Friday, November 26, 2010

LDraw Tutorial - Part 4

In the light of some of the questions and problems that have come up after presenting the latest TBs TechChallenge I have decided to prepare some simple instructions for a first time install of the LDraw Parts Library, MLCad and LDview, the basic package you need to participate in this challenge. Rather than using the all-in-one installer provided on

I have just completed this installation on a clean Windows 7 Ultimate, so if you follow these simple steps and the on-screen instructions you will get while installing you should be able to complete installation without any problems. If you still run into any trouble do not hesitate to mention it in a comment and I'll do my best to help you out. If you are using Mac or Linux... I suppose you know what you are doing, but in case there is sufficient interest in some instructions for those OSes I can prepare something later on.

1 - Installing the LDraw Parts Library

First of all you should install the complete collection of parts provided by LDraw. You can find an installation program on this LDraw page. (There is also a zip file with all the parts for those of you who know what they are doing.)

The installer will suggest extracting the files to C:\LDraw and you should probably accept this suggestion. The installer doesn't actually install anything. That is to say, it does not place anything outside the folder it installs to. The only real difference between the zip file and the installer is that in the case of the zip file you have to create the location you want to extract the files to.

There is a good chance you may need parts that have not been officially released yet (for a number of reasons - I will explain something about that at a later time). As you can read in the LDraw Tutorial - Part 2, you can find those parts on the Parts Tracker, but you can also install all of the unofficial files at once by downloading and extracting the full set of Unofficial Parts Files to an appropriate location. To keep things simple use C:\LDraw\Unofficial and make sure the final result is that you get two new subfolders under Unofficial named C:\LDraw\Unofficial\p and C:\LDraw\Unofficial\parts.

2 - Installing MLCad

To install MLCad, go to the MLCad website, select the language of your choice (English or German) and in the navigation bar on the left click on Downloads. Download the latest version V3.30 now (1,1MB). Save the zip file to a convenient location on your computer and then extract it. Where? Well, that's up to you, but in the original LDraw all-in-one installer, applications (programs) were  installed to the Apps folder under LDraw (C:\LDraw\Apps\MLCad in this case for example).

The first time you start MLCad it will ask you where the LDraw Parts Library is (which is why you should install that first). By default it will suggest you to look in C:\LDraw - another good reason to place the parts there.

You are now ready to start working with MLCad. If this is your first time or you need a refresher course, please read the LDraw Tutorial - Part 1.

3 - Installing MLCad.ini

MLCad is not complete without the MLCad.ini file. It's main purpose is to populate the minifig generator with every available minifig part, but there is also a section in MLCad.ini that describes where official and unofficial parts are located.

You can download the latest version of MLCad.ini from the dedicated page on Extract the file in the same folder as MLCad.exe. If you already have a previous version of MLCad.ini, note any manual changes you may have made to it and overwrite it with the most current version.

If you have installed the Unofficial part, now is the time to make a small change in MLCad.ini. Open the file with your favourite text editor (e.g. Notepad) and scroll down to the section that begins with [SCAN_ORDER]. By default it will look like this:

1 = SHOW Parts
2 = HIDE P
; 3 = SHOW Unofficial\Parts
; 4 = HIDE Unofficial\P
; 5 = SHOW Unofficial\LSynth
; 6 = SHOW Unofficial\Helper

As you may have already guessed, you need to delete the semicolon ( ; ) at the beginning of lines 3 and 4 to tell MLCad where the unofficial parts are. Save and close and you are ready to go.

Don't forget to rescan the parts library so MLCad actually sees where the parts are and what parts it has available (open MLCad and go to File > Scan Parts...) This and much more is also described in LDraw Tutorial - Part 2.

4 - Installing LDview

In order to be able to supply a decent quality render of your creation, you will also need to install LDView. You can download the program from its official Download page on SourceForge .

Installation is straight forward, simply follow the instructions and accept default settings. You can ask the program to install to C:\LDraw\Apps\LDview if you would like to keep everything LDraw related in the same place.

You should now have all the necessary tools to participate in the TBs TechREVERSE Challenge!


TechnicBRICKs said...

Very well put, Jetro!

The newbies will be thankful. :)

Anonymous said...

Too bad it didnt work on my 64 bit windows 7... Maybe they could update the program and installer and also make it more noob friendly?

me00rjb said...

