[Bf-committers] The Story Of My Attempts At Contributing Code To Blender

[Dalai Felinto]

Hi Ryan,
Thanks for your email.

I will talk to Bastien to understand better the decision process for this
particular patch. See what caused your patch to be abandoned, and if there
is room for further performance improvements. I will get back to you here.

Furthermore, you brought a few points that the Blender project has to
improve:

* Communication of the modules agendas.
* Module to be more open to contributors.
* Patch review process (e.g., clear process or assigning, set expectations
upfront, better communication).

As a rule of thumb any developer who is driven to collaborate to Blender
overall agenda and shows the dedication and competence should be welcomed
into the modules. Even for modules where the bar is a bit higher, such as
the core module [1].

All in all this comes in in a good time. In a few weeks Thomas Dinges will
start helping to coordinate the online development community. And this is a
very clear use case of what he can look at to help for improvements.

Meanwhile as a general rule if a module is not working well this can be
escalated to the bf-admins [2]. As a last resource if someone think that
the bf-admins are not addressing things properly or in a fashionable time,
it can escalate further to Ton.

[1] -
https://code.blender.org/2021/02/module-teams-for-core-blender-development/
[2] - https://wiki.blender.org/wiki/Modules#Blender

Regards,
-Dalai-
--------------------------------------------------------------------
Dalai Felinto - dalai at blender.org - www.blender.org
Blender Development Coordinator
Buikslotermeerplein 161, 1025 ET Amsterdam, the Netherlands


Op wo 11 aug. 2021 om 01:17 schreef Ryan Inch via Bf-committers <
bf-committers at blender.org>:

