---
title: "Matter Platformer with Dynamic Tile Modification"
description: "Demonstrates how to modify a Matter-enabled Tilemap at runtime, including updating existing tile collision shapes and adding new physics-enabled tiles to build a bridge."
phaser: "4.1.0"
size: "800x600"
files: 1
url: https://phaser.io/oss/examples/v4.1.0/tilemap/collision/view/matter-platformer-modify-map
site: Phaser - https://phaser.io
---

> This page is about the open-source Phaser framework, for writing a game's code by hand. To make a game with AI, use Phaser AE (https://phaser.io/): the desk's tools work with Web MCP, and the CLI works with your own coding agent. See "For AI agents: Phaser AE" at the end of this page.

# Matter Platformer with Dynamic Tile Modification

Demonstrates how to modify a Matter-enabled Tilemap at runtime, including updating existing tile collision shapes and adding new physics-enabled tiles to build a bridge.

A Phaser 4.1.0 example in [Tilemap / Collision](https://phaser.io/oss/examples/v4.1.0/tilemap/collision.md). It runs at 800 × 600, and loads its assets from https://cdn.phaserfiles.com/v410. See it running, with its code, at https://phaser.io/oss/examples/v4.1.0/tilemap/collision/view/matter-platformer-modify-map.

To run it, load Phaser 4.1.0 (`https://cdn.jsdelivr.net/npm/phaser@4.1.0/dist/phaser.min.js`), then the file, on a page with a `<div id="game-container">`.

