LDraw.org Discussion Forums

Full Version: Importance of stud orientation?
You're currently viewing a stripped down version of our content. View the full version with proper formatting.
While creating new LDraw parts I've paid particular attention to the orientation of the studs to ensure that the parts look as accurate as possible.

One thing I've noticed in the LDraw library (and also the LGEO library, but that's another matter) is that although an existing part may be near-perfect, sometimes the orientation of the studs is incorrect.

This is most apparent when using something like LDView, where stud logos are oriented based on the stud.dat's orientation in the LDraw part file. And when LDView exports a model to POV-Ray and uses LGEO studs on non-LGEO parts, the issue carries over.

My question is this: Should existing LDraw parts be resubmitted to the Parts Tracker (via email, of course) just to fix something like stud orientation?

[Incidentally, my current solution to ensure stud orientation is correct is a modification to stud.dat which incorporates the (uncertified) logo.dat primitive, so the LEGO logo is always visible, even in programs like MLCad.]
despite me being also a fan of correct stud orientation,
and also using the same technique as you,
I would like to oppose to the idea of submitting parts just for _that_ reason
to the PT, as this would create (again) a huge pile of todos for us reviewers,
and we cannot really cope with the current workload already.

on the other hand I understand your approach, and would not really like a "forbidding" of doing so.

question is if you would like to dedicate your precious energy maybe to helping us review
the existing pile of parts.......
I say no. Stud logos are not defined in the spec. Until such time as they are they should not be considered official in any way and therefore should not be the cause of a hold or resubmit.
I agree with answers so far. Correct orientation is a "best effort" at part authoring or when there is a modification of the part. Just wanted to add that several parts changed stud orientation when LEGO re-tooled the molds...
This is an example of a situation in which a lighter-weight part editing process would benefit LDraw. Here we have a person volunteering to make improvements to the library, but being told not to because the review process just makes it too cumbersome to integrate those improvements.

Thank you all for your clarification. I guess there is a chance that adding a logo to every stud or part that requires one could cause a slowdown during display, although most home machines would have progressed in computational power since the initial creation of the LDraw system.

And, as Steffen said, it would be time-consuming to check all existing parts.

Steffen Wrote:question is if you would like to dedicate your precious energy maybe to helping us review
the existing pile of parts...

I have requested reviewer access and, when it is granted, will certainly do my best to review what I can. (My LDraw knowledge is not as in depth as a lot of existing Parts Tracker reviewers.)

Orion Pobursky Wrote:Stud logos are not defined in the spec.

Is there a chance that this is likely to change? Although programs like LDView can superimpose stud logos on instances of stud.dat, there are wheel rims/hubs that have the logo which LDView does not display. I know it's currently personal preference, but I'm a fan of the studs logos showing where they should.

Philippe Hurbain Wrote:Just wanted to add that several parts changed stud orientation when LEGO re-tooled the molds...

I've certainly noticed this when researching stud orientation for LGEO parts. The oddest example I found was the yellow part shown here.
I don't understand. Lighter-weight editing process or lighter-weight review process?
In order for any edit to be disseminated, it must go through the review process. So I would describe the review as a step in the overall edit process. But whatever terms are used, the context of the discussion was the review and the time burden that review entails.

Owen, the addition of stud logos can be done by several techniques,
and which one you choose depends on your desires.
Our library just has to make sure that you _can_ place logos on the studs when wanted.
The currently used techniques are various:
(a) some people - like me - replace their stud.dat by a file which adds logo.dat to it, so a logo appears on all studs in all tools as "lines"
(b) some tools - like LDView - can use lowlevel graphics functions like texture mapping to map a logo onto studs
© when doing a 3D rendering export - like for example to POVRay - logos can be modeled in various ways, e.g. as thin cylindric lines, as real 3D objects, or as a bitmap projection
(d) tools - like MLCad - have user options by which you can pick the detailing level of stud display. you can leave them completely away, you can render them as a single, thin vertical line, you can render them roughly ("fast-draw") or nicely etc.pp.

So as you see, our library doesn't hardcode how the studs get displayed.
It just makes sure that its logic structure allow you to apply any desired technique.
Just another Good Thing ™ of our library IMHO.
Were Owen (thanks for the offer Smile ) to edit these parts and make a zip file available I'd happily link to it from the main site. But the official library does have to be checked over carefully. All it takes is an accidental delete of a line to break a part so even a change of stud orientation needs to be looked at twice just in case.

Do you have some constructive ideas about how to streamline the review part of the update process? I think it makes sense for two reviewers to check any change, and these days the admin review is not usually a roadblock.

I have already implemented an admin fasttrack review for description only changes.
I can put together a few of the parts that I've found and edited, and attach a link this weekend.

Most of the edits are for accuracy, although I have a couple of "~" parts which just create a more consistent appearance in the parts that they're used in.
Please send these to me to put through the Parts Tracker. I'd rather not have another place for people to download updated versions of parts. If the only changes are the orientation of stud primitives then I think they could be fast-tracked.
I agree.
That change is as simple/trivial as renaming.
Before sending Chris the files, would replacing multiple studs with stud groups also be considered "simple/trivial"? That's literally the only other change I've made to some of these files (where appropriate).
to me, yes - YMMV
I think, that it's such a simple task, that we don't need the certify process.
But that's only my opinion...