> To the core Blender developers.
> Hello again, Collection Manager dev here.
> Let me start off by saying that I care a lot about Blender, it's been a
> huge influence on my life and an inspiring story of the little DCC app
> that could, and I want nothing but the best for it. So it highly saddens
> me that I feel I need to write this email.
>
> I've been a part of the Blender community and writing add-ons for it for
> eight years and a user of Blender for even longer.  I love the power it
> gives me to create, and have always tried to give back with what I have
> to give (Unfortunately, money is not one of those ways, so I have
> contributed code, feedback, and support instead).
>
> In 2019 I separated the Collection Manager out of a larger add-on and
> submitted it to be included in Blender as a bundled add-on on the advice
> of Brendon Murphy (meta-androcto).  Soon after my submission, I was
> contacted by Paul Kotelevets (1D_Inc) who expressed the short comings of
> the current collections system for complex scene setup and precise
> modeling that requires multiple reference images.  Together, along with
> others who gave feedback, we have advanced the usability of Blender for
> complex setups and increased the capabilities of the new collection
> system.  When I started this project I assumed that it would be highly
> welcomed, because collections were one of the pillars of the 2.8
> project, however, it was mostly ignored.  Still, I continued on with the
> project because it was useful to me and was essential to others for
> their jobs.
>
> In the year and a half I've worked on the project, I've become pretty
> familiar with the python side of collections and layer collections, but
> during that time I ran into problems that I thought would be better
> solved on the C side of Blender, so I spent ~6 months familiarizing
> myself with layer collections and attempting to solve some of the
> problems I'd run into, and then ultimately trying to stabilize layer
> collections as a first step to further improvements.  I submitted three
> patches during this time, one of which went nowhere (and rightly so),
> one of which was a draft and that I used to ask for help when stuck (to
> which was replied: Thanks for the patch, but it's up to you to present a
> working code, otherwise it's likely a loss of time for everybody...),
> and then a final one, which did contain working code.
>
> I submitted the final patch on November 18th 2020 and assigned Bastien
> Montagne, Brecht Van Lommel, and Dalai Felinto as reviewers; two months
> later I updated the patch to the latest master and linked a good test
> file I had made; ~2 weeks after that, Bastien responded that the patch
> hadn't been forgotten and that he'd just had a lot on his plate; a few
> days after this Hans Goudey (HooglyBoogly) reviewed the patch and
> provided some really good comments (he didn't have to do this and I'm
> really grateful to him), which I then addressed a couple weeks later (I
> had been busy and things didn't seem urgent); three months later I
> updated the patch to the latest master again; and then almost two months
> after that it was abandoned by Bastien who had apparently just committed
> his own solution.
>
> As you might imagine, this was fairly distressing to me as I had put a
> lot of time and effort into creating and then maintaining it.  I had
> been content to be patient and not push for my patch, because I thought
> it was of a low priority and I knew from various sources of Blender
> communication that Bastien had been very busy and I didn't want to add
> to the stress he was under.  So, after the patch was closed, I looked
> into the one that replaced it and at Bastien's weekly reports to try and
> figure out what had happened.
>
> On inspection of Bastien's weekly reports, I found that he had been
> working on his own solution for a month or so, but I hadn't connected
> the dots because I thought he was working on stuff for library overrides
> and that if he had needed something to preserve layer collections he
> would have used the already working code that had been sitting in the
> patch tracker for six months (or if a different direction was required,
> told me and brought me onboard with developing the new patch).  And when
> I looked at the patch that replaced mine, I found a comment by Brecht
> saying it was "Great to see this tackled.", as if now that a "real"
> programmer was working on it, it was suddenly much more important and
> welcomed.
>
> There are two issues here, with the first being how everything was
> handled, the lack of communication and the disregard for the time I
> spent attempting to contribute.  I have seen in official Blender
> communications that one of the goals of Blender is to onboard new
> developers, this is a perfect example of how not to do that. Campbell
> Barton once said something in IRC about GSoC students that I have always
> found inspiring:
>
> "Typically for students who don't know what they want they ask a lot of
> Q's... and never get involved.
> (sounds a bit negative... just my experience tho)
> Basically they waste our time.
> People who are motivated don't wait for others to tell them what to do,
> they start interesting projects themselves."
>
> Now I'm not a GSoC student, but I started an interesting project, and
> filled a gap that the core developers didn't have the time to address.
> I didn't ask a lot of questions, because I'm pretty good at figuring
> things out on my own, and I attempted to get involved. When I started, I
> expected to be welcomed and onboarded by a great open source project
> that was in need of more contributors and that I could work with to
> improve a tool I care deeply about, but what I found was a project that
> paid little attention to my contributions, did nothing to onboard me,
> seems to care little for community contributions, and was mostly
> unwilling to work with me.
>
> The second issue here is with the code of the patch (D12016) that was
> approved over mine (D9599).  While as far as I can tell, they are
> functionally equivalent, Bastien's is much slower than mine, especially
> when it comes to many layer collections under one parent.  From my tests
> (debug, lite build, with Bastien's CLOGGING removed so as to match my
> patch) the average time it took to resync 1000 collections when
> configured so that each of the 1000 had 1 child was 612 microseconds for
> Bastien's and 261 microseconds for my patch.  That's almost 2.5 times
> slower for his patch.  When the 1000 collections were configured as a
> flat list under the scene collection, Bastiens took on average 22290
> microseconds, while mine, on average, took only 252 microseconds.
> That's almost 88.5 times slower for his patch.
>
> You may be thinking that 1000 collections is unrealistically high and
> that no one actually uses that many, but Paul Kotelevets (a diamond
> level sponser, BTW) has told me that he regularly uses 7-9,000
> collections in his work, so my test case is on the low side and the
> performance costs of Bastien's patch will be even greater than what I
> have outlined here.
>
> I believe the performance problems with Bastien's patch stem mainly from
> three places, the BLI_findptr which is used to check whether the layer
> collection is valid as a child when generating the layer collection tree
> wrapper with additional data, the method that is used when searching
> through the wrapper, and the fact that each layer collection has to be
> searched out from the wrapper, even when it is already in sync with the
> collection tree.  The problem with all this searching is that for each
> collection it tries to find under the current parent it has to loop over
> all the previous collections under that parent, and this happens in 2
> distinct areas.  And I believe this is also why it's so much slower when
> all the collections are under one parent.
>
> I think the reason mine is so much faster is that it does much less
> searching.  My patch processes the layer collection tree in a depth
> first search and finds only the invalid layer collections and stores
> them in order, then the collection tree and layer collection tree are
> walked through in tandem, re-linking the valid layer collections as it
> goes, moving the invalid layer collections to their new positions when
> needed, and then removing the invalid layer collections from the
> original processed list after they've been added to the new layer
> collection tree.  As little searching as possible is done, with the
> initial order of the layer collections, the fact that they are invalid,
> and the fact that the collection associated with that layer collection
> matches the collection in the collection tree provides the needed data
> to relink them successfully.
>
> I will admit that there's always the possibility that my patch doesn't
> handle some corner case, but nothing was identified in my own testing or
> the review given to my patch, so I think it's safe to say the only
> difference between the two is the underlying method, the performance,
> and the authors.
>
> Given what has happened I'd like to just wash my hands of this and
> forget wasting all of our time with me trying to contribute to the C
> side of Blender and just stick to developing my add-on for those that
> rely on it, but I can't, the performance implications are too large and
> I can't in good conscience ignore this.  I'm willing to try and work
> with you on this, whether that's with my patch, or on Bastien's to
> improve his patch's performance (if it is uncovered that there is some
> unsolvable limitation with mine), but I hope I have conveyed that a much
> better outcome with much less work for all parties could have been
> achieved had I been worked with, instead of around.
>
> Sincerely yours,
> an offboarded developer.
>
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