To LUGNET HomepageTo LUGNET News HomepageTo LUGNET Guide Homepage
 Help on Searching
 
Post new message to lugnet.cadOpen lugnet.cad in your NNTP NewsreaderTo LUGNET News Traffic PageSign In (Members)
 CAD / 16628
     
   
Subject: 
Re: Assembled parts, ~ and categories
Newsgroups: 
lugnet.cad
Date: 
Wed, 18 Nov 2009 14:16:51 GMT
Viewed: 
9922 times
  

In lugnet.cad, Michael Heidemann wrote:
In lugnet.cad, Philippe Hurbain wrote:
It is common practice to prefix parts that compose assembled parts with a ~.
This prevent using them needlessly (they are not listed with regular parts),
encouraging the use of assembled shortcuts.

But this practice is not ratified by any official LDraw document. As a LDraw
Standards Committee member, I'd like to precise this usage. This is a request
for comments...


There is one document that introduced this.
http://www.ldraw.org/library/tracker/ref/filetypesfaq/

I found we have different problems to solve:
1) Usage of the tilde '~' for files in the \s folder.
2) Usage of the tilde '~' for files in the \parts folder
3) Is the tilde '~' part of the description or only a flag.

I think as follow:
1) As nearly all files in the \s folder do have a leading '~' we should force
that for files in the s\ folder.

2a) I don't feel that we should make things that complicated.
If we have a shortcut for the complete part (as we have today). It is no problem
to figure out which parts to bring into a new file to get what we want.
The other way would blow up the library.
Just if you are working with MLCad it is not a problem to generate what you
need.

2b) To work with LSynth is really make sense to have the ends visible to find
that. Although also here a global shortcut will have all the user needs. And
again it is easy to identify what you need with MLCad.
But we should be consistent in using or not using the '~' for such parts.

3) As the '~' is used as a flag we should also handle it as that, so if there is
a partfile in the \parts folder that carry the '~' in front of the
partdescription the partdescription is assumed to be without the '~' and so the
first word has to be in the category list or a category has to be mentioned (See
requirement: http://www.ldraw.org/Article398.html).
This has also to be decided for the "_" flag for colored parts!

cu
mikeheide

Hi,
I read the above article and is OK, but many parts do not follow these
requirements:
for example part 71427C01.DAT distributed as official is named as assembly but
contains the whole part definition inside with no references to any subparts but
parts\P parts.

In my personal opinion, from a programmer point of view, it could be a good
practice to correctly code as assembly at least those parts that allow
reciprocal movement in between them.
For example a switch has a lever that moves while the base is static; a motor
has an axle that rotate while the rest of the model is static.

Other assembly should be multicolored parts (with the exclusion of patterned
parts), since sometime these color can change.

One more question: what does the suffixes "Dxx" and "Txx" stand for?

regards...

Sergio

   
         
     
Subject: 
Re: Assembled parts, ~ and categories
Newsgroups: 
lugnet.cad
Date: 
Wed, 18 Nov 2009 17:46:28 GMT
Viewed: 
9776 times
  

In lugnet.cad, Sergio Reano wrote:
In lugnet.cad, Michael Heidemann wrote:
In lugnet.cad, Philippe Hurbain wrote:
It is common practice to prefix parts that compose assembled parts with a ~.
This prevent using them needlessly (they are not listed with regular parts),
encouraging the use of assembled shortcuts.

But this practice is not ratified by any official LDraw document. As a LDraw
Standards Committee member, I'd like to precise this usage. This is a request
for comments...


There is one document that introduced this.
http://www.ldraw.org/library/tracker/ref/filetypesfaq/

I found we have different problems to solve:
1) Usage of the tilde '~' for files in the \s folder.
2) Usage of the tilde '~' for files in the \parts folder
3) Is the tilde '~' part of the description or only a flag.

I think as follow:
1) As nearly all files in the \s folder do have a leading '~' we should force
that for files in the s\ folder.

2a) I don't feel that we should make things that complicated.
If we have a shortcut for the complete part (as we have today). It is no problem
to figure out which parts to bring into a new file to get what we want.
The other way would blow up the library.
Just if you are working with MLCad it is not a problem to generate what you
need.

2b) To work with LSynth is really make sense to have the ends visible to find
that. Although also here a global shortcut will have all the user needs. And
again it is easy to identify what you need with MLCad.
But we should be consistent in using or not using the '~' for such parts.

