Often you need to copy a spline to do an operation, but don't want
to manually copy over all of the settings. I've already forgotten to
do it once anyway. These functions copy a spline's "settings" into a
new spline, but not the data. I tried to avoid duplicating any copying
so this is easier to extend in the future.
Differential Revision: https://developer.blender.org/D11463
With this patch you will be able to add and remove attributes from curve
data inside of geometry nodes. The following is currently implemented:
* Adding attributes with any data type to splines or spline points.
* Support for working with multiple splines at the same time.
* Interaction with the three builtin point attributes.
* Resampling attributes in the resample node.
The following is not implemented in this patch:
* Joining attributes when joining splines with the join geometry node.
* Domain interpolation between spline and point domains.
* More efficient ways to call attribute operations once per spline.
Differential Revision: https://developer.blender.org/D11251
Since spline data is stored separately for each spline, the data often
needs to be flattened into a separate array. It's helpful to have the
necessarily-sequential part of that split off into a separate method.
I've found myself using functions like these in quite a few places.
Not allowing external direct access to the vector of splines in the
curve will help for things like reallocating custom data when a spline
is added or removed.
This commit exposes the first spline control point attributes. The
implementation incorporates the attributes into the virtual array
system, providing efficient methods to flatten the data into a
contiguous array and to apply changes from a flattened array. This
is only part of the eventual goal, which includes changes to run
attribute nodes separately for each spline to completely avoid copying.
So far `tilt` and `radius`, the two generic attributes common to
all spline types, are implemented. The more complex `position`
attribute is also added. It requires some special handling for Bezier
splines, where the control point handles need to be moved along with
the control points. To make that work I also added automatic handle
recalculation to the Bezier spline.
Differential Revision: https://developer.blender.org/D11187
Was giving a warning:
```
BKE_spline.hh:293:35: warning: 'interpolate_to_evaluated_points' overrides a
member function but is not marked 'override' [-Winconsistent-missing-override]
```
This node generates a naturally parametarized (even length edge) poly
spline version of every spline in the input. There are two modes,
"Count", and "Length". These are similar to the same options for the
line primitive node in end points mode.
I implemented this instead of a "Sample Points" node, because for this
operation it's trivial to keep the result as a curve, which is nice
since it increases flexibility, and because it can make instancing
simpler, i.e. using the transforms of each evaluated point rather than
requiring the construction of a "rotation" attribute.
Differential Revision: https://developer.blender.org/D11173
This patch adds initial curve support to geometry nodes. Currently
there is only one node available, the "Curve to Mesh" node, T87428.
However, the aim of the changes here is larger than just supporting
curve data in nodes-- it also uses the opportunity to add better spline
data structures, intended to replace the existing curve evaluation code.
The curve code in Blender is quite old, and it's generally regarded as
some of the messiest, hardest-to-understand code as well. The classes
in `BKE_spline.hh` aim to be faster, more extensible, and much more
easily understandable. Further explanation can be found in comments in
that file.
Initial builtin spline attributes are supported-- reading and writing
from the `cyclic` and `resolution` attributes works with any of the
attribute nodes. Also, only Z-up normal calculation is implemented
at the moment, and tilts do not apply yet.
**Limitations**
- For now, you must bring curves into the node tree with an "Object
Info" node. Changes to the curve modifier stack will come later.
- Converting to a mesh is necessary to visualize the curve data.
Further progress can be tracked in: T87245
Higher level design document: https://wiki.blender.org/wiki/Modules/Physics_Nodes/Projects/EverythingNodes/CurveNodes
Differential Revision: https://developer.blender.org/D11091
