Some people never let go of their toys. Others adapt them to their adult lives, which is what Tim Courtney has achieved as steering committee chairman of LDraw.org. LDraw is free CAD program for building and sharing virtual LEGO block creations. It allows you to create building instructions, 3D photo-realistic images, and even animations of your LEGO models or scenes. We asked Tim some questions about his high-tech hobby before his appearance on The Screen Savers.

What is virtual LEGO?

Say you build a LEGO model out of your physical bricks, like you normally would. Using some free virtual LEGO software you can download on the Internet, you can create a digital record of your model. By doing this, you can always recall how you put a model together. You can also share the model with others who have the software, so they can build your creation, too.

LDraw is a system, a library of parts and a file format for describing LEGO models in 3D. The system was designed by James Jessiman, who passed away in 1997. An online community of developers has continued development of the LDraw system and written various tools which have made it easier to create virtual LEGO models. As far as physical models out of virtual models -- that's the whole point. Virtual models for many are a means to an end, which is sharing physical construction ideas.

You actually wrote a book on this, didn't you?

Yes. The book is called Virtual LEGO, and I co-wrote it with Steve Bliss and Ahui Herrera. It walks you through the entire process of creating your own virtual models, and teaches you the basic steps to creating some of the really cool stuff I brought like the instructions and the posters.

How do you make the instructions?

The entire process is a bit lengthy to explain, but I'll try to give you the short version.

• The first step for creating a model is dragging pieces onto the screen using an editor program.
• Next, you insert steps and special commands into the file you're working on.
• Finally, you can use another program called LPub that automatically renders every image you need for instructions.
• LPub can create a basic page layout, or you can do what I did and lay the step images out yourself.

Can anyone make instructions? How hard is it?

Anyone can make instructions for simple models. Creating instructions for more complicated models requires a bit of skill. I teach advanced building instruction techniques in Chapter 12 of Virtual LEGO, and also provide sample source files on the CD-ROM for reference.

What are some other cool things you can do with this?

I brought some posters of renderings and scenes people have created. To make these, you export LDraw files to POV-Ray and render them with some photo-realistic settings. Jeroen de Haan has a web site (www.digitalbricks.nl) with a lot of artwork like this.
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The LDraw web site holds a monthly scene competition. I also display posters like these in galleries at LEGO events and at SIGGRAPH annually.

The other thing I brought to show is a cool animation. It was created in POV-Ray. It didn't use LDraw parts; instead, the models are made from a guy named Anton Raves' POV library of LEGO parts. Anton and James Reynolds worked pretty hard to get this ready for you to see today.

This looks like complicated stuff -- what does the average person use this for?

Many people use LDraw to document their own creations and share them with each other. Say you have a model you built, and you want to keep it together. But you have a limited collection to build with. LDraw it (we use the word as a verb, too), save the 3D model to your hard drive, and you'll always remember how to put your model back together again.

How many people use this software?

We don't have exact figures. I know we've had over 100,000 downloads of the core libraries since the site launched in 1999. Who knows how many people actively use this stuff now, but based on our stats it's at least in the tens of thousands.

Who maintains this?

We have a volunteer organization that maintains the web site and sets standards. The software is written by the developer community.

Related Sites:

Get the LDraw software: www.ldraw.org

Enter the non-profit software developer contest to develop the next generation of LEGO CAD software: www.LPRIZE.com

Check out cool 3D LEGO LDraw creations: www.antonraves.com