3) As the '~' is used as a flag we should also handle it as that, so if there is
a partfile in the \parts folder that carry the '~' in front of the
partdescription the partdescription is assumed to be without the '~' and so the
first word has to be in the category list or a category has to be mentioned (See
requirement: http://www.ldraw.org/Article398.html).
This has also to be decided for the "_" flag for colored parts!

cu
mikeheide

Hi,
I read the above article and is OK, but many parts do not follow these
requirements:
for example part 71427C01.DAT distributed as official is named as assembly but
contains the whole part definition inside with no references to any subparts but
parts\P parts.

In my personal opinion, from a programmer point of view, it could be a good
practice to correctly code as assembly at least those parts that allow
reciprocal movement in between them.
For example a switch has a lever that moves while the base is static; a motor
has an axle that rotate while the rest of the model is static.

Other assembly should be multicolored parts (with the exclusion of patterned
parts), since sometime these color can change.

One more question: what does the suffixes "Dxx" and "Txx" stand for?

regards...

Sergio

The part you mentioned is certified a long time ago and rules changes over the
time. So you will find surely old part in the library that are not according our
current rules.
Also the ...Cxx only advices that the real part is assembled by some parts. They
are not neccessarily also modeled for LDraw.org with subparts but it would be
best practice today.
Suffix "Dxx" is for parts with an sticker already attached. I can not find now
the discussion for that but I am sure that this is correct.
Do you have an example for "Txx"?

cu
mikeheide

   
         
   
Subject: 
Re: Assembled parts, ~ and categories
Newsgroups: 
lugnet.cad
Date: 
Wed, 18 Nov 2009 17:55:40 GMT
Viewed: 
9878 times
  

In lugnet.cad, Sergio Reano wrote:
In lugnet.cad, Michael Heidemann wrote:
In lugnet.cad, Philippe Hurbain wrote:
It is common practice to prefix parts that compose assembled parts with a ~.
This prevent using them needlessly (they are not listed with regular parts),
encouraging the use of assembled shortcuts.

But this practice is not ratified by any official LDraw document. As a LDraw
Standards Committee member, I'd like to precise this usage. This is a request
for comments...


There is one document that introduced this.
http://www.ldraw.org/library/tracker/ref/filetypesfaq/

I found we have different problems to solve:
1) Usage of the tilde '~' for files in the \s folder.
2) Usage of the tilde '~' for files in the \parts folder
3) Is the tilde '~' part of the description or only a flag.

I think as follow:
1) As nearly all files in the \s folder do have a leading '~' we should force
that for files in the s\ folder.

2a) I don't feel that we should make things that complicated.
If we have a shortcut for the complete part (as we have today). It is no problem
to figure out which parts to bring into a new file to get what we want.
The other way would blow up the library.
Just if you are working with MLCad it is not a problem to generate what you
need.

2b) To work with LSynth is really make sense to have the ends visible to find
that. Although also here a global shortcut will have all the user needs. And
again it is easy to identify what you need with MLCad.
But we should be consistent in using or not using the '~' for such parts.

3) As the '~' is used as a flag we should also handle it as that, so if there is
a partfile in the \parts folder that carry the '~' in front of the
partdescription the partdescription is assumed to be without the '~' and so the
first word has to be in the category list or a category has to be mentioned (See
requirement: http://www.ldraw.org/Article398.html).
This has also to be decided for the "_" flag for colored parts!

cu
mikeheide

Hi,
I read the above article and is OK, but many parts do not follow these
requirements:
for example part 71427C01.DAT distributed as official is named as assembly but
contains the whole part definition inside with no references to any subparts but
parts\P parts.

In my personal opinion, from a programmer point of view, it could be a good
practice to correctly code as assembly at least those parts that allow
reciprocal movement in between them.
For example a switch has a lever that moves while the base is static; a motor
has an axle that rotate while the rest of the model is static.

Other assembly should be multicolored parts (with the exclusion of patterned
parts), since sometime these color can change.

One more question: what does the suffixes "Dxx" and "Txx" stand for?

regards...

Sergio

Please understand that the LDraw Parts Library is over 12 years old and
standards evolve over time. Things that were done in 1999, when 71427c01.dat was
created, wouldn't necessarily be done the same way now.

*dNN.dat files are parts with stickers applied
*tNN.dat files are non-standard, and the only representative in the official is
in fact a ~Moved to (i.e re-direct) file  .

Chris

   
         
   
Subject: 
Re: Assembled parts, ~ and categories
Newsgroups: 
lugnet.cad
Date: 
Thu, 19 Nov 2009 08:00:11 GMT
Viewed: 
9848 times
  

requirement: http://www.ldraw.org/Article398.html).

