This implements bundles and closures which are described in more detail in this
blog post: https://code.blender.org/2024/11/geometry-nodes-workshop-october-2024/
tl;dr:
* Bundles are containers that allow storing multiple socket values in a single
value. Each value in the bundle is identified by a name. Bundles can be
nested.
* Closures are functions that are created with the Closure Zone and can be
evaluated with the Evaluate Closure node.
To use the patch, the `Bundle and Closure Nodes` experimental feature has to be
enabled. This is necessary, because these features are not fully done yet and
still need iterations to improve the workflow before they can be officially
released. These iterations are easier to do in `main` than in a separate branch
though. That's because this patch is quite large and somewhat prone to merge
conflicts. Also other work we want to do, depends on this.
This adds the following new nodes:
* Combine Bundle: can pack multiple values into one.
* Separate Bundle: extracts values from a bundle.
* Closure Zone: outputs a closure zone for use in the `Evaluate Closure` node.
* Evaluate Closure: evaluates the passed in closure.
Things that will be added soon after this lands:
* Fields in bundles and closures. The way this is done changes with #134811, so
I rather implement this once both are in `main`.
* UI features for keeping sockets in sync (right now there are warnings only).
One bigger issue is the limited support for lazyness. For example, all inputs of
a Combine Bundle node will be evaluated, even if they are not all needed. The
same is true for all captured values of a closure. This is a deeper limitation
that needs to be resolved at some point. This will likely be done after an
initial version of this patch is done.
Pull Request: https://projects.blender.org/blender/blender/pulls/128340
Adds support for the "Menu" socket type in for-each-element zones. This
only includes field inputs and their matching per-element values, but
not outputting attributes of type Menu (Menu attributes are not
generally supported at this point).
A dedicated enum propagation function is added for the zone input node.
This isn't technically necessary: the first 2 inputs and outputs should
be ignored but are not menus anyway. However, this is clearer and
provides a place for future changes.
Pull Request: https://projects.blender.org/blender/blender/pulls/128106
`GVolumeGrid` and `VolumeGrid<T>` are basically pointer wrappers.
Assigning a nullptr is possible and allowed by code, but node socket
code doesn't currently check if a grid pointer is null before accessing
it.
Disallow null grid pointers in socket values. Asserts are added for this
purpose. The Points-to-SDF node checks the grid value before writing to
output.
Pull Request: https://projects.blender.org/blender/blender/pulls/122996
Implements the design from #116067.
The socket type is called "Matrix" but it is often referred to as "Transform"
when that's what it is semantically. The attribute type is "4x4 Matrix" since
that's a lower level choice. Currently matrix sockets are always passed
around internally as `float4x4`, but that can be optimized in the future
when smaller types would give the same behavior.
A new "Matrix" utilities category has the following set of initial nodes"
- **Combine Transform**
- **Separate Transform**
- **Multiply Matrices**
- **Transform Direction**
- **Transform Vector**
- **Invert Matrix**
- **Transpose Matrix**
The nodes and socket type are behind an experimental flag for now,
which will give us time to make sure it's the right set of initial nodes.
The viewer node overlay doesn't support matrices-- they aren't supported
for rendering in general. They also aren't supported in the modifier interface
currently. But they are supported in the spreadsheet, where the value is
displayed in a tooltip.
Pull Request: https://projects.blender.org/blender/blender/pulls/116166
This is the initial implementation for the volume grid sockets that has been
discussed during the November 2023 geometry nodes workshop.
It adds initial support for passing volume grids around in sockets. Furthermore,
it adds two new nodes. Both are initially hidden under the "New Volume Nodes"
experimental option until we have a few mode nodes.
* **Get Named Grid**: Gets or extracts a volume grid from a volume geometry
based on the grid's name.
* **Store Named Grid**: Puts a volume grid back into a volume with a name.
`SocketValueVariant` is extended to support grids besides single values and fields.
Next steps:
* Implement grid socket shape and inferencing (currently, they just look like
single values).
* Add implicit conversions between grid types.
* Implement nodes that operate on the grids (#116021).
* Improved spreadsheet and viewer support.
Links:
* https://devtalk.blender.org/t/volumes-in-geometry-nodes-proposal/31917
* https://devtalk.blender.org/t/2023-11-06-geometry-nodes-workshop-notes/32007#volumes-3
Co-authored-by: Jacques Lucke <jacques@blender.org>
Pull Request: https://projects.blender.org/blender/blender/pulls/115270
This refactors `SocketValueVariant` with the following goals in mind:
* Support type erasure so that not all users of `SocketValueVariant` have
to know about all the types sockets can have.
* Move towards supporting "rainbow sockets" which are sockets whoose
type is only known at run-time.
* Reduce complexity when dealing with socket values in general. Previously,
one had to use `SocketValueVariantCPPType` a lot to manage uninitialized
memory. This is better abstracted away now.
One related change that I had to do that I didn't see coming at first was that
I had to refactor `set_default_remaining_outputs` because now the default value
of a `SocketValueVariant` would not contain any value. Previously, it was
initialized the zero-value of the template parameter. Similarly, I had to change
how implicit conversions are created, because comparing the `CPPType` of linked
sockets was not enough anymore to determine if a conversion is necessary.
We could potentially use `SocketValueVariant` for the remaining socket types in the
future as well. Not entirely sure if that helps yet. `SocketValueVariant` can easily be
adapted to make that work though. That would also justify the name
"SocketValueVariant" better.
Pull Request: https://projects.blender.org/blender/blender/pulls/116231
