Goals of this refactor:
* Simplify creating virtual arrays.
* Simplify passing virtual arrays around.
* Simplify converting between typed and generic virtual arrays.
* Reduce memory allocations.
As a quick reminder, a virtual arrays is a data structure that behaves like an
array (i.e. it can be accessed using an index). However, it may not actually
be stored as array internally. The two most important implementations
of virtual arrays are those that correspond to an actual plain array and those
that have the same value for every index. However, many more
implementations exist for various reasons (interfacing with legacy attributes,
unified iterator over all points in multiple splines, ...).
With this refactor the core types (`VArray`, `GVArray`, `VMutableArray` and
`GVMutableArray`) can be used like "normal values". They typically live
on the stack. Before, they were usually inside a `std::unique_ptr`. This makes
passing them around much easier. Creation of new virtual arrays is also
much simpler now due to some constructors. Memory allocations are
reduced by making use of small object optimization inside the core types.
Previously, `VArray` was a class with virtual methods that had to be overridden
to change the behavior of a the virtual array. Now,`VArray` has a fixed size
and has no virtual methods. Instead it contains a `VArrayImpl` that is
similar to the old `VArray`. `VArrayImpl` should rarely ever be used directly,
unless a new virtual array implementation is added.
To support the small object optimization for many `VArrayImpl` classes,
a new `blender::Any` type is added. It is similar to `std::any` with two
additional features. It has an adjustable inline buffer size and alignment.
The inline buffer size of `std::any` can't be relied on and is usually too
small for our use case here. Furthermore, `blender::Any` can store
additional user-defined type information without increasing the
stack size.
Differential Revision: https://developer.blender.org/D12986
This patch includes an updated version of the raycast node that uses
fields instead of attributes for inputs instead of outputs. This makes
the node's UI much clearer. It should be faster too, since the
evaluation system for fields provides multi-threading.
The source position replaces the input geometry (since this node is
evaluated in the context of a geometry like the other field nodes).
Thanks to @guitargeek for an initial version of this patch.
Differential Revision: https://developer.blender.org/D12638
This commit adds an updated version of the old attribute transfer node.
It works like a function node, so it works in the context of a
geometry, with a simple data output.
The "Nearest" mode finds the nearest element of the specified domain on
the target geometry and copies the value directly from the target input.
The "Nearest Face Interpolated" finds the nearest point on anywhere on
the surface of the target mesh and linearly interpolates the value on
the target from the face's corners.
The node also has a new "Index" mode, which can pick data from specific
indices on the target geometry. The implicit default is to do a simple
copy from the target geometry, but any indices could be used. It is also
possible to use a single value for the index to to retrieve a single
value from an attribute at a certain index.
Differential Revision: https://developer.blender.org/D12785
Retrieving a mesh's looptris now take's a const mesh after
rB5f8969bb4b4, which removes the need for this function.
Since it's only two lines, avoiding the use of a separate function
in this case is simpler.
The //Raycast// node intersects rays from one geometry onto another.
It computes hit points on the target mesh and returns normals, distances
and any surface attribute specified by the user.
A ray starts on each point of the input //Geometry//. Rays continue
in the //Ray Direction// until they either hit the //Target Geometry//
or reach the //Ray Length// limit. If the target is hit, the value of the
//Is Hit// attribute in the output mesh will be true. //Hit Position//,
//Hit Normal//, //Hit Distance// and //Hit Index// are the properties of the
target mesh at the intersection point. In addition, a //Target Attribute//
can be specified that is interpolated at the hit point and the result
stored in //Hit Attribute//.
Docs: D11620
Reviewed By: HooglyBoogly
Differential Revision: https://developer.blender.org/D11619
