BabylonJS - Create ScreenShot

To capture the screen on which you are presently working, it is not possible to take screenshot with high resolution using the print screen keypress. BabylonJS provides createscreenshot APIwhich helps to do so. It saves the file as png format and the quality of the image is not sacrified.

Syntax

To take screenshot of the screen we need to provide engine, camera and the size as shown below.

BABYLON.Tools.CreateScreenshot(engine, camera, { width: 1024, height: 300 }, function (data) {
   var img = document.createElement("img");
   img.src = data;
   document.body.appendChild(img);	
});

A button that calls the screenshot API, when a user clicks it, is put.

Changes are made to the engine which is passed to the screenshot api.

var engine = new BABYLON.Engine(canvas, true, { 
   preserveDrawingBuffer: true, stencil: true 
});

It requires options like preserveDrawingBuffer and stencil set to true.

Button is added as follows −

ssButton = document.createElement("input");
document.body.appendChild (ssButton);

Click event is added to the button above and the createscreenshot is called. It will update the screenshot at the end of the screen. The data used for image src has the screenshot url created.

Demo

<!doctype html>
<html>
   <head>
      <meta charset = "utf-8">
      <title>BabylonJs - Basic Element-Creating Scene</title>
      <script src = "babylon.js"></script>
      <style>
         canvas {width: 100%; height: 100%;}
      </style>
   </head>

   <body>
      <canvas id = "renderCanvas"></canvas>
      <script type = "text/javascript">
         var canvas = document.getElementById("renderCanvas");
         var engine = new BABYLON.Engine(canvas, true, { preserveDrawingBuffer: true, stencil: true });	
         var createScene  = function() {
            var scene = new BABYLON.Scene(engine);
            
            // Setup environment
            var light = new BABYLON.HemisphericLight("light1", new BABYLON.Vector3(1, 0.5, 0), scene);
            
            var camera = new BABYLON.ArcRotateCamera("ArcRotateCamera", 1, 0.8, 20, new BABYLON.Vector3(0, 0, 0), scene);
            camera.attachControl(canvas, true);

            var gmat = new BABYLON.StandardMaterial("mat1", scene);
            gmat.alpha = 1.0;
            
            //gmat.diffuseColor = new BABYLON.Color3(1, 0, 0);
            var texture = new BABYLON.Texture("images/mat.jpg", scene);
            gmat.diffuseTexture = texture;

            var ground = BABYLON.MeshBuilder.CreateGround("ground", {width: 150, height:15}, scene);
            ground.material = gmat;

            var mat = new BABYLON.StandardMaterial("mat1", scene);
            mat.alpha = 1.0;
            mat.diffuseColor = new BABYLON.Color3(1, 0, 0);
            
            var texture = new BABYLON.Texture("images/rugby.jpg", scene);
            mat.diffuseTexture = texture;

            var sphere = BABYLON.MeshBuilder.CreateSphere("sphere", {diameter: 2, diameterX: 3}, scene);
            sphere.position= new BABYLON.Vector3(15,1,0);
            sphere.material = mat;

            var faceColors = new Array();
            faceColors[1] = new BABYLON.Color4(0,1,0,1);   // green front

            var matcone = new BABYLON.StandardMaterial("mat1", scene);
            matcone.alpha = 1.0;
            matcone.diffuseColor = new BABYLON.Color3(0.9, 0, 2);
            
            var texture = new BABYLON.Texture("images/cone.jpg", scene);
            matcone.diffuseTexture = texture;

            var cone = BABYLON.MeshBuilder.CreateCylinder("cone", {diameterTop: 0, tessellation: 4}, scene);
            cone.position= new BABYLON.Vector3(12,1,0);
            cone.material = matcone;

            var matplane = new BABYLON.StandardMaterial("matplane", scene);
            matplane.alpha = 1.0;
            matplane.diffuseColor = new BABYLON.Color3(0.9, 0, 2);
            
            var texture = new BABYLON.Texture("images/board.jpg", scene);
            matplane.diffuseTexture = texture;
            var plane = BABYLON.MeshBuilder.CreatePlane("plane", {width: 5, height : 5}, scene);
            plane.position= new BABYLON.Vector3(9,2.5,0);
            plane.material = matplane;		
            
            var disc = BABYLON.MeshBuilder.CreateDisc("disc", {tessellation: 3}, scene);
            disc.position= new BABYLON.Vector3(5,1,0);		

            var mattorus = new BABYLON.StandardMaterial("matoct", scene);
            mattorus.alpha = 1.0;
            
            var texture = new BABYLON.Texture("images/ring.jpg", scene);
            mattorus.diffuseTexture = texture;
            
            var torus = BABYLON.MeshBuilder.CreateTorus("torus", {thickness: 0.5}, scene);		
            torus.position= new BABYLON.Vector3(3,1,0);
            torus.material = mattorus;

            var matoct = new BABYLON.StandardMaterial("matoct", scene);
            matoct.alpha = 1.0;
            
            var texture = new BABYLON.Texture("images/d1.png", scene);
            matoct.diffuseTexture = texture;
            var octahedron = BABYLON.MeshBuilder.CreatePolyhedron("oct", {type: 1, size: 3}, scene);
            
            octahedron.position= new BABYLON.Vector3(-2,5,0);
            octahedron.material = matoct;	

            var matico = new BABYLON.StandardMaterial("matico", scene);
            matico.alpha = 1.0;
            
            var texture = new BABYLON.Texture("images/diamond.jpg", scene);
            matico.diffuseTexture = texture;		
            
            var icosphere = BABYLON.MeshBuilder.CreateIcoSphere("ico", {radius: 5, radiusY: 3, subdivisions: 2}, scene);
            icosphere.position= new BABYLON.Vector3(-13,3,0);		
            icosphere.material = matico;		
            
            //add screenshot button
            var ssButton = document.getElementById("takescreenshot");
            if (ssButton == null) {
               ssButton = document.createElement("input");
               document.body.appendChild(ssButton);
            }
            
            ssButton.id = "takescreenshot";
            ssButton.type = "button";
            ssButton.style.position = "fixed";
            ssButton.style.right = "0px";
            ssButton.style.top = "100px";
            ssButton.value = "create screenshot";
            
            ssButton.onclick = function () {
               BABYLON.Tools.CreateScreenshot(engine, camera, { width: 1024, height: 300 },
               function (data) {
                  var img = document.createElement("img");
                  img.src = data;
                  document.body.appendChild(img);
               });
            };			
            return scene;
         }
         var scene = createScene();
         engine.runRenderLoop(function() {
            scene.render();
         });	
      </script>
   </body>
</html>

Output

The above line of code generates the following output −

In this demo, we have used images mat.jpg, rugby.jpg, cone.jpg, board.jpg, ring.jpg, d1.png, diamond.jpg. The images are stored in the images/ folder locally and are also pasted below for reference. You can download any image of your choice and use in the demo link.

Images/mat.jpg

Mat Image

Images/rugby.jpg

rugby Image

Images/cone.jpg

Cone Image

Images/board.jpg

Board Image

Images/ring.jpg

Ring Image

Images/d1.png

D1 Image

Images/diamond.jpg

Diamond Image
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