[]matter.jsr Render下可以移动视图窗口 用LayaRender则没反应

我看了一个Matter.js的 移动View示例 
移动窗口代码以下

var carpos = Car.bodies[1].position;
var canvas = render.canvas;
var context = render.context;
var world = {minX: -globalWidth, maxX: globalWidth, minY: -globalHeight, maxY: globalWidth};
context.setTransform(1,0,0,1,0,0);
context.clearRect(0, 0, canvas.width, canvas.height);
//Clamp the camera position to the world bounds while centering the camera around the car
var camX = clamp(-carpos.x + canvas.width/2, world.minX, world.maxX - canvas.width);
var camY = clamp(-carpos.y + canvas.height/2, world.minY, world.maxY - canvas.height);
context.translate( camX, camY );
 
能正常跟随物体移动
 
 
但用LayaRender 后  由于无法获取到
context  所以我改了一下render.canvas.getContext('2d');

var carpos = Car.bodies[1].position;
var canvas = render.canvas;
var context = render.canvas.getContext('2d');
var world = {minX: -globalWidth, maxX: globalWidth, minY: -globalHeight, maxY: globalWidth};
//context.setTransform(1,0,0,1,0,0);
context.clearRect(0, 0,800,600);
var camX = clamp(-carpos.x + canvas.width/2, world.minX, world.maxX - canvas.width);
var camY = clamp(-carpos.y + canvas.height/2, world.minY, world.maxY - canvas.height);
context.translate(camX, camY );
 
发现移动就无效了 也没有什么错误
请问LayaRender是否支持直接移动context？