Introduction

This program takes files created by the LDD to POV-Ray and converts them into build animations for rendering in POV-Ray. First things first - this takes a long time to run (it could be weeks). It only works on Windows and will require the following:

• Lego Digital Designer
• An LXF file from LDD containing the model you want to render
• the LDD to POV-Ray Converter (remember to reboot after installing this)
• POV-Ray
• This program (download here: lego-animate.exe)
• (Optional) BluePrint (it's a program for generating instructions from LXFs, and can optionally be used to generate the build order for the animation)
• Some way of turning many picture files into a video (I used VirtualDub)

If you are an impatient sort, you can jump straight to the Running It section. But, I warn you, you're going to have things go wrong that I'm about to describe in earlier sections and after a week or two of your computer rendering the thing you're going to discover it doesn't look right.

Build Order

There are two ways to pick the build order. Probably the best one (and my original idea) is to generate some instructions with BluePrint, and draw the pieces in the order suggested by BluePrint. However, while messing around with this I discovered that LDD actually orders the parts as you draw them in the designer. So we can just steal that order. It's not perfect - if you delete a piece and add another one, the new one gets plopped in the order position of the original, so it can go out of sync easily.

In the examples below I'm not using a MOC of mine - these are renders of the very nice Joe's Cantina by Berth.

Here's an example of a build order built in BluePrint:

And here's the same model with the original LDD build order:

You can see that there are some artifacts in the wrong place when using the LDD order - as these were the first pieces placed, it was easy to track them down and just correct the order.

Here's that model with some pieces manually fudged to be later in the order:

As you can see, using the LDD order is a bit more attractive but won't work well for models that have been tweaked a lot in LDD.

Running It

The sequence of events is broadly:

1. Generate POV and INI files using LDD to POV-Ray
2. Run those through lego-animate to generate the *-anim.ini and *-anim.pov files
3. Render those in POV-Ray
4. Turn the PNGs POV-Ray created into a video

Suggested Step-by-Step

In real life, running this takes a few tries to get things right, and rendering takes a long time. So this is my recommend sequence of steps:

1. Install everything listed in the Introduction
2. Run Windows Update on your computer. Because it's going to be on for a long time, and you don't want it forcing a reboot. Ask me how I know
3. Open your LXF file in LDD and put it in the middle of the screen (moving the model doesn't mark the file as needing saved so you may have to add a brick and remove it)
4. Save the model and close LDD
5. Load the LDD to POV-Ray converter and create a POV file from it. I'd recommend setting the level of detail on the "Model" screen to the second setting ("original LDD geometry + visible bevels") because rendering the "Lego" logos on all the bricks is very time consuming
6. Do not close the LDD to POV-Ray converter. It has generated binary files that POV-Ray will need and needs to be kept running
7. Prepare a very low-resolution, low-quality 200x100 animation in 50 frames by running lego-animate -i myfile.pov -q1 -w200 -h100 -f50
8. Open POV-Ray and load myfile-anim.ini. Hit "Run"
   1. Make a pot of tea
9. Flip through the various resulting PNG files. The renders will look horrible but don't worry - does the build order look decent?
10. If it doesn't:
    1. Run BluePrint
    2. Import your LXF file
    3. Save the resulting instructions
    4. Prepare a very low-resolution, low-quality 200x100 animation in 50 frames by running lego-animate -i myfile.pov -q1 -w200 -h100 -f50 -b instructions.blueprint
    5. Render myfile-anim.ini in POV-Ray
    6. Does the build order look decent? If so, keep adding the blueprint file on the command line. If not, remove it (you may want to look at Manually Editing Build Order)
11. If you do not want to rotate the model during animation, generate a lovely high-quality 100-frame render by running lego-animate -i myfile.pov -q1 -a true -w800 -h600 -f100 -b instructions.blueprint
    1. Make an entire jug of tea
12. If you do want to rotate the model, generate a low-quality animation by running lego-animate -i myfile.pov -q1 -w200 -h100 -f50 -b instructions.blueprint -r720 -e540. This will rotate the model by 720 degrees during the build, and finish the actual building at 540 degrees
13. Render this in POV-Ray. If the model twirls in an odd way on its axis, move it around a bit in LDD and go back to step ???
14. If this looks good, generate a high quality 250 frame render by using something like lego-animate -i myfile.pov -q1 -w800 -h600 -f250 -r720 -a true -e540 -b instructions.blueprint
15. Render this in POV-Ray
    1. Make tea for your entire neighbourhood and distribute it
16. Once you're happy with the PNG files, combine them into a video. To do this using VirtualDub:
    1. Download and install the XVID video codec, which seems to work best
    2. Open VirtualDub
    3. Select File..Open Video File and choose the first frame of your render
    4. Select Video..Frame Rate and select a frame rate that will work (10fps isn't too bad - 25fps looks lovely but bear in mind your 250 frame video will last 10 seconds)
    5. Select Video..Compression and select Xvid MPEG-4 Codec
    6. Hit File..Save as AVI
    7. If you're having trouble getting the output videos to run on things, you may want to convert them to MP4. The easiest way I found to do this was this handy online converter
17. Impress your friends
18. To make a truly gorgeous 4k 1000-frame version of your render, try lego-animate -i myfile.pov -q1 -w3840 -h2160 -f1000 -r720 -a true -e540
    1. Buy a tea plantation and start growing tea plants on it