Hi,
I read the above article and is OK, but many parts do not follow these
requirements:
for example part 71427C01.DAT distributed as official is named as assembly but
contains the whole part definition inside with no references to any subparts but
parts\P parts.

In my personal opinion, from a programmer point of view, it could be a good
practice to correctly code as assembly at least those parts that allow
reciprocal movement in between them.
For example a switch has a lever that moves while the base is static; a motor
has an axle that rotate while the rest of the model is static.

Other assembly should be multicolored parts (with the exclusion of patterned
parts), since sometime these color can change.

One more question: what does the suffixes "Dxx" and "Txx" stand for?

regards...

Sergio

Please understand that the LDraw Parts Library is over 12 years old and
standards evolve over time. Things that were done in 1999, when 71427c01.dat was
created, wouldn't necessarily be done the same way now.

*dNN.dat files are parts with stickers applied
*tNN.dat files are non-standard, and the only representative in the official is
in fact a ~Moved to (i.e re-direct) file  .

Chris

I can understand the problem of aged parts, but, again from a programmer
approach, I have to manage both "old" and "new" parts, so it will be very
helpful if all parts can follow the same coding and naming standard.

Please, consider the following example to understand what kind of problem I get:
when I open a part, if it not an assembly I load all its graphics definition in
the same memory storage since the whole parts moves. If it is an assembly,
instead, I will load each "subpart" in different storage since one or more of
them can move while other doesn't.

If something is wrong then it could happen that some mechanism wont move or the
whole part move (like in the motor example) and so the whole model will move
since the motor chassis is "connected" to the rest of the model.

If someone can correct the old parts, I can build and send the list of parts
needing fixes.

Sergio

   
         
   
Subject: 
Re: Assembled parts, ~ and categories
Newsgroups: 
lugnet.cad
Date: 
Thu, 19 Nov 2009 20:10:03 GMT
Viewed: 
10031 times
  

In lugnet.cad, Sergio Reano wrote:
requirement: http://www.ldraw.org/Article398.html).

Hi,
I read the above article and is OK, but many parts do not follow these
requirements:
for example part 71427C01.DAT distributed as official is named as assembly but
contains the whole part definition inside with no references to any subparts but
parts\P parts.

In my personal opinion, from a programmer point of view, it could be a good
practice to correctly code as assembly at least those parts that allow
reciprocal movement in between them.
For example a switch has a lever that moves while the base is static; a motor
has an axle that rotate while the rest of the model is static.

Other assembly should be multicolored parts (with the exclusion of patterned
parts), since sometime these color can change.

One more question: what does the suffixes "Dxx" and "Txx" stand for?

regards...

Sergio

Please understand that the LDraw Parts Library is over 12 years old and
standards evolve over time. Things that were done in 1999, when 71427c01.dat was
created, wouldn't necessarily be done the same way now.

*dNN.dat files are parts with stickers applied
*tNN.dat files are non-standard, and the only representative in the official is
in fact a ~Moved to (i.e re-direct) file  .

Chris

I can understand the problem of aged parts, but, again from a programmer
approach, I have to manage both "old" and "new" parts, so it will be very
helpful if all parts can follow the same coding and naming standard.

Please, consider the following example to understand what kind of problem I get:
when I open a part, if it not an assembly I load all its graphics definition in
the same memory storage since the whole parts moves. If it is an assembly,
instead, I will load each "subpart" in different storage since one or more of
them can move while other doesn't.

If something is wrong then it could happen that some mechanism wont move or the
whole part move (like in the motor example) and so the whole model will move
since the motor chassis is "connected" to the rest of the model.

If someone can correct the old parts, I can build and send the list of parts
needing fixes.

Sergio

Maybe you are trying to interpret too much from the naming convention. A
composite part (*cNN.dat) isn't necessarily comprised of parts that can move
relative to each other, It might just be made of two or more separately moulded
elements that are connected in a fixed configuration. Even if the separate
elements are moveable, there is no assurance that the rotation origon can be
deduced. So I think you have some big challenges here.

One solution might be to extend the metadata in the parts files, or include
separate "connection" information in the library in some other form. This has
been talked about before as an "LDraw Connections Database" project.

Please be careful not to misuse the term "subpart". That has a semantic meaning
in LDraw that does not mean "constituent part". The term is used to refer to a
separate file of re-used lines and surfaces, that is rarely, if ever, a closed
solid.

If you have analysed the library to identify which composite parts are not built
of parts, then please post it so that authors can work on bringing the library
up to the current conventions. Or maybe you could even take in some of that work
yourself?

Chris

 

©2005 LUGNET. All rights reserved. - hosted by steinbruch.info GbR