Crear un circulo con sprint internos que colisionen

Quisiera que alguien pudiera ayudarme. me gustaria crear un circulo y dentro de el colocar varios sprites que colisicionen entre si y no se salgan del circulo…

ya he intentado hacerlo con contenedor. con graficos y con imagenes pero no logro hacerlo.

image

Hi, I don’t know either how to do a physics circle containing other bouncing physics, maybe someone with more knowledge on phaser physics.
I was just playing around and this is just an idea on how to create that circle if it helps…

var circle = new Phaser.Geom.Circle(400, 300, 300);
var circle2 = new Phaser.Geom.Circle(400, 300, 290);
var points = circle.getPoints(64);
var points2 = circle2.getPoints(64);
var circlebody = "";
for (var i = 0; i < points.length; i++) {
  circlebody += points[i].x + " " + points[i].y + " ";
}
for (var j = points2.length - 1; j >= 0; j--) {
  circlebody += points2[j].x + " " + points2[j].y + " ";
}
circlebody += points2[points2.length - 1].x + " " + points2[points2.length - 1].y + " ";
circlebody += points[points.length - 1].x + " " + points[points.length - 1].y + " ";
circlebody += points[0].x + " " + points[0].y;
var poly = this.add.polygon(400, 300, circlebody, 0xffffff, 1);
this.matter.add.gameObject(poly, { shape: { type: "fromVerts", verts: circlebody, flagInternal: true } });