1-16chrd, an interesting idea...

[Chris Dee]

+1

w.

FYI, as far as I know, I no longer have the ability to edit those files. I used to, but there aren't any "edit" links any more (and probably haven't been for years).

The primitives reference is not, and never has been, part of the ldraw.org Content Management System. It is still a bunch of html files with a lot of Server-Side-Includes.
If someone can provide some extra usage text for 1-16chrd, I'm happy to add it.

[Travis Cobbs]

I really don't know how to describe this in a way that makes sense. The following is the best I could come up with.

Note: 1-16chrd.dat is a special case that is used on the inside of a curved primitive where it joins geometry that cannot make use of a curved primitive. The primitive file itself is simply a reference to empty.dat, which under normal circumstances does not draw anything. However, in tools that support primitive substitution, the curved primitive it is attached to would normally in this case create a gap when rendered using more than 16 points to form a circle. In that case, the substituted version of this normally empty primitive would fill in the gap between the curve and the other geometry.

[Chris Dee]

I really don't know how to describe this in a way that makes sense. The following is the best I could come up with.

Note: 1-16chrd.dat is a special case that is used on the inside of a curved primitive where it joins geometry that cannot make use of a curved primitive. The primitive file itself is simply a reference to empty.dat, which under normal circumstances does not draw anything. However, in tools that support primitive substitution, the curved primitive it is attached to would normally in this case create a gap when rendered using more than 16 points to form a circle. In that case, the substituted version of this normally empty primitive would fill in the gap between the curve and the other geometry.

Thanks - primitives reference updated.

[Philippe Hurbain]

I really don't know how to describe this in a way that makes sense. The following is the best I could come up with.

Thanks Travis - difficult to explain indeed, that's why I didn't chime in.

Primref is also missing an entry for related ering primitives (1-4ering, 4-4ering). Something like "Several 1-16chrd placed around a circle, used to fill-in gaps between simple geometry and curved primitives during primitive substitution. See 1-16chrd for more details."

[Willy Tschager]

I really don't know how to describe this in a way that makes sense. The following is the best I could come up with.

Note: 1-16chrd.dat is a special case that is used on the inside of a curved primitive where it joins geometry that cannot make use of a curved primitive. The primitive file itself is simply a reference to empty.dat, which under normal circumstances does not draw anything. However, in tools that support primitive substitution, the curved primitive it is attached to would normally in this case create a gap when rendered using more than 16 points to form a circle. In that case, the substituted version of this normally empty primitive would fill in the gap between the curve and the other geometry.

Thank you Travis! ... Much appreciated.

w.

[Magnus Forsberg]

Chris,
Could we please have this on the primref too?

Primref is also missing an entry for related ering primitives (1-4ering, 4-4ering). Something like "Several 1-16chrd placed around a circle, used to fill-in gaps between simple geometry and curved primitives during primitive substitution. See 1-16chrd for more details."

[Willy Tschager]

The note for "ering" is still missing. You should also explain how to handle "invisible" geometry in an editor: working with "chrd" and after postioning, bfc, ... renaming to "ering". I'm sure you come up with some clever wording.

w.

[Philippe Hurbain]

working with "chrd"

...or ndis. Often chrd comes over existing faces geometry and is not seen much better.

[N. W. Perry]

On a somewhat related note, does the library need a 48/1-48chrd?

Well, I'm working on a part that would call for it, so I went ahead and submitted it, for better or worse:
https://www.ldraw.org/cgi-bin/ptdetail.c...48chrd.dat