3D sketchs by Gael
Adobe Reader needs to be installed on the computer. (Adobe Official site)
Safari works automatically if Acrobat Reader is installed.
In Firefox since version 15, the Adobe Reader pluggin needs to be turned on in preferences/applications/Portable document formats.
Using Chrome browser. Go to Chrome’s address bar and type in: chrome://plugins/
Then disable “Chrome PDF Viewer” and enable “Adobe Acrobat”.