无法在three.js r94中添加SpriteCanvasMaterial

Question

const particleMaterial = new THREE.SpriteCanvasMaterial({
    color: 0x000000,
    program: function(context) {
        context.beginPath();
        context.font = 'bold 20px Arial';
        context.fillStyle = '#058';
        context.transform(-1, 0, 0, 1, 0, 0);
        context.rotate(Math.PI);
        context.fillText(wordFont, 0, 0);
    }
});
const particale = new THREE.Sprite(particleMaterial);
this.scene.add(particale);

上面的代码导致错误。

我只想在three.js场景中添加一些画布形状。