Many ui features for geometry nodes need access to information generated
during evaluation:
* Node warnings.
* Attribute search.
* Viewer node.
* Socket inspection (not in master yet).
The way we logged the required information before had some disadvantages:
* Viewer node used a completely separate system from node warnings and
attribute search.
* Most of the context of logged information is lost when e.g. the same node
group is used multiple times.
* A global lock was needed every time something is logged.
This new implementation solves these problems:
* All four mentioned ui features use the same underlying logging system.
* All context information for logged values is kept intact.
* Every thread has its own local logger. The logged informatiton is combined
in the end.
Differential Revision: https://developer.blender.org/D11785
This adds a viewer node similar to the one in the compositor.
The icon in the headers of nodes is removed because it served
the same purpose and is not necessary anymore.
Node outputs can be connected to the active viewer using
ctrl+shift+LMB, just like in the compositor. Right now this collides
with the shortcut used in the node wrangler addon, which will
be changed separately.
As of now, the viewed geometry is only visible in the spreadsheet.
Viewport visualization will be added separately.
There are a couple of benefits of using a viewer node compared
to the old approach with the icon in the node header:
* Better support for nodes that have more than one geometry output.
* It's more consistent with the compositor.
* If attributes become decoupled from geometry in the future,
the viewer can have a separate input for the attribute to visualize.
* The viewer node could potentially have visualization settings.
* Allows to keep "visualization points" around by having multiple
viewer nodes.
* Less visual clutter in node headers.
Differential Revision: https://developer.blender.org/D11470
* Reduce code duplication.
* Give methods more standardized names (e.g. `move_to_initialized` -> `move_assign`).
* Support wrapping arbitrary C++ types, even those that e.g. are not copyable.
This makes the parts where a node is locked more explicit. Also, now the thread
is isolated when the node is locked. This prevents some kinds of deadlocks
(which haven't happened in practice yet).
This namespace groups threading related functions/classes. This avoids
adding more threading related stuff to the blender namespace. Also it
makes naming a bit easier, e.g. the c++ version of BLI_task_isolate could
become blender::threading::isolate_task or something similar.
Differential Revision: https://developer.blender.org/D11624
After looking into task isolation issues with Sergey, we couldn't find the
reason behind the deadlocks that we are getting in T87938 and a Sprite Fright
file involving motion blur renders.
There is no apparent place where we adding or waiting on tasks in a task group
from different isolation regions, which is what is known to cause problems. Yet
it still hangs. Either we do not understand some limitation of TBB isolation,
or there is a bug in TBB, but we could not figure it out.
Instead the idea is to use isolation only where we know we need it: when
holding a mutex lock and then doing some multithreaded operation within that
locked region. Three places where we do this now:
* Generated images
* Cached BVH tree building
* OpenVDB lazy grid loading
Compared to the more automatic approach previously used, there is the downside
that it is easy to miss places where we need isolation. Yet doing it more
automatically is also causing unexpected issue and bugs that we found no
solution for, so this seems better.
Patch implemented by Sergey and me.
Differential Revision: https://developer.blender.org/D11603
While this preprocessing does take some time upfront,
it avoids longer lookup later on, especially as nodes get
more sockets.
It's probably possible to make this more efficient in some cases
but this is good enough for now.
A deadlock could happen under certain circumstances when
geometry nodes is used on multiple objects.
Once T88598 is resolved, multi-threading can be enabled again.
Differential Revision: https://developer.blender.org/D11405
The old geometry nodes evaluator was quite basic and missed many features.
It was useful to get the geometry nodes project started. However, nowadays
we run into its limitations from time to time.
The new evaluator is more complex, but comes with new capabilities.
The two most important capabilities are that it can now execute nodes in
parallel and it supports lazy evaluation.
The performance improvement by multi-threading depends a lot on the specific
node tree. In our demo files, the speedup is measurable but not huge. This
is mainly because they are bottlenecked by one or two nodes that have to be
executed one after the other (often the Boolean or Attribute Proximity nodes)
or because the bottleneck is multi-threaded already (often openvdb nodes).
Lazy evaluation of inputs is only supported by the Switch node for now.
Previously, geometry nodes would always compute both inputs and then just
discard the one that is not used. Now, only the input that is required
is computed.
For some more details read D11191, T87620 and the in-code documentation.
Differential Revision: https://developer.blender.org/D11191
Those were mostly just left over from previous work on particle nodes.
They solved the problem of keeping a reference to an object over
multiple frames and in a cache. Currently, we do not have this problem
in geometry nodes, so we can also remove this layer of complexity
for now.
This is a first step towards T87620.
It should not have any functional changes.
Goals of this refactor:
* Move the evaluator out of `MOD_nodes.cc`. That makes it easier to
improve it in isolation.
* Extract core input/out parameter management out of `GeoNodeExecParams`.
Managing this is the responsibility of the evaluator. This separation of
concerns will be useful once we have lazy evaluation of certain inputs/outputs.
Differential Revision: https://developer.blender.org/D11085
