I hope this is in the "right" section; if not, mods, give the noob a thousand e-lashes.

I'm working on a 3D app right now, and have had way too much "fun" in working with the Ldraw file format. I would not call my work anywhere close to compliant with the Ldraw spec, but suffice to say, I've made some progress...and along the way, rediscovered linear algebra, projections, angles, and more.

Here's a pic of what I've got working so far.


Now, for my questions:

-How do you approach non-certified BFC files? Do you check for bowtied parts? Do you treat it as uncertified even if it only contains subparts/primitives? Unfortunately, due to resource limitations, I cannot simply duplicate every noncertified polygon I come across, so I've had to learn to process said polygons as if they are two-sided (which has NOT been fun). I cannot recall, but somewhere between 2997/2998 and 6581/6582, I encountered flipped polygons, bowtied polygons, and more...enough that I have a headache from all that checking.

-Do you have any recommendations on how to perfect normal smoothing? If I find two triangles meet at an angle 180 += 30, I consider them to be part of a curve and I smooth them proportionally to the triangle corner angles. I seem to get a little too much smoothing out of that, but I need to be able to catch at least 180+=22.5 to smooth the stubs (plus using the 48 versions isn't an option).

-How accurate are the ldraw parts? This may be a very bold statement to make, but I do plan to perform intelligent part snapping based solely on the polygons I extract from a ldr file.

-Legally: Can "The Lego Group" prevent me from selling an app I make (provided that I do not use their trademark)? If I want to use the ldraw parts library, what's the recommended way to share it? It seems that, aside from parts/756.dat parts/s/2336s35.dat, I could distribute the zip myself. (Edit: nevermind per #2. I see there's a link for CCAL-compliant parts).

-is there anything you wish you had known when you started working on your program?

Thanks in advance

The following thread says that the current documentation for the 0 Name: line in the LDraw spec is incorrect:

http://forums.ldraw.org/showthread.php?t...56#pid7256

While I personally feel that the current documentation is more ambiguous than outright wrong (there's some ambiguity in the term "filename"), I agree that it would be better for the spec to be clear and unambiguous.

This is my first post. I hope I follow all guidelines.

I want to know the dimensions of a cheese slope tile. I have downloaded the 54200.dat parts file, but I'm not sure how to interpret it. Can anybody help me?

I am interested in knowing the exact length of the side with a length of approximately 8.5mm:
http://www.flickr.com/photos/ltdemartinet/4293993602

Thank you,
Tommy

Here are the contents of 54200.dat:
0 Slope Brick 31 1 x 1 x 2/3
0 Name: 54200.dat
0 Author: Orion Pobursky [OrionP]
0 !LDRAW_ORG Part UPDATE 2009-02
0 !LICENSE Redistributable under CCAL version 2.0 : see CAreadme.txt

0 BFC CERTIFY CCW

0 !HISTORY 2006-01-14 [cwdee] Rotated to match other slope bricks
0 !HISTORY 2009-09-03 [PTadmin] Official Update 2009-02

