Matrix.Compute.Transformation.FollowPath
This node generates a 4 x 4 transformation matrix by following a 2D path.
The position input slot allows choosing the location on the shape's path in the range 0.0 to 1.0, where 0.0 refers to the beginning of the shape's path and 1.0 to the end of the path. By slowing increasing the position input from 0.0 to 1.0 over time, the transformation is following the shape's path over time.
If the rotate flag is not set, the generated transformation contains only positional change (translation). If the rotate flag is set, the generated transformation contains translation and rotation.
The 2D path can be defined via the path data text input slot. Each command in the path data consist of a command character followed by several numeric parameter values:
| Command character | Number of numeric values | Example | Example semantic |
M | 2 | M 30 40 | Move to absolute position $x=30$, $y=40$ |
m | 2 | m 10 20 | Move to relative position $x=\tilde{x}+20$, $y=\tilde{y}+10$, where $\tilde{x}$ and $\tilde{y}$ define the position after execution of the previous command |
L | 2 | L 50 60 | Line to absolute position $x=50$, $y=60$ |
l | 2 | l 20 10 | Line to relative position $x=\tilde{x}+20$, $y=\tilde{y}+10$ |
H | 1 | H 50 | Horizontal line to absolute $x$-position $x=50$, $y=\tilde{y}$ |
h | 1 | h 20 | Horizontal line to relative $x$-position $x=\tilde{x}+20$, $y=\tilde{y}$ |
V | 1 | V 10 | Vertical line to absolute $y$-position $x=\tilde{x}$, $y=10$ |
v | 1 | v 10 | Vertical line to relative $y$-position $x=\tilde{x}$, $y=\tilde{y}+10$ |
C | 6 | C 10 20 30 40 50 60 | Cubic Bézier curve to absolute position $x=50$, $y=60$, where $x_1=10$, $y_1=20$ and $x_2=30$, $y_2=40$ define the absolute positions of the curve's control points |
c | 6 | c 10 20 30 40 50 60 | Cubic Bézier curve to relative position $x=\tilde{x}+50$, $y=\tilde{y}+60$, where $x_1=\tilde{x}+10$, $y_1=\tilde{y}+20$ and $x_2=\tilde{x}+30$, $y_2=\tilde{y}+40$ define the positions of the curve's control points |
S | 4 | C 30 40 50 60 | Cubic Bézier curve to absolute position $x=50$, $y=60$, where $x_1=2\tilde{x}-\tilde{x}_2$, $y_1=2\tilde{y}-\tilde{y}_2$ and $x_2=30$, $y_2=40$ define the positions of the curve's control points |
s | 4 | c 30 40 50 60 | Cubic Bézier curve to relative position $x=\tilde{x}+50$, $y=\tilde{y}+60$, where $x_1=2\tilde{x}-\tilde{x}_2$, $y_1=2\tilde{y}-\tilde{y}_2$ and $x_2=\tilde{x}+30$, $y_2=\tilde{y}+40$ define the positions of the curve's control points |
Q | 4 | Q 10 20 50 60 | Quadratic Bézier curve to absolute position $x=50$, $y=60$, where $x_1=10$, $y_1=20$ define the absolute position of the curve's control point |
q | 4 | c 10 20 50 60 | Quadratic Bézier curve to relative position $x=\tilde{x}+50$, $y=\tilde{y}+60$, where $x_1=\tilde{x}+10$, $y_1=\tilde{y}+20$ define the position of the curve's control point |
T | 2 | T 50 60 | Quadratic Bézier curve to absolute position $x=50$, $y=60$, where $x_1=2\tilde{x}-\tilde{x}_1$, $y_1=2\tilde{y}-\tilde{y}_1$ define the position of the curve's control point |
t | 2 | t 50 60 | Quadratic Bézier curve to relative position $x=\tilde{x}+50$, $y=\tilde{y}+60$, where $x_1=2\tilde{x}-\tilde{x}_1$, $y_1=2\tilde{y}-\tilde{y}_1$ define the position of the curve's control point |
Z | 0 | Z | closes the current path |
z | 0 | z | closes the current path |
Detailed explanation of the SVG path data format can be found in the SVG specification. The elliptical arc commands "A" and "a" are currently not fully supported.