Problem when building

May I ask why it shows build.xml does not exist when I build.

Check if you have a build.xml file in the root directory where you have the cesium source-code.

If you dont have it.

Try to download the complete source-code once again.

If you have it.

You probably are running the command wrong.

try running " ./Tools/apache-ant-1.8.2/bin/ant combine runServer " without the quotes from the root cesium directory itself.

Hope it helps!