## Code

### matter platformer modify map.js

```js
class Example extends Phaser.Scene
{
    playerController;
    cursors;
    cam;
    smoothedControls;
    map;

    constructor () {
        super({ key: "main" });
    }

    preload ()
    {
        this.load.setBaseURL('https://cdn.phaserfiles.com/v410');
        this.load.tilemapTiledJSON('map', 'assets/tilemaps/maps/matter-platformer-dynamic-example.json');
        this.load.image('kenney_redux_64x64', 'assets/tilemaps/tiles/kenney_redux_64x64.png');
        this.load.spritesheet('player', 'assets/sprites/dude-cropped.png', { frameWidth: 32, frameHeight: 42 });
        this.load.image('box', 'assets/sprites/box-item-boxed.png');
    }

    create ()
    {
        this.map = this.make.tilemap({ key: 'map' });
        const tileset = this.map.addTilesetImage('kenney_redux_64x64');
        const bgLayer = this.map.createLayer('Background Layer', tileset, 0, 0);
        const groundLayer = this.map.createLayer('Ground Layer', tileset, 0, 0);
        const fgLayer = this.map.createLayer('Foreground Layer', tileset, 0, 0).setDepth(1);

        // Set up the layer to have matter bodies. Any colliding tiles will be given a Matter body.
        groundLayer.setCollisionByProperty({ collides: true });
        this.matter.world.convertTilemapLayer(groundLayer);

        this.matter.world.setBounds(this.map.widthInPixels, this.map.heightInPixels);
        this.matter.world.drawDebug = false;

        this.cursors = this.input.keyboard.createCursorKeys();
        this.smoothedControls = new SmoothedHorionztalControl(0.001);

        // The player is a collection of bodies and sensors
        this.playerController = {
            matterSprite: this.matter.add.sprite(0, 0, 'player', 4),
            blocked: {
                left: false,
                right: false,
                bottom: false
            },
            numTouching: {
                left: 0,
                right: 0,
                bottom: 0
            },
            sensors: {
                bottom: null,
                left: null,
                right: null
            },
            time: {
                leftDown: 0,
                rightDown: 0
            },
            lastJumpedAt: 0,
            speed: {
                run: 5,
                jump: 7
            }
        };

        const M = Phaser.Physics.Matter.Matter;
        const w = this.playerController.matterSprite.width;
        const h = this.playerController.matterSprite.height;

        // Move the sensor to player center
        const sx = w / 2;
        const sy = h / 2;

        // The player's body is going to be a compound body.
        const height_fix = 0;
        const playerBody = M.Bodies.rectangle(sx, sy, w * 0.75, h, { chamfer: { radius: 10 } });
        this.playerController.sensors.bottom = M.Bodies.rectangle(sx, h, sx, 5, { isSensor: true });
        this.playerController.sensors.left = M.Bodies.rectangle(sx - w * 0.45, sy, 5, h * 0.25, { isSensor: true });
        this.playerController.sensors.right = M.Bodies.rectangle(sx + w * 0.45, sy, 5, h * 0.25, { isSensor: true });
        const compoundBody = M.Body.create({
            parts: [
                playerBody, this.playerController.sensors.bottom, this.playerController.sensors.left,
                this.playerController.sensors.right
            ],
            restitution: 0.05 // Prevent body from sticking against a wall
        });

        // There is a "Button Press Sensor" polygon in the "Sensors" layer in Tiled. We can use this to
        // map out the "pressable" hitbox for the button.
        const sensor = this.map.findObject('Sensors', function (obj)
        {
            return obj.name === 'Button Press Sensor';
        });
        const center = M.Vertices.centre(sensor.polygon); // Matter places shapes by center of mass
        const sensorBody = this.matter.add.fromVertices(
            sensor.x + center.x, sensor.y + center.y,
            sensor.polygon,
            { isStatic: true, isSensor: true }
        );

        this.playerController.matterSprite
            .setExistingBody(compoundBody)
            .setFixedRotation() // Sets max inertia to prevent rotation
            .setPosition(32, 1000);

        this.cam = this.cameras.main;
        this.cam.setBounds(0, 0, this.map.widthInPixels, this.map.heightInPixels);
        this.smoothMoveCameraTowards(this.playerController.matterSprite);

        this.anims.create({
            key: 'left',
            frames: this.anims.generateFrameNumbers('player', { start: 0, end: 3 }),
            frameRate: 10,
            repeat: -1
        });
        this.anims.create({
            key: 'right',
            frames: this.anims.generateFrameNumbers('player', { start: 5, end: 8 }),
            frameRate: 10,
            repeat: -1
        });
        this.anims.create({
            key: 'idle',
            frames: this.anims.generateFrameNumbers('player', { start: 4, end: 4 }),
            frameRate: 10,
            repeat: -1
        });

        // Use matter events to detect whether the player is touching a surface to the left, right or
        // bottom.

        // Loop over the active colliding pairs and count the surfaces the player is touching.
        this.matter.world.on('collisionstart', function (event)
        {
            for (let i = 0; i < event.pairs.length; i++)
            {
                const bodyA = event.pairs[i].bodyA;
                const bodyB = event.pairs[i].bodyB;
                if ((bodyA === playerBody && bodyB === sensorBody) ||
                    (bodyA === sensorBody && bodyB === playerBody))
                {
                    this.matter.world.remove(sensorBody);

                    const buttonTile = groundLayer.getTileAt(4, 18);

                    // Change the tile to the new index (a "pressed" button tile) and tell the existing
                    // matter body to update itself from the Tiled collision data.
                    buttonTile.index = 93;
                    buttonTile.physics.matterBody.setFromTileCollision();

                    // Animate a bridge of new tiles opening up over the lava.
                    for (let j = 5; j <= 14; j++)
                    {
                        this.time.addEvent({
                            delay: (j - 5) * 50,
                            callback: function (x)
                            {
                                const bridgeTile = groundLayer.putTileAt(12, x, 19);

                                // When creating a new tile that didn't already have a tile body, you
                                // can use the tileBody factory method. See
                                // Phaser.Physics.Matter.TileBody for options. This will default to
                                // adding a body with the Tiled collision data here.
                                this.matter.add.tileBody(bridgeTile);
                            }.bind(this, j)
                        });
                    }
                }
            }
        }, this);

        // Use matter events to detect whether the player is touching a surface to the left, right or
        // bottom.

