIsPurpleCoin`
`BlueChip`	Blue chip	Counted variant of coin
`YellowChip`	Yellow chip	Counted variant
`StarPiece`	Star bit	Physics projectile attracted by star pointer
`PowerStar`	Power star	Complex appear demo and `mIsGrandStar` flag
`Note`	Music note	Path-following collectible
`MorphItemObjNeo`	Transformation item	Activates bee/ice/fire modes
`BenefitItemInvincible`	Invincibility star	Timed power-up
`BenefitItemLifeUp`	1-Up mushroom	Extra life collectible
`CoinBox`	Coin box	Spawns coins when struck
`ItemBlock`	? Block	Spawns item on first hit

Switches

Pressure plates and interactive switches that trigger other objects via the switch system.

Class	Object	Notes
`CrystalSwitch`	Crystal switch	Spin-attack activated; rotates on impact
`HipDropSwitch`	Ground-pound switch	Requires hip-drop to activate
`HipDropTimerSwitch`	Timed ground-pound switch	Auto-deactivates
`KeySwitch`	Key switch	Requires a key item
`ScrewSwitch`	Screw switch	Rotated by spin attack
`ScrewSwitchReverse`	Reverse screw switch	Opposite rotation direction
`PicketSwitch`	Picket switch	Step-on activated
`SpinLeverSwitch`	Spin lever	Pull by spinning
`ValveSwitch`	Valve	Turn to open
`ArrowSwitch`	Arrow switch	Directional tile switch
`PTimerSwitch`	P-switch	Classic Mario timed switch
`HitWallTimerSwitch`	Wall-hit timer switch	Activates on collision
`SwitchBox`	Switch box	Destroyable to activate
`DesertLandMoveSwitch`	Sand land switch	Moves terrain segment
`SnowplowSwitch`	Snowplow switch	Pushes snow

Platforms and moving objects

Surfaces the player can stand on, with optional movement along a rail.

Class	Object	Notes
`IceStep`	Ice platform	Slippery surface; also used as a footing on Mario’s ice floor
`AssemblyBlock`	Assembly block	Snaps together via switch
`FallDownBridge`	Collapsing bridge	Falls after delay when stood on
`RailMoveObj`	Generic rail mover	`MapObjActor` subclass for rail-following platforms
`RotateMoveObj`	Rotating platform	`MapObjActor` subclass for rotating objects
`HipDropMoveObj`	Hip-drop platform	Drops on ground-pound
`RevolvingWay`	Revolving walkway	Rotates continuously
`CollapsePlane`	Collapse plane	Crumbles under sustained weight
`RailBlock`	Rail block	Slides along rail between stops
`TimerMoveWall`	Timer-wall	Moves on timed schedule
`WatchTowerRotateStep`	Tower staircase	Rotates around vertical axis
`BattleShipElevator`	Battleship elevator	Vertical lift
`LargeChain`	Chain	Animated decorative chain with physics

Hazards

Environmental objects that damage or kill the player on contact.

class BlackHole : public LiveActor {
public:
    virtual void init(const JMapInfoIter&);
    virtual void attackSensor(HitSensor*, HitSensor*);

    bool isInCubeBox(const TVec3f&) const;
    void exeWait();
    void exeDemo();
    void exeDisappear();

    ModelObj* mBlackHoleModel;     // 0x8C
    ActorCameraInfo* mCameraInfo;  // 0x108
};

Class	Object	Notes
`BlackHole`	Black hole	Pulls Mario in; `isInCubeBox` for cubic variant
`FireBar`	Fire bar	Rotating fire chain (`FireBubble` chain)
`LavaGeyser`	Lava geyser	Periodic lava burst
`SpaceMine`	Spiked mine	Floats on path; contact hazard
`Jiraira`	Spiked ground mine	Proximity-triggered explosion (also in Enemy)
`ElectricBall`	Electric ball	Rolling electric sphere
`ElectricRail`	Electric rail	Rail with periodic pulse
`LavaBreakColumn`	Lava column	Breaks after timed interval
`LavaProminence`	Lava prominence	Eruption of lava arc
`LavaFloater`	Lava floater	Rocks floating on lava
`NeedlePlant`	Needle plant	Spike-hazard foliage
`SandstormBase`	Sandstorm	Wind-push hazard
`Dossun`	Thwomp (also Enemy)	Ceiling-drop hazard

Water and fluid objects

Objects related to water physics, fountains, and the ocean system.

