setInfiniteMatrix function

void setInfiniteMatrix (Matrix4 infiniteMatrix, double fovYRadians, double aspectRatio, double zNear)

Constructs an OpenGL infinite projection matrix in infiniteMatrix. fovYRadians specifies the field of view angle, in radians, in the y direction. aspectRatio specifies the aspect ratio that determines the field of view in the x direction. The aspect ratio of x (width) to y (height). zNear specifies the distance from the viewer to the near plane (always positive).

Implementation 

void setInfiniteMatrix(Matrix4 infiniteMatrix, double fovYRadians,
    double aspectRatio, double zNear) {
  final double height = math.tan(fovYRadians * 0.5);
  final double width = height * aspectRatio;

  infiniteMatrix
    ..setZero()
    ..setEntry(0, 0, 1.0 / width)
    ..setEntry(1, 1, 1.0 / height)
    ..setEntry(2, 2, -1.0)
    ..setEntry(3, 2, -1.0)
    ..setEntry(2, 3, -2.0 * zNear);
}