Make the virtual functions protected and simpler, so that the logic is
better contained in the base class's implementation. Also introduce a
`copy_without_attributes` method to be used for realizing instances.
`src` and `dst` are perfectly clear, and avoid repeating unecessary
characters when writing the variables many times, allowing more space
for everything else.
This namespace groups threading related functions/classes. This avoids
adding more threading related stuff to the blender namespace. Also it
makes naming a bit easier, e.g. the c++ version of BLI_task_isolate could
become blender::threading::isolate_task or something similar.
Differential Revision: https://developer.blender.org/D11624
There is no particular reason these two functions shouldn't be used
outside of the bezier spline implementation since they don't do anything
particularly controversial.
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
The code incorrectly used the size of the second to last segment rather
than the last segment's size. That was a problem when the last segment
is a vector segment but the second to last isn't.
I also used the opportunity to slightly refactor the control point
offsets cache, making it one longer so it also contains information
about the size of the last segment, simplifying other code.
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
We need to always add a single point to the last cyclic segment that
completes the loop, because that includes the starting point of the
evaluated edge. The existing code forgot about that point.
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
While the method of interpolating based on the curve length at each
evaluated point may be useful in some situations, for now it's best to
be consistent with the existing methods in Blender, so this commit adds
a simple linear-based-on-resolution sampling method to bezier splines.
The special case for the interpolation to the last point was being used
for every point in the last segment, because of the rounding. Instead,
make the function slightly more complicated to properly handle the
correct interolation in the cyclic and non-cyclic cases.
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