Class	Object	Notes
`Fountain`	Fountain	Vertical water spout
`FountainBig`	Large fountain	Larger variant with extra splash
`OceanWaveFloater`	Ocean wave floater	Follows wave height
`LotusLeaf`	Lily pad	Floats on water surface
`WaterLeakPipe`	Leaky pipe	Sprays directional water stream
`WaterPressure`	Water pressure cannon	Shoots `WaterPressureBullet`
`SpringJetWater`	Spring jet	Underwater upward jet
`SpringWaterFloaterSpot`	Water hover spot	Lifts Mario if in beam
`WhirlPool`	Whirlpool	Spinning current area
`AirBubble`	Air bubble	Replenishes water breath meter
`AirBubbleGenerator`	Bubble generator	Periodically emits `AirBubble`
`BigBubble` / `BigBubbleHolder`	Giant bubble	Transport bubble for Mario
`Shellfish`	Clam	Opens and closes; can contain item

Astro Observatory objects

Objects specific to the hub world, Comet Observatory / Astro Observatory.

Class	Object	Notes
`AstroDome`	Dome building	Each dome leads to a galaxy
`AstroCore`	Observatory core	Central power star socket
`AstroMapBoard`	Map board	Displays galaxy select map
`AstroMapObj`	Generic observatory object	Base for observatory decoration
`AstroOverlookObj`	Overlook object	Scenic decoration near observatory
`AstroDomeAsteroid`	Dome asteroid	Flying rock near domes
`AstroDomeBlueStar`	Blue star	Decorative orbiting star
`AstroDomeComet`	Comet	Fast-moving comet decoration
`AstroDomeOrbit`	Orbit ring	Animated orbit trajectory
`AstroCountDownPlate`	Countdown plate	Displays comet arrival timer
`MiniatureGalaxy`	Miniature galaxy	Small galaxy model in hub

Spin drivers and launch stars

Objects that launch Mario to a new area.

Class	Object	Notes
`SpinDriver`	Launch star	Standard spin-powered launch star
`SuperSpinDriver`	Super launch star	Faster variant
`SpinDriverCamera`	Camera controller	Handles the launch camera cut
`SpinDriverShootPath`	Shoot path	Defines the launch trajectory
`MarioLauncher`	Cannon	Barrel cannon that fires Mario
`WarpPod`	Warp pod	Warp point between galaxy sections
`DashRing`	Dash ring	Boosts Mario’s speed through ring
`PrizeRing`	Prize ring	Spin through to collect star bits
`JumpStand`	Jump panel	Bounces Mario upward
`JumpHole`	Jump hole	Drops Mario to a lower area

Coin — full state machine example

Coin illustrates the level of detail typical in MapObj classes: it has nine distinct nerve states, can appear in multiple ways, and tracks water submersion and purple coin variants.

class Coin : public LiveActor {
public:
    virtual void init(const JMapInfoIter&);
    virtual void appear();
    virtual void calcAndSetBaseMtx();
    virtual bool receiveOtherMsg(u32, HitSensor*, HitSensor*);

    // Appear variants
    void appearFix();
    void appearFixTimer(s32, s32);
    void appearMove(const TVec3f&, const TVec3f&, s32, s32);
    void appearHop(const TVec3f&, const TVec3f&);

    // Nerve execute methods
    void exeNonActive();
    void exeFix();
    void exeFixHide();
    void exeFixTimer();
    void exeMove();
    void exeControled();
    void exeSpinDrained();
    void exeHop();

    CoinHostInfo* mHostInfo;   // 0x8C
    FlashingCtrl* mFlashCtrl;  // 0x90
    PartsModel* mAirBubble;    // 0x94
    TVec3f mDropPosition;      // 0x98
    s32 mCannotTime;           // 0xB4
    bool mIsInWater;           // 0xB8
    bool mIsPurpleCoin;        // 0xBC
    bool mIsNeedBubble;        // 0xBD
};

MapObjActorUtil provides static helpers for starting, stopping, and pausing the rotator and rail mover on any MapObjActor. Use MapObjActorUtil::isRailMoverReachedEnd to check if a moving platform has completed its path, and MapObjActorUtil::startBreak to trigger a breakable object’s destruction sequence.

Core Systems

Game Subsystems

Game Objects

Libraries

MapObj: placed interactive world objects

MapObjActor — the base class

MapObjActorInitInfo — initialization descriptor

Object categories

Coin — full state machine example

Build docs developers (and LLMs) love

Core Systems

Game Subsystems

Game Objects

Libraries

Documentation Index

​MapObjActor — the base class

​MapObjActorInitInfo — initialization descriptor

​Object categories

​Coin — full state machine example

Build docs developers (and LLMs) love

MapObjActor — the base class

MapObjActorInitInfo — initialization descriptor

Object categories

Coin — full state machine example