Before you can model anything you need to install LDCad and its LDraw dependencies. There are multiple ways of doing this so below are some simple steps to follow.
LDraw.org “All In One Installer”
If you are on Windows and want to get going with a whole bunch of LDraw tools in a single step, you might consider using the “AIOI” program instead of doing the below manual LDraw and LDCad installations.
If you do so be sure to check LDCad in the list of programs to install.
Do note the AIOI package might contain an older version of LDCad, if so you can always run a normal LDCad windows setup as found in the downloads section afterward as it will upgrade the version installed by AIOI, given you used its default installation folders.
Afterward you can skip this whole chapter and proceed to the next one if needed.
Installing the LDraw library
The LDCad default package does not come with any kind of library as libraries are shared among all tools supporting it. So before you install LDCad it self you first need to download and install the latest official LDraw library.
After opening the above link download the “complete.zip” file. Once this zip file is on your computer move it from your browser's download folder to some logical (new sub) folder. e.g. “Documents/LDraw” on Windows, or “~/LDraw” on Linux.
Once moved you can leave it as is when you are not planning to use any other LDraw tools besides LDCad on your computer. If you do plan to use other software (e.g. LDView or LPub3D) you need to unpack the library contained inside the complete.zip file using your archive software's “unpack here” option. This will give you another “ldraw” subfolder which you can leave as is or rename to something like “library”.
The compressed state is preferred as the zip holds thousands of relatively small files which can be very wasteful disk space wise. If you must unpack the library it might be an option to use your file system's “compress this folder” option if available.
After installing the LDraw library, or if you already have one installed, you are ready to install LDCad itself.
Grab the top most version for your platform from the downloads section. For Windows there are two options: a setup and an archive, you'll only need one. After doing so skip to the below section of your choice.
Windows Setup version
The easiest to install on Windows is the setup one, this is a normal Windows installer program like you probably used tons of times. Once downloaded execute it and follow its instructions.
When it is done doing its thing you can delete the downloaded file and skip to the “First run” section below.
Windows archive version
The Windows archive version is mend for people who want to try the program without having to 'pollute' their system. It can also be used in situations where the program needs to be portable (e.g. run from a network or USB drive (not recommended though).
The archive contains the exact same files the setup does but can be manually unpacked anywhere. Just be sure the intended folder has read/write access for the current user at all times (e.g. your “Documents” folder).
Once unpacked you simply run it by executing ether the LDCad32.exe or LDCad64.exe program file. The 64bit version is preferred as modern PC's usually run a 64 bit Windows version. The setup would have made this choice automatically based upon your Windows version.
Except for the location of configuration files (all kept inside the exe file's own folder) LDCad will behave the same compared to a setup installed version. You can therefore skip to the “First run” section below.
Linux archive version
Linux currently only has an archive version containing the binaries and core support files. These are compiled on a Debian system so any derivative distribution (e.g. Ubuntu, Suse, Mint, etc) should have no problem running the program as long GTK2 is also installed (most distributions do so by default).
If you need a version for some distribution not able to run the default binaries, feel free to mail me with directions to a LIVE ISO I can use in a virtual machine and I'll see if I can compile a version on that platform for you.
Unpack the tar.bz2 somewhere suitable, e.g. into your home folder. Just be sure the current user has full read/write access to this folder.
Once unpacked you'll notice a LDCad32 and a LDCad64 binary which one to use depends on the version of your OS (usually 64 bit on modern PC's).
If you just want to try LDCad, you can skip to the “First run” section below. But if you want to integrate the program with your desktop environment you'll need to do one additional thing.
Besides the two executable files you'll also find a setup.sh bash script. This script will try to embed LDCad into your desktop like many other Linux programs do (by separating binary, shared and local data).
You'll need to run this script at (sudo, preferably from a terminal) root level as it needs to copy things into “/etc”, “/usr/bin” and “/usr/share”. Feel free to inspect the script before executing it.
Once the script has been executed successfully LDCad should appear in the graphics menu and double clicking any “.ldr” or “.mpd” file should open it loading the clicked file.
If all went well you can delete the downloaded and unpacked files as copies have been made and continue to the “First run” section below.
After installation LDCad is ready to be used, just start it from the menu or double click its main executable in case of a raw archive version.
When first started a very short license agreement will be shown. This, in essence, just asks you to agree to only use LDCad for non commercial / personal / educational use.
After agreeing a folder browse dialog will appear asking for the LDraw library location. Use this to navigate to the location of “complete.zip” or its unpacked root folder (the one holding the “parts” and “p” sub folders).
After you do this the main program window should appear containing an “Updating content please wait” message inside the left sub window. This indicates a library change was detected and some caching / analyzing needs to be done upon it before it can be used in the part bin.
The needed work shouldn't take too long on a modern PC (couple of seconds). Although the work is done in the background (you can actually already open a LDraw file if you want) it is best to wait for the program to finish, indicated by the message being replaced by a grid of icons.
That is it, LDCad is ready for normal use. Feel free to feel your way around for a bit by loading existing LDraw models. Or lean to work with LDCad in its intended way by reading the rest of the documentation starting with the GUI introduction page.