Getting Started – Step 4

Learn how to use the Minibrix add-on

Apart from MLCad, used to create the models, there is nothing new to learn. The rendering and viewing processes are exactly the same as for Lego modelling. There is just one point to note regarding L3P/L3PAO, for which one of the normally-optional parameters becomes mandatory for converting Minibrix models. This is described lower down.

Using MLCad for Minibrix

Now that you have mastered MLCad in general, you are ready to learn how to use it for Minibrix constructions.

Select the medium (middle) grid setting, which we have redefined to correspond to the size of Minibrix parts.

In the Parts Tree, click the “+” next to “Other Parts”, then click on the letter “X” to show all the parts in the X subtree. All (and only) the Minibrix parts are here.

All the Minibrix parts are fully and correctly pre-coloured. Therefore, as you lay the parts, do not bother setting their colours individually in MLCad. (In fact, changing the colour will have no effect.). Minibrix only has a few valid combinations. This makes it easier to design true models (or prevents cheating, depending on your point of view!)

Take care when placing windows. You might need to zoom in on the view to check that they are the right way round – the black frames to the outside and the clear backing to the inside.


Right – white frame and black grill facing out.


Wrong – white frame and black grill facing in.

Unless you are desperate to prove you could make the building with real Minibrix, you can leave out the hidden features such as Universal Pins, the dovetailed versions of the black and white Half bricks, and internal supporting walls. Virtual Minibrix works very well with “magic gravity”. (So does virtual Lego, come to that.) Minibrix model parts have rather more detail in them than Lego ones, so including the hidden bits can greatly increase the rendering time while making no visible difference to the end result.

The parts available are all the standard parts that were available in the Golden Age of Minibrix, from 1936 to 1959. The common cut-down parts are also included – the split Ridge Tiles, split roofs (half-roof sections) and the bisected windows. Roofs and Tiles are provided to lay on all combinations of slope: Single Angle brick, Double Angle brick and flat.


Roof pitches available. 40° is the slope of an Angle Brick, 20° is the slope of a Double Angle Brick


Laying tiles over Double Angle Bricks cannot be done entirely using the medium grid setting. The geometry doesn't work. It is necessary to lay a complete row, then switch to the fine grid setting and shuffle it to the correct height and lateral position. You might want to zoom the display up to 200% or even 300% to do this accurately.


Tiles laid using medium grid


Tiles after adjusting on fine grid

With real Minibrix it is possible – though expensive – to build intersecting dormer roofs. To do so it is necessary to build the dormer out of Roof Tiles, strengthen the underside with tape, then cut out the slope with a sharp knife. This is effective, but not reversible! An example of the result is shown on the back cover of the Tudor Minibrix handbook, the Handley Castle Grammar School. Now the good news. With Virtual Minibrix, creating intersecting dormer roofs is easy. You simply build the one roof right through the other at right angles. The MLCad, LDView and POV-Ray renderings will all sort out the result perfectly.

A note on performance

If you are constructing a really large building, you may find that MLCad runs unacceptably slowly as it tries to cope with all the fine details. Included in the Virtual Minibrix package is a set of simplified primitives which can be temporarily swapped in to speed things up. The studs and holes are replaced by simple cylinders, and the tiny locating pips and holes for windows and doors are omitted.

When you installed the Minibrix add-on, two new directories were created under /LDraw. They were P-Full and P-Simple. To set up the simplified parts, copy the entire contents of P-Simple into your /LDraw/P directory, to replace some of the files there.

To restore the fully-detailed parts, in particular before rendering a high-quality image, copy the contents of P-Full into your /LDraw/P directory.

L3P and L3PAO

Important note: Always use the -LGEO option with L3P and L3PAO. It will include the special Minibrix colour definitions into the POV-Ray source. If you do not use this option, all your parts will be coloured black in the final image!

Hints and Tips

When you’ve got used to the basics of modelling in Virtual Minibrix, you might like to browse through the small set of “Hints and Tips”, which give some ideas for getting more out of the tools, and for getting round some of the limitations.


Hints and Tips

Page last updated 2 September 2015