        // Before matter's update, reset the player's count of what surfaces it is touching.
        this.matter.world.on('beforeupdate', function (event)
        {
            this.playerController.numTouching.left = 0;
            this.playerController.numTouching.right = 0;
            this.playerController.numTouching.bottom = 0;
        }, this);

        // Loop over the active colliding pairs and count the surfaces the player is touching.
        this.matter.world.on('collisionactive', function (event)
        {
            const playerBody = this.playerController.body;
            const left = this.playerController.sensors.left;
            const right = this.playerController.sensors.right;
            const bottom = this.playerController.sensors.bottom;

            for (let i = 0; i < event.pairs.length; i++)
            {
                const bodyA = event.pairs[i].bodyA;
                const bodyB = event.pairs[i].bodyB;

                if (bodyA === playerBody || bodyB === playerBody)
                {
                    continue;
                }
                else if (bodyA === bottom || bodyB === bottom)
                {
                    // Standing on any surface counts (e.g. jumping off of a non-static crate).
                    this.playerController.numTouching.bottom += 1;
                }
                else if ((bodyA === left && bodyB.isStatic) || (bodyB === left && bodyA.isStatic))
                {
                    // Only static objects count since we don't want to be blocked by an object that we
                    // can push around.
                    this.playerController.numTouching.left += 1;
                }
                else if ((bodyA === right && bodyB.isStatic) || (bodyB === right && bodyA.isStatic))
                {
                    this.playerController.numTouching.right += 1;
                }
            }
        }, this);

        // Update over, so now we can determine if any direction is blocked
        this.matter.world.on('afterupdate', function (event)
        {
            this.playerController.blocked.right = this.playerController.numTouching.right > 0 ? true : false;
            this.playerController.blocked.left = this.playerController.numTouching.left > 0 ? true : false;
            this.playerController.blocked.bottom = this.playerController.numTouching.bottom > 0 ? true : false;
        }, this);

        this.input.on('pointerdown', function ()
        {
            this.matter.world.drawDebug = !this.matter.world.drawDebug;
            this.matter.world.debugGraphic.visible = this.matter.world.drawDebug;
        }, this);

        const lines = [
            'Arrow keys to move. Press "Up" to jump.',
            'Press the button!',
            'Click to toggle rendering Matter debug.'
        ];

        const text = this.add.text(16, 16, lines, {
            fontSize: '20px',
            padding: { x: 20, y: 10 },
            backgroundColor: '#ffffff',
            fill: '#000000'
        });
        text.setScrollFactor(0);
    }

    update (time, delta)
    {
        const matterSprite = this.playerController.matterSprite;
        if (!matterSprite) { return; }

        // Player death
        if (matterSprite.y > this.map.heightInPixels)
        {
            matterSprite.destroy();
            this.playerController.matterSprite = null;
            this.restart();
            return;
        }

        // Horizontal movement
        let oldVelocityX;
        let targetVelocityX;
        let newVelocityX;

        if (this.cursors.left.isDown && !this.playerController.blocked.left)
        {
            this.smoothedControls.moveLeft(delta);
            matterSprite.anims.play('left', true);

            // Lerp the velocity towards the max run using the smoothed controls. This simulates a
            // player controlled acceleration.
            oldVelocityX = matterSprite.body.velocity.x;
            targetVelocityX = -this.playerController.speed.run;
            newVelocityX = Phaser.Math.Linear(oldVelocityX, targetVelocityX, -this.smoothedControls.value);

            matterSprite.setVelocityX(newVelocityX);
        }
        else if (this.cursors.right.isDown && !this.playerController.blocked.right)
        {
            this.smoothedControls.moveRight(delta);
            matterSprite.anims.play('right', true);

            // Lerp the velocity towards the max run using the smoothed controls. This simulates a
            // player controlled acceleration.
            oldVelocityX = matterSprite.body.velocity.x;
            targetVelocityX = this.playerController.speed.run;
            newVelocityX = Phaser.Math.Linear(oldVelocityX, targetVelocityX, this.smoothedControls.value);

            matterSprite.setVelocityX(newVelocityX);
        }
        else
        {
            this.smoothedControls.reset();
            matterSprite.anims.play('idle', true);
        }

        // Jumping

        // Add a slight delay between jumps since the sensors will still collide for a few frames after
        // a jump is initiated
        const canJump = (time - this.playerController.lastJumpedAt) > 250;
        if (this.cursors.up.isDown & canJump && this.playerController.blocked.bottom)
        {
            matterSprite.setVelocityY(-this.playerController.speed.jump);
            this.playerController.lastJumpedAt = time;
        }

        this.smoothMoveCameraTowards(matterSprite, 0.9);
    }

    smoothMoveCameraTowards (target, smoothFactor)
    {
        if (smoothFactor === undefined) { smoothFactor = 0; }
        this.cam.scrollX = smoothFactor * this.cam.scrollX + (1 - smoothFactor) * (target.x - this.cam.width * 0.5);
        this.cam.scrollY = smoothFactor * this.cam.scrollY + (1 - smoothFactor) * (target.y - this.cam.height * 0.5);
    }

    restart ()
    {
        this.cam.fade(500, 0, 0, 0);
        this.cam.shake(250, 0.01);

        this.time.addEvent({
            delay: 500,
            callback: function ()
            {
                this.cam.resetFX();
                this.scene.stop();
                this.scene.start('main');
            },
            callbackScope: this
        });
    }

}

// Smoothed horizontal controls helper. This gives us a value between -1 and 1 depending on how long
// the player has been pressing left or right, respectively.
class SmoothedHorionztalControl
{
    constructor (speed)
    {
        this.msSpeed = speed;
        this.value = 0;
    }

    moveLeft (delta)
    {
        if (this.value > 0) { this.reset(); }
        this.value -= this.msSpeed * delta;
        if (this.value < -1) { this.value = -1; }
    }

    moveRight (delta)
    {
        if (this.value < 0) { this.reset(); }
        this.value += this.msSpeed * delta;
        if (this.value > 1) { this.value = 1; }
    }

    reset ()
    {
        this.value = 0;
    }
}

const config = {
    scale: { mode: Phaser.Scale.FIT },
    type: Phaser.AUTO,
    width: 800,
    height: 600,
    backgroundColor: '#000000',
    parent: 'game-container',
    physics: {
        default: 'matter',
        matter: {
            gravity: { y: 1 },
            enableSleep: false,
            debug: true
        }
    },
    scene: Example
};

const game = new Phaser.Game(config);
```

