Background image not changing

I want to change background image of sky providing custom image but it is not changing

var scene = viewer.scene;
scene.skyBox = new Cesium.SkyBox({
sources : {
positiveX : 'images/galaxy.jpg',
negativeX : 'images/galaxy.jpg',
positiveY : 'images/galaxy.jpg',
negativeY : 'images/galaxy.jpg',
positiveZ : 'images/galaxy.jpg',
negativeZ : 'images/galaxy.jpg',
}
});

In local system i have given these path but in sandcastle demo i have not added image.

Link

Any suggestions, Thanks

@James

Thank you for sharing this issue with the community. Are you receiving an error at runtime? If so, what is the exact error? I looked over the SkyBox documentation and it seems like you are updating scene.skyBox correctly.

https://cesium.com/learn/cesiumjs/ref-doc/SkyBox.html

You could maybe try using a png instead of a jpg, although I am not sure if this will make a difference. I also found this forum thread that might help you get started.

Any suggestions from the rest of the community? I would love to see this issue resolved.

-Sam