I've just built a new PC so had to try and remember how to reinstall MLCAD, etc. Always causes me problems, so this guide has proved most useful. I've downloaded the latest LDraw parts, and the unofficial parts (putting them in the 'unofficial' folder). I've changed the .ini file to scan the unofficial parts and remembered scanned the parts in MLCAD. However, when scrolling through the MLCAD parts list (technic parts for example), I get error messages telling me there are parts (presumably sub-parts) missing. Is there anything that can be done about this? Why are there missing parts in the first place?

yoraish said...

So what about mac?

TechnicBRICKs said...


I think Jetro succeed to install LDraw on Windows 7 Ultimate x64.
So it must be something wrong at your installation. :/


Maybe you have not installed all the Library updates. Remember that LDraw library updates are not cumulative.
Maybe it would be easier if you install the latest Library from a single file, here.


I'm afraid you must wait for an explanation from Jetro.

Daniel said...

Wine can be installed on Mac OS X, but you will need to either use an experimental binary, install some package manager, or install it manually.

Scott said...

Bricksmith is a very good Mac ldraw editor. There's a Mac version of LDView...

Unknown said...

Hi all technic fans!
My first LDraw project (8066) is almost done. I never knew that this software is so capable/strong, because until now I only trusted to LDD.
I have some issues with colors, so please help if someone knows what could be the problem. It is a problem that a lot of colors apear like 'unused'. At SUV both grey colors (71 and 72) are 'unused' and on screen they apear as transparent. When I built it at beginning they were ok, later I added unofficial library and maybe it has to do something with this?
If I can't resolve this problem, can I just put old light-gray and dark-gray instead of the new ones?
Thank you for your answers.

TechnicBRICKs said...


I've not yet been looking in detail to the submission files (will do it in the end of the contest), but one of them includes several unknown parts.
I don't know if they are really missing parts, as everything else seems Ok at first sight, or a problem similar to yours.
However I know it was originated by an LDD-MLCad conversion. So I guess you also have converted your file from LDD!?

The situation you described seems to be specific about colors and not parts themselves. So it may be a different issue.

Which MLCad version are you using 3.20 or the newest 3.30.
One of the 3.30 improvements was the native support for the LEGO colors, like the bluish grays.

But your problems persist, you may use the 'old' grays. For the purpose of this contest, I'll not distinguish between the correspondent 'new' and 'old' grays.

Unknown said...

Tnx Conchas,
At first I had a plan to make it in LDD and later convert it to MLCad. That gave me missing parts and some transparent pieces.
So I decided to make 8066 from zero in MLCad and also there I experienced issues with transparent grays. I am using 3.30 MLCad and it apears that I really have problems with specific colors so I sent file with the old grays.
Great challenge, more of them in the future please! :)

Jetro said...

Sorry to leave you guys waiting...

- I successfully installed on Windows 7 Ultimate x64. If anyone has problems with that, please explain exactly what goes wrong.

- Mac users: instead of using the .exe file to install the LDraw parts Library choose the .zip file and extract in a convenient place.
I don't own a Mac but will look into installation instructions for Bricksmith. There is a MacOS build of LDview on the general Download page for that program.

- I am looking into the colour issue. There is a quick hack (scroll down to "Working with Stone Gray colors") but there should be a better option available now.

Come to think of it, maybe you don't have the latest version of LDconfig.ldr. You can download it here:
and you need to place it under c:\LDraw

Unknown said...

Thank you Jetro, the new grays work ok now.
Maybe this is not the right space, but since I see that you guys are very familiar with MLCad, here is a question. Is it possible to put pictures into the software to have them as a background blueprint/silhuete for building on top of them?

Jetro said...

@Dejan there are several ways to place abackground behind your render, but since you mention having them behind building steps, you may want to use LPub 4

TechnicBRICKs said...

I think Dejan, meant to use blueprint images as background, in MLCad, to help him designing models based on the same blueprint image.

That I don't think to be possible with MLCad.

Jetro said...

Not exactly for MLCad, but for real-life dimention checks etcc, have a look at Sariel's Model Scaler Tool:

Clunbricky said...

Many thanks for posting this. I was struggling a bit until I found this but have now loaded ML-Cad succesfully on my new computer. Thanks again.

TechnicBRICKs said...

This tutorial became listed as a reference, at LDraw home.

Congratulations Jetro!

Jetro said...

Thanks for the heads up Conchas!
How cool is that xD

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