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LDraw.org Official Parts Library Standards: General - Printable Version

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LDraw.org Official Parts Library Standards: General - Roland Melkert - 2026-04-22

(Yesterday, 20:27)Orion Pobursky Wrote: It's time to start discussing the LDraw.org Official Parts Library Standards.

Only nitpick I noticed at first read trough:

Quote:Leading zeros unless immediately before the decimal point must be removed (i.e. 1.5, not 01.5).

Found this a bit confusing, so 0.123,  00000.123  and .123 are all allowed?

Maybe:

Quote:Leading zeros unless at most one immediately before the decimal point must be removed (i.e. 1.5, not 01.5).


RE: LDraw.org Official Parts Library Standards: Introduction - Orion Pobursky - 2026-04-22

(Yesterday, 20:46)Roland Melkert Wrote: Found this a bit confusing, so 0.123,  00000.123  and .123 are all allowed?

The first and third are ok, the second is not. This is already enforced by the PT submit validation.

Follow up: Should the PT autocorrect these errors and issue a warning instead?

Good feedback.

RE: LDraw.org Official Parts Library Standards: Introduction - Roland Melkert - 2026-04-22

(Yesterday, 21:09)Orion Pobursky Wrote: Follow up: Should the PT autocorrect these errors and issue a warning instead?

I think this can be an automatic correction (with a proven algorithm).

Maybe followed with a message about what has been corrected?

RE: LDraw.org Official Parts Library Standards: Introduction - Orion Pobursky - 2026-04-22

(Yesterday, 20:46)Roland Melkert Wrote: Only nitpick I noticed at first read trough:


Found this a bit confusing, so 0.123,  00000.123  and .123 are all allowed?

Maybe:

I just realized that this is skipping ahead to the General section. I'll move these posts when I open discussion on that section.

RE: LDraw.org Official Parts Library Standards: Introduction - Gerald Lasser - 2026-04-23

Quote:All part files in the LDraw Parts Library are required to carry the .dat extension.

we do have the texture maps as "png" as well

LDraw.org Official Parts Library Standards: General - Orion Pobursky - 2026-04-23

Since a few people jumped the gun, I'll open the General sections for comments

https://library.ldraw.org/documentation/ldraworg-official-parts-library-standards/general

Some comments from the intro thread have been moved here.

RE: LDraw.org Official Parts Library Standards: Introduction - Travis Cobbs - 2026-04-23

Suggestions for the General page:

Update:
Quote:Files shall not exceed five decimal places
to:
Quote:Numbers in files shall not exceed five decimal places

Update:
Quote:Four decimal places (at a minimum) shall be used for high-res primitives ...
to:
Quote:Four decimal places (at a minimum) shall be used in high-res primitives ...

Regarding this:
Quote:If the geometry is tangent to the curve. If it is sloped further, then a complementary conditional line shall be placed on the edge of that geometry, with the control points past the edge of the geometry configured to be tangent to the curve, and the two end points of the conditional placed to exactly overlap the complementary conditional line on the edge of the curved primitive.

First of all, the first sentence seems to be missing its conclusion (, "then ..."). Secondly, I wanted to verify that these instructions are accurate (along with the sample image). It seems to me that the control point that is on the curve side should be tangent to the curve and not on the next curve vertex. The provided instructions mean that sometimes both overlapping conditionals will be rendered at the same time.

Quote:For hinge or hinge like parts, the origin should be at the rotation point**
The two asterisks at the end are never defined.

Quote:Line types 2 and 5 must use colour 24.
I thought that line type 2 was occasionally allowed to use specific colors in patterns. Is this not the case?

RE: LDraw.org Official Parts Library Standards: General - Chris Böhnke - 2026-04-23

Stud Orientation:
Missing a few words?
"The individual studs on a part should be rotated such that the stud logo appears is [like] it would [be] on the real part."

Duplicate Lines:
Feels a bit random at it's current place in the list. Shouldn't this be more along the basic rules at the top?

