How to enable Desktop Effects
Become root by typing in konsole
su
write the password for root
a)To enable effects just remove the file /etc/X11/xorg.conf.d/disable-composite.conf ( type rm /etc/X11/xorg.conf.d/disable-composite.conf ) and restart X. (Log out of kde-desktop and log in again.)
b) Enable cube and other effects under System Settings > Workspace Appearance.
c) Press ctrl+F11 and using mouse can turn cube. Press ESC key or right clik the mouse to return to desktop.
d) If you want your graphic to appear to up and down side of the cube then copy your graphic image to /usr/share/apps/kwin/cubecap.png (e.g. cp your_image.png /usr/share/apps/kwin/cubecap.png)