Currently the link limit of sockets is stored in bNodeSocket->limit.
This allows for a lot of flexibility, but is also very redundant.
In every case I've had to deal with so far, it would have "more correct"
to set the link limit per socket type and not per socket. I did not enforce
this constraint yet, because the link limit is exposed in the Python API,
which I did not want to break here.
In the future it might even make sense to only support only three kinds of link limits:
a) no links, b) at most one link, c) an arbitrary number links links. The other link
limits usually don't work well with tools (e.g. which link should be removed when a new
one is connected?) and is not used in practice. However, that is for another day.
Eventually, I would like to get rid of bNodeSocket->limit completely and replace it
either with fixed link limits or a callback in bNodeSocketType.
This patch consists of three parts:
**1. Support defining link limit in socket type**
This introduces a new `nodeSocketLinkLimit` function that serves as an indirection to
hide where the link limit of a socket is defined.
**2. Define link limits for builtin sockets on socket type**
Data sockets: one input, many outputs
Virtual sockets: one input, one output
Undefined sockets: many inputs, many outputs (to avoid that links are removed when the type of the socket is not known)
**3. Remove `bNodeSocketTemplate->limit`**
This wasn't used anymore after the second commit. Removing it simplifies socket definitions
in hundreds of places and removes a lot of redundancy.
Differential Revision: https://developer.blender.org/D7038
Reviewers: brecht
BF-admins agree to remove header information that isn't useful,
to reduce noise.
- BEGIN/END license blocks
Developers should add non license comments as separate comment blocks.
No need for separator text.
- Contributors
This is often invalid, outdated or misleading
especially when splitting files.
It's more useful to git-blame to find out who has developed the code.
See P901 for script to perform these edits.
This would lead to sock.default_value pointing to the wrong data type,
possibly causing crashes. Unfortunately, this bug will still exist for
older Blender versions that try to load newer files, which makes
changing the type of a node socket problematic.
Implements a more flexible internal connect function for standard nodes
(compositor, shader, texture). Allow feasible datatype connections by
priority.
The priorities for common datatypes in compositor, shader and texture
nodes are encoded in a simple function. Certain impossible connections
(e.g. color -> cycles shader) are excluded by giving them -1 priority.
Priority overrides link status: If a higher priority input can be found,
this will be used regardless of link status. Link status only comes into
play for inputs with same priority.
Reviewers: brecht
CC: sebastian_k
Differential Revision: https://developer.blender.org/D356
The sanity check for copying socket default value was using the socket
idname for type compatibility checks, which is too strict. Subtypes
would not be recognized as copyable, but since only the plain data type
is needed below this is all that needs to be checked.
That alone would not cause crash (just missing default value copy),
but the tree view template was messing with the default_value DNA
directly by freeing it in advance, which is not necessary and should
be left to blenkernel when freeing the node. Otherwise this would
leave the node invalid without a default_value if the copy function
bails out.
texture coordinate that should automatically use the default normal or texture
coordinate appropriate for that node, rather than some fixed value specified by
the user.
PyNodes opens up the node system in Blender to scripters and adds a number of UI-level improvements.
=== Dynamic node type registration ===
Node types can now be added at runtime, using the RNA registration mechanism from python. This enables addons such as render engines to create a complete user interface with nodes.
Examples of how such nodes can be defined can be found in my personal wiki docs atm [1] and as a script template in release/scripts/templates_py/custom_nodes.py [2].
=== Node group improvements ===
Each node editor now has a tree history of edited node groups, which allows opening and editing nested node groups. The node editor also supports pinning now, so that different spaces can be used to edit different node groups simultaneously. For more ramblings and rationale see (really old) blog post on code.blender.org [3].
The interface of node groups has been overhauled. Sockets of a node group are no longer displayed in columns on either side, but instead special input/output nodes are used to mirror group sockets inside a node tree. This solves the problem of long node lines in groups and allows more adaptable node layout. Internal sockets can be exposed from a group by either connecting to the extension sockets in input/output nodes (shown as empty circle) or by adding sockets from the node property bar in the "Interface" panel. Further details such as the socket name can also be changed there.
[1] http://wiki.blender.org/index.php/User:Phonybone/Python_Nodes
[2] http://projects.blender.org/scm/viewvc.php/trunk/blender/release/scripts/templates_py/custom_nodes.py?view=markup&root=bf-blender
[3] http://code.blender.org/index.php/2012/01/improving-node-group-interface-editing/
for now subtype is not defined, but once we start parsing the metadata we can set texture inputs as FILEPATH
also, it takes relative strings and convert to absolute for all strings (which is arguably a good solution, but
should work for now)
The structs stored in the anonymous void *default_value in bNodeSocket are now handled completely inside node_socket.c. All allocation/freeing/duplicating for this has been replaced by the appropriate calls to generic API functions (declared in NOD_socket.h).
This will make the default value handling more reliable for future node socket code. Group socket copying and value conversion has also been moved into the generic socket API file.
