UNPKG

@acransac/vtk.js

Version:

Visualization Toolkit for the Web

github.com/kitware/vtk-js

kitware/vtk-js

55 lines (35 loc) • 2.2 kB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
## Introduction The `vtkMatrixBuilder` class provides a system to create a mat4 transformation matrix. All functions return the MatrixBuilder Object instance, allowing transformations to be chained. Example: ``` let point = [2,5,12]; vtkMatrixBuilder.buildfromDegree().translate(1,0,2).rotateZ(45).apply(point); ``` ## Creating an instance The vtkMatrixBuilder class has two functions, `vtkMatrixBuilder.buildFromDegree()` and `vtkMatrixbuilder.buildFromRadian()`, predefining the angle format used for transformations and returning a MatrixBuilder instance. The matrix is initialized with the Identity Matrix. ## Transformation Functions ### `rotateFromDirections(originDirection, targetDirection)` Multiplies the current matrix with a transformation matrix created by normalizing both direction vectors and rotating around the axis of the crossProduct by the angle from the dotProduct of the two directions. ### `rotate(angle, axis)` Normalizes the axis of rotation then rotates the current matrix `angle` degrees/radians around the provided axis. ### `rotateX(angle)` Rotates `angle` degrees/radians around the X axis. ### `rotateY(angle)` Rotates `angle` degrees/radians around the Y axis. ### `rotateZ(angle)` Rotates `angle` degrees/radians around the Z axis. ### `translate(x, y, z)` Translates the matrix by x, y, z. ### `scale(sx, sy, sz)` Scales the matrix by sx, sy, sz. ### `identity()` Resets the MatrixBuilder to the Identity matrix. ### `setMatrix(mat4)` Copies the given `mat4` into the builder. Useful if you already have a transformation matrix and want to transform it further. Returns the instance for chaining. ## Using the MatrixBuilder result ### `apply(typedArray, offset = 0, nbIterations = -1)` Multiplies the array by the MatrixBuilder's internal matrix, in sets of 3. Updates the array in place. If specified, `offset` starts at a given position in the array, and `nbIterations` will determine the number of iterations (sets of 3) to loop through. Assumes the `typedArray` is an array of multiples of 3, unless specifically handling with offset and iterations. Returns the instance for chaining. ### `getMatrix()` Returns the internal `mat4` matrix.