Matter and closed paths

[monteiz]

Hello everyone,

I’ve encountered a challenge while working with Phaser 3 and Matter.js that I could use some help with.

I’m currently attempting to create a closed path and add a body to it using Matter.js as the physics engine. My approach involves creating a graphics object for the path and then using Matter to add a body to it. However, I’m facing some issues with alignment.

Here’s a snippet of the code I’ve been working on:

        // the graphics object has been created above
	scnGame.matter.add.gameObject(graphics, {
		vertices,
		isStatic: true,
		render: {
			fillStyle: "#060a19",
			fillColor: "#060a19",
			strokeStyle: "#060a19",
			lineWidth: 1,
		},
		// scale: 15, // ignored
		// restitution: 3 // ignored
		// position // is ignored too
	});

The outcome surprises me because the body doesn’t seem to coincide with the graphics object as expected:

I’ve attempted manual alignment, but properties like scale and position don’t seem to take effect.

I found an example, but it uses specific numbers ([0, 600], [408, 492]) that I don’t quite understand the origin of.

I’m a bit confused about why this misalignment is occurring and how to ensure the body aligns correctly with the graphics object. Any guidance or insights on aligning Matter.js bodies with graphics objects in Phaser 3 would be greatly appreciated!

Thank you in advance for any help or suggestions you can provide.

[monteiz]

I’ve made some progress. By adjusting the camera zoom and playing around with the position (which needs to be a Vector), I’ve observed that the body and the graphics are indeed of the same size. However, they remain misaligned. Here’s the updated code and the current result:

	const obj = scnGame.matter.add.gameObject(graphics, {
		vertices,
		isStatic: true,
		render: {
			fillOpacity: 1,
			fillColor: "#060a19",
			strokeStyle: "#060a19",
			lineThickness: 30,
		},
		position: {
			x: 1900,
			y: 1600,
		},
		// restitution: 3 // ignored
	});

Another issue I’ve encountered is that the body doesn’t seem to participate in collisions.

Any thoughts or suggestions on resolving the alignment discrepancy and enabling collision participation for the Matter body would be immensely helpful.