vArrayParametricCurve
Generate points from X(t), Y(t) and Z(t) expressions evaluated over a range of t.
vArrayParametricCurve has no input and outputs an array of XYZ points. Each of the three coordinates is given by a text expression in the variable t, which runs from T Min to T Max.
Parameters
| Parameter | Type | Default | Description |
|---|---|---|---|
| X(t) | Text | — | Expression for X in the variable t. Default cos(t). |
| Y(t) | Text | — | Expression for Y in the variable t. Default sin(t). |
| Z(t) | Text | — | Expression for Z in the variable t. Default 0. |
| T Min | Float | 0 | Value of t for the first sample. Default 0. |
| T Max | Float | 2 * math.pi | Value of t for the last sample. Default 2 * pi. |
+2 more parameters
| Parameter | Type | Default | Description |
|---|---|---|---|
| Sample Count | Integer | 360 | Number of samples. Clamped to 8 or more, default 360. |
| Scale | Float | 1 | Multiplier applied to X, Y and Z of every point. Minimum 0.001, default 1. |
Read the full description
The node evaluates the three expressions for Sample Count values of t, spaced evenly from T Min to T Max with both ends included. Each result is multiplied by Scale and written as a point. With the defaults (X(t) = cos(t), Y(t) = sin(t), Z(t) = 0, T Min 0, T Max 2 * pi, 360 samples, Scale 1) the output is a circle of radius 1.
The expressions use Lua syntax with t as the variable. The available names are abs, acos, asin, atan, ceil, cos, deg, exp, floor, log, max, min, pi, pow, rad, sin, sqrt and tan. The node lists examples such as a helix (cos(t), sin(t), t / (2 * pi)), a trefoil knot (sin(t) + 2 * sin(2 * t), cos(t) - 2 * cos(2 * t), -sin(3 * t)) and a torus knot ((2 + cos(3 * t)) * cos(2 * t), (2 + cos(3 * t)) * sin(2 * t), sin(3 * t)).
All three expressions must be filled in. If one is empty, cannot be compiled, or uses one of the blocked words os, io, debug, package, require, dofile, loadfile, collectgarbage, getfenv or setfenv, the output is empty. If an expression gives a value that is not a finite number for some t, that sample is skipped, so the output can hold fewer points than Sample Count.
Sample Count is clamped to 8 or more. Use the constant 0 for an unused axis.
Example Connections
- Draw the curve
- Offset the curve before drawing
vArrayParametricCurve.Output -> vArrayCameraProjection.ArrayA
vArrayCameraProjection.Output -> vArrayShapeRender.ArrayPoint
Background.Output -> vArrayShapeRender.Input
vArrayParametricCurve.Output -> vArrayTranslate.ArrayA
vArrayTranslate.Output -> vArrayCameraProjection.ArrayA