The contents of the ModifierEvalContext struct are constant while iterating
over the modifier stack. The struct thus should be only created once, outside
any loop over the modifiers.
This commit introduces `EditMeshData`. The fields in this struct are
extracted from `EditDerivedBMesh` into their own struct `EditMeshData`,
which can then also be used by the `Mesh` struct. This allows passing
deformed vertices efficiently to the draw routines.
The modifier code constructs a new Mesh instead of writing to ob->data;
even when ob->data is a CoW copy, it can still be used by different
objects and thus shouldn't be modified by a modifier.
Makes the follow changes:
- Add new `deform*` and `apply*` function pointers to `ModifierTypeInfo` that take `Mesh`, and rename the old functions to indicate that they take `DerivedMesh`. These new functions are currently set to `NULL` for all modifiers.
- Add wrapper `modifier_deform*` and `modifier_apply*` functions in two variants: one that works with `Mesh` and the other which works with `DerivedMesh` that is named with `*_DM_depercated`. These functions check which type of data the modifier supports and converts if necessary
- Update the rest of Blender to be aware and make use of these new functions
The goal of these changes is to make it possible to port to using `Mesh` incrementally without ever needing to enter into a state where modifiers don't work. After everything has been ported over the old functions and wrappers could be removed.
Reviewers: campbellbarton, sergey, mont29
Subscribers: sybren
Tags: #bf_blender_2.8
Differential Revision: https://developer.blender.org/D3155
The depsgraph was always created within a fixed evaluation context. Passing
both risks the depsgraph and evaluation context not matching, and it
complicates the Python API where we'd have to expose both which is not so
easy to understand.
This also removes the global evaluation context in main, which assumed there
to be a single active scene and view layer.
Differential Revision: https://developer.blender.org/D3152
2.8x branch added bContext arg in many places,
pass eval-context instead since its not simple to reason about what
what nested functions do when they can access and change almost anything.
Also use const to prevent unexpected modifications.
This fixes crash loading files with shadows,
since off-screen buffers use a NULL context for rendering.
Note that some little parts of code have been dissabled because eval_ctx
was not available there. This should be resolved once DerivedMesh is
replaced.
Better to have clear way to tell whether flag is parameter for
BKE_library_foreach_ID_link(), parameter for its callback function, or
return value from this callback function.
Also, fix own stupidity, no need to define ID callback in case we only have objects,
calling code knows to fallback to `foreachObjectLink()` when `foreachIDLink()` is missing...
This commit integrates the work done so far on the new dependency graph system,
where goal was to replace legacy depsgraph with the new one, supporting loads of
neat features like:
- More granular dependency relation nature, which solves issues with fake cycles
in the dependencies.
- Move towards all-animatable, by better integration of drivers into the system.
- Lay down some basis for upcoming copy-on-write, overrides and so on.
The new system is living side-by-side with the previous one and disabled by
default, so nothing will become suddenly broken. The way to enable new depsgraph
is to pass `--new-depsgraph` command line argument.
It's a bit early to consider the system production-ready, there are some TODOs
and issues were discovered during the merge period, they'll be addressed ASAP.
But it's important to merge, because it's the only way to attract artists to
really start testing this system.
There are number of assorted documents related on the design of the new system:
* http://wiki.blender.org/index.php/User:Aligorith/GSoC2013_Depsgraph#Design_Documents
* http://wiki.blender.org/index.php/User:Nazg-gul/DependencyGraph
There are also some user-related information online:
* http://code.blender.org/2015/02/blender-dependency-graph-branch-for-users/
* http://code.blender.org/2015/03/more-dependency-graph-tricks/
Kudos to everyone who was involved into the project:
- Joshua "Aligorith" Leung -- design specification, initial code
- Lukas "lukas_t" Toenne -- integrating code into blender, with further fixes
- Sergey "Sergey" "Sharybin" -- some mocking around, trying to wrap up the
project and so
- Bassam "slikdigit" Kurdali -- stressing the new system, reporting all the
issues and recording/writing documentation.
- Everyone else who i forgot to mention here :)