2 24 10 -16 10 10 -1 10
2 24 -10 -16 10 -10 -1 10
2 24 -10 -4 -10 -10 -1 -10
2 24 10 -4 -10 10 -1 -10
2 24 10 -1 10 -10 -1 10
2 24 10 -1 -10 -10 -1 -10
2 24 10 -16 10 -10 -16 10
2 24 10 -4 -10 -10 -4 -10
2 24 10 -1 10 10 -1 -10
2 24 -10 -1 10 -10 -1 -10
2 24 -10 -16 10 -10 -4 -10
2 24 10 -16 10 10 -4 -10
4 16 -10 -16 10 -10 -1 10 -10 -1 -10 -10 -4 -10
4 16 10 -16 10 10 -4 -10 10 -1 -10 10 -1 10
4 16 10 -16 10 10 -1 10 -10 -1 10 -10 -16 10
4 16 6 -10.6 6 -6 -10.6 6 -6 0 6 6 0 6
4 16 6 -3.4 -6 6 0 -6 -6 0 -6 -6 -3.4 -6
4 16 10 -4 -10 -10 -4 -10 -10 -1 -10 10 -1 -10
4 16 -10 -16 10 -10 -4 -10 10 -4 -10 10 -16 10
2 24 9 0 9 -9 0 9
2 24 9 0 -9 -9 0 -9
1 16 0 -1 0 0 0 9 0 1 0 -9 0 0 box4.dat
4 16 10 -1 -10 9 -1 -9 9 -1 9 10 -1 10
4 16 -10 -1 10 -9 -1 9 -9 -1 -9 -10 -1 -10
4 16 10 -1 10 9 -1 9 -9 -1 9 -10 -1 10
4 16 -10 -1 -10 -9 -1 -9 9 -1 -9 10 -1 -10
4 16 6 0 -6 6 0 6 9 0 9 9 0 -9
4 16 -6 0 6 -6 0 -6 -9 0 -9 -9 0 9
4 16 -6 0 -6 6 0 -6 9 0 -9 -9 0 -9
4 16 6 0 6 -6 0 6 -9 0 9 9 0 9
4 16 6 -10.6 6 6 0 6 6 0 -6 6 -3.4 -6
4 16 -6 -10.6 6 -6 -3.4 -6 -6 0 -6 -6 0 6
2 24 6 0 6 -6 0 6
2 24 6 0 -6 -6 0 -6
2 24 6 0 -6 6 0 6
2 24 -6 0 -6 -6 0 6
2 24 6 -10.6 6 -6 -10.6 6
2 24 6 -3.4 -6 -6 -3.4 -6
2 24 6 -3.4 -6 6 -10.6 6
2 24 -6 -3.4 -6 -6 -10.6 6
2 24 -6 -10.6 6 -6 0 6
2 24 6 -10.6 6 6 0 6
2 24 6 -3.4 -6 6 0 -6
2 24 -6 -3.4 -6 -6 0 -6
4 16 -6 -10.6 6 6 -10.6 6 6 -4 -5 -6 -4 -5
3 16 -3.1092 -4 -5 -2.2961 -4 -5.5434 -2.2961 -3.674 -5.5434
5 24 -2.2961 -4 -5.5434 -2.2961 -3.674 -5.5434 -3.1092 -4 -5 -2.2961 -4 -5.5434
4 16 -2.2961 -4 -5.5434 0 -4 -6 0 -3.4 -6 -2.2961 -3.674 -5.5434
5 24 0 -4 -6 0 -3.4 -6 -2.2961 -4 -5.5434 2.2961 -4 -5.5434
4 16 0 -4 -6 2.2961 -4 -5.5434 2.2961 -3.674 -5.5434 0 -3.4 -6
5 24 2.2961 -4 -5.5434 2.2961 -3.674 -5.5434 3.1092 -4 -5 2.2961 -4 -5.5434
3 16 3.1092 -4 -5 2.2961 -3.674 -5.5434 2.2961 -4 -5.5434
2 24 -3.1092 -4 -5 -2.2961 -4 -5.5434
2 24 -2.2961 -4 -5.5434 0 -4 -6
2 24 2.2961 -4 -5.5434 0 -4 -6
2 24 3.1092 -4 -5 2.2961 -4 -5.5434
2 24 -3.1092 -4 -5 -2.2961 -3.674 -5.5434
2 24 -2.2961 -3.674 -5.5434 0 -3.4 -6
2 24 2.2961 -3.674 -5.5434 0 -3.4 -6
2 24 3.1092 -4 -5 2.2961 -3.674 -5.5434
2 24 -3.1092 -4 -5 3.1092 -4 -5
4 16 -3.1092 -4 -5 0 -4 -5 0 -4 -6 -2.2961 -4 -5.5434
4 16 3.1092 -4 -5 2.2961 -4 -5.5434 0 -4 -6 0 -4 -5
4 16 -3.1092 -4 -5 -2.2961 -3.674 -5.5434 -6 -3.4 -6 -6 -4 -5
3 16 -6 -3.4 -6 -2.2961 -3.674 -5.5434 0 -3.4 -6
4 16 3.1092 -4 -5 6 -4 -5 6 -3.4 -6 2.2961 -3.674 -5.5434
3 16 6 -3.4 -6 0 -3.4 -6 2.2961 -3.674 -5.5434
0

I believe this part is not available, neither are its separate components: http://www.peeron.com/inv/parts/2740c01
Is anyone willing and able to model it?