Header Meta Commands:
So, older relics like "0 !CMDLINE -c14" are officially gone? Should this be mentioned for older parts?

Colours:
  1. "[...] but does not include the colours of paint used to decorate parts or ink used on stickers."
    It gets a bit confusing when we consider that for example 80-82 (Metallic Silver, Gold, Green) are in fact NOT available as plastic colours, but are required due to their special nature.

    I know this has been there for a long time, but might I take this opportunity to ask why this rule is required? And not allow for example 163 Dark Yellow in LDConfig, where it's confirmed the colour exists and has an official name and number? (Rylie Howerter: https://www.flickr.com/photos/126975831@N07/53456689335/in/dateposted/).

    My main issue with this rule is, that I would rather see these "confirmed" cases (there's also a very common shade of greenish light blue on 1980-1997 patterns, not part of the normal palette) to use a clearly defined colour rather than direct colour. I think it would help in consistency and make certifying these parts a bit easier.

    As a side note, the rules do not specify colours which do exist in plastic form, but never appeared in sets (as far as knowledge goes), like "108 Earth Yellow" (https://www.flickr.com/photos/126975831@N07/32237833395/in/dateposted/)

  2. "In general, metallic colours on stickers, patterned parts, and other printed materials should use the LDraw Metallic Colours and not Chrome or Pearl colours."
    Personally I would prefer the Pearl colours part to be a "must not" instead of "should not", as this should not be possible to be used as ink anyways (chrome is okay in edge cases). Opinions?


RE: LDraw.org Official Parts Library Standards: Introduction - Orion Pobursky - 2026-04-23

(2 hours ago)Travis Cobbs Wrote: First of all, the first sentence seems to be missing its conclusion (, "then ..."). Secondly, I wanted to verify that these instructions are accurate (along with the sample image). It seems to me that the control point that is on the curve side should be tangent to the curve and not on the next curve vertex. The provided instructions mean that sometimes both overlapping conditionals will be rendered at the same time.

The above needs to be discussed.  All the rest of your comments are fixed.

RE: LDraw.org Official Parts Library Standards: General - Orion Pobursky - 2026-04-23

(55 minutes ago)Chris Böhnke Wrote: Colours:
  1. "[...] but does not include the colours of paint used to decorate parts or ink used on stickers."
    It gets a bit confusing when we consider that for example 80-82 (Metallic Silver, Gold, Green) are in fact NOT available as plastic colours, but are required due to their special nature.

    I know this has been there for a long time, but might I take this opportunity to ask why this rule is required? And not allow for example 163 Dark Yellow in LDConfig, where it's confirmed the colour exists and has an official name and number? (Rylie Howerter: https://www.flickr.com/photos/126975831@N07/53456689335/in/dateposted/).

    My main issue with this rule is, that I would rather see these "confirmed" cases (there's also a very common shade of greenish light blue on 1980-1997 patterns, not part of the normal palette) to use a clearly defined colour rather than direct colour. I think it would help in consistency and make certifying these parts a bit easier.

    As a side note, the rules do not specify colours which do exist in plastic form, but never appeared in sets (as far as knowledge goes), like "108 Earth Yellow" (https://www.flickr.com/photos/126975831@N07/32237833395/in/dateposted/)

  2. "In general, metallic colours on stickers, patterned parts, and other printed materials should use the LDraw Metallic Colours and not Chrome or Pearl colours."
    Personally I would prefer the Pearl colours part to be a "must not" instead of "should not", as this should not be possible to be used as ink anyways (chrome is okay in edge cases). Opinions?

Let's discuss the above.

Stud Orientation wording fixed, Duplicate lines section moved, and missing hyperlink added to Header META section.

RE: LDraw.org Official Parts Library Standards: General - Orion Pobursky - 2026-04-23

(Yesterday, 20:46)Roland Melkert Wrote: Found this a bit confusing, so 0.123,  00000.123  and .123 are all allowed?

This is now clarified