SelectPointsWithSplines

SelectPointsWithSplines lets you to draw precise splines on a model, remove and rename them. It also allows loading and saving splines to a file. The output of the node are a named points on the geometry triangles, which are obtained from the drawn splines that are sampled to points using sampling parameters.

You can merge two sets of named points using a MergePoints node.

Two sets of named points can be combined into PointCorrespondences using a PointsToPointPairs node.

Editor

SelectPointsWithSplines node has a visual editor that allows adding, removing, editing, and renaming splines.

In idle state:

LMB	on geometry to start drawing a new spline
ALT + LMB	on existing spline to start drawing a new spline
SHIFT + LMB	on spline to select it
LMB	on spline and drag to edit
CTRL + LMB	to delete spline point
D	to switch between drawing splines and showing result points modes

When drawing a spline:

LMB	on geometry to add point to spline
LMB	on spline and drag to edit
CTRL + LMB	to delete spline point
SHIFT + LMB	on geometry to add shortest path to spline
RMB / ENTER	to finish spline
LMB outside geometry	to finish spline
ESC	to cancel spline drawing

Splines positions are stored as set of control points relative to a mesh triangles in which the control points are located so the same splines is suitable for different models with the same topology.

Tip

If model has topological or X/Y/Z symmetry you can use Symmetry parameter to draw or edit symmetrical splines simultaneously.

Inputs

Geometry: Geometry An input geometry

Output

NamedPointsOnTriangle Sampled points on geometry triangles from drawn splines

Parameters

Snap to Vertices:

if set, when drawing or changing spline control points they will be placed at the nearest vertex of the geometry

Symmetry:

No Symmetry: draw and edit one spline at a time
Topological: draw and edit two splines by topological symmetry at a time
X: draw and edit two splines by X-axis symmetry at a time
Y: draw and edit two splines by Y-axis symmetry at a time
Z: draw and edit two splines by Z-axis symmetry at a time

Mirror:

creates a symmetric spline for the current selection if the geometry has topological symmetry

Reverse:

reverses the order of control points of the selected spline

Delete:

deletes the selected spline

Resample Control Points:

resamples the control points of the selected spline

Point Sampling Mode:

Fixed Number per Spline: uses Num Points per Spline parameter and samples result points per spline
Fixed Number per Segment: uses Num Points per Segment parameter and samples result points per spline segment

Num Points per Spline:

defines a number of resulted sampled points per spline, if Fixed Number per Segment is selected this parameter will be ignored

Num Points per Segment:

defines a number of resulted sampled points per spline segment, if Fixed Number per Spline is selected this parameter will be ignored

Show:

Splines: enables editing splines mode
Result Points: enables showing resulted sampled points mode

Show Labels:

if set, splines and resulted sampled points names are displayed in the visual editor

Spline Base Name:

a base name for a newly created spline

Spline Padding:

defines a minimal number of digits that will be used in the name of a newly created spline

Spline-Point Separator:

a separator that will be placed between spline name and point index in a resulted sampled points

Auto Point Padding:

if set, automatically computes optimal Point Padding per spline

Point Padding:

defines a minimal number of digits that will be used in the names of a resulted sampled points, if Auto Point Padding is set this parameter will be ignored

Splines:

a widget that allows you to see all the splines you have drawn and select them

Rename All Splines:

renames all the splines according to specified base name and padding.

Delete All Splines:

deletes all the splines

Rename:

renames the selected spline

Import:

loads splines control points from a file

Export:

saves splines control points into a file

File Formats

Splines can be imported/exported in the following JSON formats:

Point On Triangle

The control points of a splines are represented in the following JSON format:

[ [0, 0.3, 0.5], [1, 0.0, 1.0], [2 0.5, 0.2] ]

This line stores three control points of one spline. Each point is represented with 3 numbers:

index of the triangle containing the point
the first barycentric coordinate of the point inside the triangle
the second barycentric coordinate of the point inside the triangle

Tip

If a model contains polygons with more than 3 vertices Wrap implicitly stores a triangulated version of the model. Wrap uses naive fan triangulation with the fan origin at the first vertex of the polygon.

Tip

Barycentric coordinates is a way to encode point position inside a triangle with two numbers U and V. If a triangle has 3 vertices with 3D coordinates A, B and C, barycentric coordinates U and V defines a point in 3D which position is calculated like:

P = A * U + B * V + C * (1 - U - V)

3D-Point

This JSON format stores control points of a splines as coordinates in 3D space.

[ {"x":-4.0,"y":-2.0,"z":-1.0}, {"x":2.0,"y":1.2,"z":5.0}, {"x":2.0,"y":1.7,"z":0.5} ]

This line stores three control points of one spline. Each point is represented with 3 numbers:

X coordinate of the point
Y coordinate of the point
Z coordinate of the point