It took me about ten years to realize that the 0 Name: entry is not used by any application. It is only there to identify the part and the licenses that it is under!

By reading the specs carefully for the 0 Name: entry I found in the Official Library Header Specification only the description that the 0 Name: entry is followed by the filename!
I doubt that 's\file.dat' or '48\file.dat' is a filename. It is a filename with relative path information.

For the '48' I can imagine that this is neccessary to address, as there might be a file with the same name in the 'p' folder. To know which of the files the current context is, it makes sense to add that ('48') information to the filename.

For the 's' the above mentioned is not correct, as subfiles needs to carry a 's' in the filename. So there cannot be any double file name. So my guess is that this is only added because we cannot avoid the '48' entry and by doing it this way all subdirectories of parts and p are addressed the same way.

But the above are mainly my thoughts (nothing is written about that) and so one main question still exists for me:
1) Why do we add the prefix to the filename? No application uses that line as it is not recommended in the File Format 1.0.2
2) Why does the Official Library Header Specification did not mention the use of the path prefix for 's' and '48'?

Michael Heidemann has requested that we add official clarification of how tools should deal with the MPD language extension.

See here:
http://forums.ldraw.org/showthread.php?t...37#pid7237

Given the importance of the MPD meta command, I think it would be good if, somewhere in the official specs, we stressed that support for the MPD meta command is highly recommended, and also note that the MPD meta command can be used in LDraw files with any file extension, not just in files with ".mpd" as the file extension.

Thoughts?

BrickPad 2.1.1 is available...

- 100% GLKit.
- Updated to modern Objective-C syntax.
- Animate standard orientation changes.
- Support for ROTSTEP meta command.
- Fixed a bug where setting changes were propagated to the rendering of the in-step parts list rendering.
- Fixed a bug where the model browser wouldn't reload.

20011 - Garbage Truck

Attached Files

  20011 - Garbage Truck.ldr (Size: 4.49 KB / Downloads: 8)

I'd like to request the following parts:

- 3039px41 --> Slope Brick 45 2 x 2 with Radar and Floppy Disk Slot Black Pattern
- 3039px57 --> Slope Brick 45 2 x 2 with Attitude Indicator and Flight Controls Pattern
- 3068bpx104 --> Tile 2 x 2 with Windows in Computer Screen Pattern
- 54090 --> Cockpit 8 x 16 x 2 Curved
- 54092cx1 --> Windscreen 8 x 16 with Smoke Glass and Blue Airline Bird Logo Pattern
- 54701cx1 --> Plane Fuselage Tail 12 x 16 x 7 with MdStone Bottom and Blue Stripes Pattern

Thank you in advance.

I'm still working on the flexible part support in the next LDCad version, the system is setup in such away you can use pretty much any existing LDraw file as a donor (e.g. pneumatic segment etc).

But there are many flexible parts that don't have suitable donor parts in the existing official library. To supply non expert users with an easy to use 'out of the box' flexible part library I will need to create a collection of additional donor files.

So I was hoping if there's someone interested in helping me create these files. Some are easy like the 'technic axle flexible' those are pretty much just subsections of e.g. 32199.dat (caps and two different segments).

Others need some more thought like suitable segments for 'hose flexible', the existing ones in the official library are only useable for 'reference' placement like LSynth does.

I'm also thinking about supporting very weird things like bendable technic bricks (a real 16x1 brick can easily be bend 1 or 2mm), supporting this would only require a 'technic brick segment'.

There are more needed donors I'm sure, I haven't made an exact list yet. Such a list will come together on it's own when I start creating templates for all bendable stuff. If someone has such a (bendable parts) list (or want to compile one) that would be very helpful too.

So if anyone is interested please respond here or email me directly (address is on melkert.net/ldcad )