问文本不会出现在Babylon.js顶部

EN

window.addEventListener('DOMContentLoaded', function(){
            var canvas = document.getElementById('renderCanvas');
            var engine = new BABYLON.Engine(canvas, true);
            var createScene = function(){
                var scene = new BABYLON.Scene(engine);
                var camera = new BABYLON.UniversalCamera('camera1', new BABYLON.Vector3(0, 5,-10), scene);
                camera.setTarget(BABYLON.Vector3.Zero());
                camera.attachControl(canvas, true);


                var light = new BABYLON.HemisphericLight('light1', new BABYLON.Vector3(0,1,0), scene);


                var sphere = BABYLON.Mesh.CreateSphere('sphere1', 16, 2, scene);
                sphere.position.y = 1;


                var ground = BABYLON.Mesh.CreateGround('ground1', 100, 100, 100, scene);


                scene.gravity = new BABYLON.Vector3(0, -9.81, 0);


                camera.ellipsoid = new BABYLON.Vector3(1, 1, 1);
                scene.collisionsEnabled = true;
                camera.checkCollisions = true;
                ground.checkCollisions = true;
                sphere.checkCollisions = true;
                camera.applyGravity = true;


            }
            var scene = createScene();


            engine.runRenderLoop(function(){
                scene.render();
            });


            window.addEventListener('resize', function(){
                engine.resize();
            });
        });

        var canvas = document.getElementById("myCanvas");
var ctx = canvas.getContext("2d");
ctx.font = "67px Arial";
ctx.fillText("TEST", 10, 50);