When nodes are loaded from a .blend file they can potentially have undefined types. This can happen if a type has been deprecated and removed, or if node types were defined in a python script that has not been loaded correctly. Previously all such nodes would automatically be removed from a node tree, assuming that their types were deprecated and no longer in use (more commonly caused by loading new nodes in an older Blender version). Due to the possibility of dynamic registration it is no longer feasible to simply delete such nodes.
Display and handling of node trees was simply disabled before this patch, so that a node tree where any node or socket type was undefined would not be displayed at all. To give more information and avoid problems caused by necessary checks for the typeinfo pointer, there is now a 'Undefined' fallback type for trees, nodes and sockets. These types are used as placeholders in case the real type is not registered and can provide useful visual feedback on undefined nodes.
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/
Two example files that crashed texture nodes.
- On delete texture nodes, it should free the exec cache (because this cache
stores the node pointer.
- On redo, nodes can exist can exist without typeinfo set. Exec (free) code
was not checking for that. Don't ask me why this happens... tex nodes are weird.
- Cycles materials now render in Blender Internal too, skipping the nodes.
Not very useful, but at least things then show up on renders and in
previews.
- Node editor: if wrong shader nodes are in a tree, they draw with thene
color RED ALERT headers now. (Switching render engine will show it).
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)
Storing this list in the node has the advantage of requiring far fewer calls to the potentially expensive internal_connect callback. This was called on every node redraw ...
Also it will allow Cycles to properly use the internal links for muted nodes, which ensures consistent behavior. The previous method was not applicable in Cycles because transient list return values are not supported well in the RNA and particularly the C++ API implementation.
Problem here is that muted nodes and reroute nodes are supposed to be removed from the execution node tree during the localize function. However, this is function is apparently only used during preview renders and must be considered a hack (is there anything that is not a hack in BI?)
Now the mute/reroute check happens in the node tree exec functions still used by BI and the legacy compositor and texture nodes. It uses the same internal_connect function from nodes to assign input stack indices directly to outputs (which also avoids overhead). Localize function also still does this. Cycles/Tile should also implement muting/reroute in their intermediate node layers by using this function, then it could be removed from localize too.
It is not a well-supported feature of the primary node systems (shader, compositor, texture) in Blender. If anybody wants to create a node system that has actual use for loops, they can do so much more elegantly with Python nodes, but it does not have to be a core node type in Blender. Removing this should ease node code maintenance a bit.
- movieclip unlink didn't clear node ID pointers from the scene (leaving dangling pointers).
- mask datablock unlink was clearning references from scene nodes twice.
The reason is that the per-node updates used for Reroute node type inheritance are not supposed to be looking at connected nodes, they are purely for "local" updates. For this sort of "global" update which requires depth-first search, the update function on the node tree level must be used instead.
1) For inserting into existing groups:
The 'Make Group from selected' (CTRL+g) operator shows a selection popup (like the object parenting operator), with options depending on the type of the active node (last selected):
* "New" -> regular operator, creates new group type with all selected nodes inside.
* "Insert" (only if active node is a group) -> adds all other selected nodes into the group.
Currently still prohibits groups inside groups in general, though would be technically possible as long as no actual recursion occurs (group containing itself).
2) For extracting from an existing group:
New 'Separate from group' operator (p), works similar to separating vertices/edges/faces from mesh. Two modes:
* "Copy" makes a copy of the nodes in the parent tree, but keeps the original group intact.
* "Move" removes selected nodes from the node group and adds them to the parent tree
By holding shift and "cutting" a node link a new reroute helper node can be inserted. This consists of a single socket that can be used to insert additional connection points into a link. This can be used to keep a connection point in the tree when deleting a node, or to control the path of long connections for layout cleanup.
For an detailed user-level description of new features see the following blogpost:
http://code.blender.org/index.php/2012/05/node-editing-tweaks/
TL;DR:
* Frame node gets more usable bounding-box behavior
* Node resizing has helpful mouse cursor indicators and works on all borders
* Node selection/active colors are themeable independently
* Customizable background colors for nodes (useful for frames visual
distinction).
