// a e b sao o centro
	var a = 0;
	var b = 0;

	//coordenadas
	var z =0;

	//angulo

	var teta = 30;  //angulos
	var angulo = (teta*2*Math.PI)/360; //radianos


	//raio

	var r = 1.0;

	this.vertices = [];
	this.indices = [];


	this.vertices.push(r);
	this.vertices.push(0);
	this.vertices.push(z);

	while(angulo < 2*Math.PI){
		this.vertices.push(a+r*Math.cos(angulo));
		this.vertices.push(b+r*Math.sin(angulo));
		this.vertices.push(z);
		angulo = angulo + (teta*2*Math.PI)/360;
	}

	// adicionar o centro

	this.vertices.push(a);
	this.vertices.push(b);
	this.vertices.push(z);


	for(i=1;i <= (this.vertices.lengh-1); ++i){
		this.indices.push(--i);
		this.indices.push(i);
		this.indices.push(this.vertices.lengh-1);
	}


/*

	this.vertices = [
            0, 0, 0,       //0
            , 0, 0,     //1
            0.5, 0.5, 0,   //2
            0, 0.5, 0,     //3
            0.25,0.25,1.0,  //4

			];

	this.indices = [
            0,1,2,
            2,3,0,
            0,1,4,
            2,4,1,
            3,4,2,
            0,4,3,
            1,0,3,
            3,2,1

			 ];

	*/

	this.primitiveType=this.scene.gl.TRIANGLES;
	this.initGLBuffers()