Note: This is an archived version of the Blender Developer Wiki. The current and active wiki is available on wiki.blender.org.

Fortnightly Updates on Depsgraph Refactor Dev Fund Work

Weeks 7 & 8 (Jan 12 - Jan 23)

Summary of past 2 weeks:

Rigidbody sims now work
Grease Pencil animation is updated by the depsgraph
Worked on overhauling how IK chains get added/handled (for fixing issues when there are dependencies between two bones within the same IK chain). This is proving to be tougher than expected to crack, with Koro continuing to be a hotbed of weird and wonderful bugs!
Did some preliminary investigations into alternatives to graphviz for graphical debugging of the graphs, since it's currently impossible to debug what's going on in the production rigs when they fail. OGDF seems to be promising...
Inserting keyframes for the first time on a datablock tags the depsgraph for rebuilding now (so that animation works, as it needs a link to the timesource node)

Non-Depsgraph (Gooseberry Fixes):

Better volume preservation for Spline IK
Fix for joining armatures not retaining (3df93d0) and fixing up drivers (a730cda)

Summary of past 2 weeks:

Removed redundant verify_entry_exit_operations() in favour of manually defined entry/exit points per component where needed
Fixed problem where the keys for driver operations were not unique enough to identify array elements (e.g. location.x and location.y were treated as the same)
Drivers for armature bone settings now work
Shapekey drivers and animation now work
Pole targets for IK chains now work
Finished reviewing how pose bones are added to the depsgraph
Various code cleanups - Removing redundant code, and started checking on all places where geometry drivers are needed
Created some more test cases + testing various open movie rigs to check for bugs

General Development:

Next Targets:

Finish checking on all geometry refs to ensure that they are being set up correctly
Review RNAPathKey lookups
Get rigidbody sims working in depsgraph
Check that animation and drivers on materials/lamps/shading datablocks gets handled correctly
Try to get all openmovie rigs and shot files properly functional

Highlights of past 2 weeks:

Refactored the way that lookups for OperationNodes was getting done to make the code easier to maintain and hopefully perform better too.
- Replaced strings with enum constants, and adjusted OperationKey/etc.
- Fixed all the existing code to use these identifiers

Refactored in/outlink relationship lists back to the DepsNode base class where it belongs

Object-level (transforms) are now done using granular callbacks. The constraint stack is still evaluated as a single operation for now though, since we don't have temp storage for that stuff.

Various improvements to make it easier to debug what's going on
- Added operators in header to quickly refresh/rebuild, dump summary stats (i.e. number of nodes/relations), and for exporting graphs
- Added more meaningful debug print info for various node types and their lookup keys, making it easier to figure out what is failing and why

Christmas holidays/short break/fuzzy-headed-days/checking-on-2.73-release-things

Next Targets:

Finish reviewing/refactoring code for building graphs for armatures. There's still some confusing weirdness going on here (especially regarding IK vs non-IK chains) that isn't that nice

Get RNAKey lookups working, and fix how that integrates with drivers (e.g. for shapekeys, and a few other similar areas)

Review and fix the way that geometry updates are handled
- Double check verify_entry_exit_ops() concerns raised by Sergey
- Review where/how "path" data gets calculated for curves
- Split more of the code out from the ubereval
- Check on which component these operations should belong to

Got the ``depsgraph_refactor branch compiling on mingw64, after working through heaps of compatibility issues with needing to compile the code with C++11 extensions.

With Sergey's assistance, got tools/workflow for testing whether the graphs are getting built correctly

Fixed the way that animation is represented in the depsgraph. Action + NLA need to be evaluated/considered as a black box

Fixed bugs with some driver targets not getting hooked up correctly (e.g. objects for transform channels)

Got interleaved bone <-> driver evaluation working. For example, it is now possible to have one bone in an armature driving the constraint influence of another bone in the same armature.

Tried to test koro.blend and Pataz caterpillar.blend (from Gooseberry teaser), and export the graphs of these.
- There are still many broken things in these files: missing relationships, sluggish updates (hopefully just due to the amount of logging we're doing), some malfuncting updates, memory leaks with IK solver trees not getting freed.
- As a word of warning, the graphviz graphs for these cannot be drawn using ``dot and must instead be drawn using ``neato, or else it will just take over half and hour of intensive processing before it crashes. Even with neato, this is quite slow.

Spent time trying to understand the whole ComponentKey/OperationKey/RNAKey system and how that relates to some oddities surrounding some cases where relationships are not getting built. Began investigating some cleaner alternatives (e.g. restoring the enum for operation types instead of using dynamic/mutable strings for these kinds of lookups)

Also spent time trying to double check the core code in many places. Identified a number of confusing areas which need some attention/cleanup, as the current state will likely pose maintenance issues in future.

Spent time trying to track down a bug where simple bone chains aren't getting added correctly (but those with IK chains so far still seem to work ok). This exercise revealed the confusing nature of some of the code currently there, along with a number of other small todo's to investigate.