## More in Collision

- [CSV Tilemap with Arcade Physics](https://phaser.io/oss/examples/v4.1.0/tilemap/collision/view/csv-map-arcade-physics.md): Load a tilemap from a CSV file, define colliding tile ranges, and enable Arcade Physics collisions between a player sprite and the map layer. Includes a debug view toggle to visualize collision bounds.
- [Matter Destroy Tile Bodies](https://phaser.io/oss/examples/v4.1.0/tilemap/collision/view/matter-destroy-tile-bodies.md): Demonstrates how to dynamically remove tiles and destroy their associated Matter physics bodies when triggered by player contact. It uses custom Tiled properties to identify specific tiles and handles character movement with a compound Matter body and sensors.
- [Matter Ghost Collisions](https://phaser.io/oss/examples/v4.1.0/tilemap/collision/view/matter-ghost-collisions.md): Demonstrates how to mitigate 'ghost collisions' at tile seams in Matter JS by comparing individual tile bodies with a single large convex body defined via Tiled object layers.
- [Matter Physics Platformer with Wall Jumping](https://phaser.io/oss/examples/v4.1.0/tilemap/collision/view/matter-platformer-with-wall-jumping.md): A comprehensive example of a Matter.js platformer featuring compound bodies and sensors for advanced collision detection. It demonstrates smoothed horizontal movement, wall jumping logic, and converting Tiled tilemaps into physical Matter bodies.
- [Matter Physics Tilemap Collision](https://phaser.io/oss/examples/v4.1.0/tilemap/collision/view/matter.md): Demonstrates how to convert a Tilemap layer into Matter.js physics bodies, supporting both default rectangular bounds and custom collision shapes defined in Tiled.
- [Matter Tilemap Collision Detection](https://phaser.io/oss/examples/v4.1.0/tilemap/collision/view/matter-detect-collision-with-tile.md): Demonstrates how to convert a Tilemap layer into Matter.js physics bodies and detect collisions between sprites and specific tiles using body labels and custom Tiled properties.
- [Multiple Tile Sizes and Collisions](https://phaser.io/oss/examples/v4.1.0/tilemap/collision/view/multiple-tile-sizes.md): Demonstrates how to handle physics collisions across multiple tilemap layers using different tile dimensions (32x32, 64x64, and 32x64) within a single map.
- [Simple Tilemap Collision and Interaction](https://phaser.io/oss/examples/v4.1.0/tilemap/collision/view/simple-map.md): Demonstrates how to set tile-based collisions, use Arcade Physics with a tilemap layer, and filter specific tiles to create interactive pickups that can be removed from the map.
- [Tile Callbacks](https://phaser.io/oss/examples/v4.1.0/tilemap/collision/view/tile-callbacks.md): Learn how to trigger custom functions when a sprite interacts with specific tiles using index-based and location-based callbacks. This example demonstrates collecting items and creating secret passages by modifying collision behavior.
- [Tilemap Overlap Callbacks](https://phaser.io/oss/examples/v4.1.0/tilemap/collision/view/custom-collide-call.md): Demonstrates how to use overlapTiles to detect and handle custom interactions between a physics body and specific tile indices, such as collecting items.
- [Tilemap Spotlight](https://phaser.io/oss/examples/v4.1.0/tilemap/collision/view/tilemap-spotlight.md): Demonstrates a dynamic spotlight effect over a tilemap using a RenderTexture to mask the scene based on the player's position.

---

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