[Soc-2013-dev] Weekly Report #2 Depsgraph Refactor

[Joshua Leung]

Hi All,

== This Week ==
I spent most of the week polishing/writing up a bunch of notes about
various fragments/topics about various design issues and
considerations. Links to these are included at the end of this report,
and are also linked from the main wiki page (TODO: copy over the
contents to wiki pages; I'll probably leave this for September, when
I'll almost certainly be fully occupied by a paper submission
deadline).

In the process of writing these, I now have a clearer perspective on
some aspects of the design which had previously still been quite
fuzzy/tricky to pin down (notably, how exactly to group/keep track of
links between coarse and fine grained nodes).

As an added bonus, we now finally have a nice intro to how the
internals of the armature evaluation process works (at last! - and
just before it's soon to get a good shake-up), and some annotated
reading material for anyone getting into this (dependency graph) work.
:)


== Next Week ==
I'm currently aiming to have an initial design doc/proposal (maybe not
fully fleshed out with regards to a few areas) outlining the general
direction of the system design ready by the end of this weekend (+/-
1-2 days). Core devs (and in particular, those involved with the
various physics sims) and riggers are strongly encouraged to have a
good look and try to pick up any problems which we may run into. At
this stage, I'll probably be posting this to the main developers list,
though it might be better to move/hold the discussion on the
bf-animsys (http://lists.blender.org/mailman/listinfo/bf-animsys)
list, which was originally set up for discussions about animation
system stuff during early 2.5 days.

I'll also start prototyping/mocking up the core data-structures/API's
for implementing the proposed design. Hopefully I won't encounter any
significant roadblocks here requiring a serious rethink about where we
go with this. It's always a possibility though with something like
this.

Depending on how I go for time, more likely than not, I'll have a few
more posts up examining some of the trickier issues (e.g. physics
integration, layer-update stuff).


== Questions ==
Which list should we hold feedback/discussions about the design on?
bf-developers/committers or bf-animsys? In any case, I'll probably
just cross-post the initial link(s) across both.


== Links ==
In chronological/logical order:
* http://aligorith.blogspot.com/2013/06/depsgraph-know-thy-enemy.html
* http://aligorith.blogspot.com/2013/06/depsgraph-granularity-problem.html
* http://aligorith.blogspot.com/2013/06/depsgraph-whats-in-node.html
* http://aligorith.blogspot.com/2013/06/depsgraph-id-groups.html


Regards,
Joshua