LeoCAD is a CAD application that uses plastic bricks.
The first thing you should do is check that you have an OpenGL library installed in your computer by typing '/sbin/ldconfig -p |grep libGL', you should see libGL.so listed in the output. If you can't find it, then you should download and compile Mesa 3D. Don't forget to add the Mesa installation path to /etc/ld.so.conf or LD_LIBRARY_PATH and run /sbin/ldconfig.
The next step is to download the executable and the pieces library. After the download is complete you have to extract the pieces library to any directory of your choice but if you choose a place other than "/usr/local/share/leocad/", you'll have to set the variable LEOCAD_LIB to that directory.
Now you should extract the LeoCAD precompiled binaries, to any directory and run "leocad".
If you prefer to compile the program yourself, you can use the cvs server :pserver:email@example.com:/usr/cvsroot (password is 'guest') to checkout the module 'leocad'. I recommend using the tag for the last released version, for version 0.73 it's 'leocad-0-73'. You can do this by typing:
$ cvs -z3 -d :pserver:firstname.lastname@example.org:/usr/cvsroot login
Enter "guest" without the quotes when asked for a password to login. Now to download the latest released version, type:
$ cvs -z3 -d :pserver:email@example.com:/usr/cvsroot checkout -r leocad-0-73 leocad
Or if you want the latest development version:
$ cvs -z3 -d :pserver:firstname.lastname@example.org:/usr/cvsroot checkout leocad
Each object in a LeoCAD project can have a different position and orientation for each step or frame that it appears. This feature is called keyframing, and works differently if the program is in Instruction or Animation mode.
This is very useful when creating instructions because it allows you to have a door open in one step and closed later, or have the camera display the model from a different angle on a certain step to show details from another section of the model.
If you're in animation mode, LeoCAD automatically interpolates the value of the previous key with the value of the next key to calculate the position of the object at each frame. This makes the creation of animations a very simple thing because you only need to set the start and end positions and LeoCAD will take care of the other frames.
When the Key Button () from the Animation Toolbar is depressed, a new key is added at the current step/frame each time you move or rotate an object, if a key doesn't already exist. When the icon is not pressed, the changes are made to the key immediately before the current step/frame.
Instructions and Animations
LeoCAD can be used to create building instructions and animations, making it a very powerful editor. When you start the program you're placed in Instruction mode by default, you can switch between Animation and Instruction mode using the Mode Button () from the Animation Toolbar.
Each program mode stores the position and orientation of all objects in separate places, so changing the position of an object on one mode does not change it on the other mode. To easily copy the position from the other mode, choose Copy Keys From ... from the Pieces Menu.
When you're in Instruction Mode, each time unit is called a Step and when you're in Animation Mode, each time unit is called a Frame. The most important difference between the 2 modes is how Keyframing works.