How To

Render a Scene to a PNG


How To Render a Scene to a PNG

First you may ask why is it better than "ctrl + prt scr" screenshot?

With a standard ctrl + print screen keypress, you can't create screenshots with higher resolutions than your screen resolution. With BabylonJS screenshot feature, you can. There is no problem with creating a 1920x1080 screenshot on a 800x600 screen (provided the graphics card is powerful enough to compute it). Another cool aspect of using this feature is that you can use a non-active camera to create the screenshot, so you can produce many screenshots, without switching cameras!

It's done by simply calling this method: BABYLON.Tools.CreateScreenshot(engine, camera, size). You need to provide your BabylonJS engine, the camera you want to use for the rendering, and a size. The size parameter is very versatile. Allow me to show you some examples:

  • If you need a square screenshot (ratio 1:1) simply use this: size = 512;.

size = 512 HillValley render

  • If you want to have a custom width and height (like 600x400), use this format: size = { width: 600, height: 400}; If you provide only one parameter within those braces, BabylonJS will compute the missing dimension... and maintain canvas aspect ratio.

600x400 HillValley render

  • If you want to keep your current canvas aspect ratio, yet with more or less precision: size = { precision: 2 } (in this example a 800x600 canvas will give you a 1600x1200 screenshot). Below is an example with precision 0.5 on my computer (the result is 960x503):

HillValley render with precision of 0.5

The result will be automatically downloaded if your browser supports it. Otherwise, it will be displayed on a new tab. In any case, it will be a PNG image format. This feature does not yet support antialiasing.

Just for fun, here is a render of Hill Valley using 3840x2160 resolution (4K).

4K render of Hill Valley