Command Line Options

The following options are available (just run lego-animate without any parameters to see this list):

  -i, --input         Required. Input POV file.

  -b, --blueprint     Input BluePrint instruction file.

  -w, --width         (Default: 320) Width of output images.

  -h, --height        (Default: 200) Height of output images.

  -f, --frames        (Default: 50) Number of frames to render.

  -r, --rotate        (Default: 0) Number of degrees to rotate model during
                      animation.

  -e, --endbuildat    (Default: 0) Degrees of rotation at which to finish
                      building.

  -q, --quality       (Default: 9) POV-Ray quality setting to render at (1-9).

  -a, --antialias     (Default: False) Whether to antialias resulting images.

  --help              Display this help screen.

Manually Editing Build Order

Do not edit the build order inside the BluePrint app! It will not be respected (I rely on some rather ephemeral item IDs happening to be the same, and if you change the build order BluePrint changes them all).

This only applies where you're not using BluePrint to generate the build order. If you look inside the .pov file created by LDD to POV-Ray, you'll see a line reading #declare ldd_model = union { and then all of the elements in their build order. You can just move them around (and then rerun this program) to modify that order. Each element is named ldd_something where something is the ID of the brick being used. The easiest way to find out which is which is to load up LDD and search for that brick ID. I never said this was going to be easy. Remember not to run LDD to POV-Ray again though, as it will zap your carefully crafted changes.

Hints and Tips

• If you're intending using the computer for other things at the same time as the rendering, in POV-Ray select Render..Render Priority and set it to Background. As otherwise the mouse stops moving every so often and it's rather annoying. It will still use 100% of CPU when it can.
• Bear in mind that each frame is likely going to be slower to render than the previous one, as there are more parts in it.
• If you opted to rotate the model, it might rotate around a rather strange axis. Open the original .pov file created by LDD to POV-Ray and look for the line #declare ldd_model_transformation = transform { translate <0,0,0> }. Those numbers are distances to move the model on the X, Y and Z axes. Try adjusting the first two of them (I'd suggest by numbers less than 10) to see where the thing ends up, and rerun the animation. I need to find a better way to do this, but haven't yet.
• Transparent parts (windows, the little 1x1 coloured transparent pieces, etc) will increase your rendering time horribly. Horribly. I mean, adding one light to your car might make it take ten times as long to render. This is due to the light behaving in complicated ways through these, and there's not a lot you can do about it.
• The "ground plane" under the model seems to follow it - this means that extending the model downwards during a build will make for some moving shadows. You'll see what I mean when I see it.

Things That Might Go Wrong

• If POV-Ray falls over on some sort of #include, it's probably because you're not runing LDD to POV-Ray, or you haven't generated this exact model with it beforehand.