I just stumbled over files on the PT containing
0 BFC NOCLIP
...
0 BFC CLIP
sections, for example
https://www.ldraw.org/cgi-bin/ptdetail.c...02ap03.dat
I think we need to decide if those sections shall be
* kept or
* removed.
They usually enclose the patterned areas of a part.
I think the reason why they were added (probably long time ago) was
that somebody thought "hmm. these patterns could be visible from behind
when the part itself is being used in a transparent color".
However, that reasoning is based on a wrong assumption I think.
Maybe the tools of older times needed such statements, but today, these lines are not necessary.
Especially it makes no sense to just include the pattern by those lines.
If the argumentation towards having these lines would be correct, then the whole part
would need to be BFC NOCLIP.
But as said, the reasoning behind the addition of these lines is probably wrong I think:
As soon as a part is using transparent portions, these portions allow to see other surfaces "from behind".
It does not matter whether those other surfaces are colored (patterns) or color 16.
Therefore, 3D rendering software anyway must have an implementation for dealing with that problem.
Usually its solution will be to simply turn off BFC at all for parts that contain transparent portions.
That would be the only way to get a correct rendering for all such parts as a general solution.
Therefore it is not necessary that such parts individually and additionally enclose some of their implementation by
0 BFC NOCLIP.
Doing that is a kind of "poor man's solution" to the overall 3D rendering problem just described.
And most of the current files on the PT incompletely solve that problem,
because they do not include their color 16 surfaces in that section.
It follows:
these sections should be removed I think.
0 BFC NOCLIP
...
0 BFC CLIP
sections, for example
https://www.ldraw.org/cgi-bin/ptdetail.c...02ap03.dat
I think we need to decide if those sections shall be
* kept or
* removed.
They usually enclose the patterned areas of a part.
I think the reason why they were added (probably long time ago) was
that somebody thought "hmm. these patterns could be visible from behind
when the part itself is being used in a transparent color".
However, that reasoning is based on a wrong assumption I think.
Maybe the tools of older times needed such statements, but today, these lines are not necessary.
Especially it makes no sense to just include the pattern by those lines.
If the argumentation towards having these lines would be correct, then the whole part
would need to be BFC NOCLIP.
But as said, the reasoning behind the addition of these lines is probably wrong I think:
As soon as a part is using transparent portions, these portions allow to see other surfaces "from behind".
It does not matter whether those other surfaces are colored (patterns) or color 16.
Therefore, 3D rendering software anyway must have an implementation for dealing with that problem.
Usually its solution will be to simply turn off BFC at all for parts that contain transparent portions.
That would be the only way to get a correct rendering for all such parts as a general solution.
Therefore it is not necessary that such parts individually and additionally enclose some of their implementation by
0 BFC NOCLIP.
Doing that is a kind of "poor man's solution" to the overall 3D rendering problem just described.
And most of the current files on the PT incompletely solve that problem,
because they do not include their color 16 surfaces in that section.
It follows:
these sections should be removed I think.