update method
dynamic
update()
Implementation
update() {
var mesh = children[0];
if (color != null) {
material.color.copy(color);
} else {
var colors = mesh.geometry!.getAttribute('color');
_color1.copy(light.color!);
_color2.copy(light.groundColor!);
for (var i = 0, l = colors.count; i < l; i++) {
var color = (i < (l / 2)) ? _color1 : _color2;
colors.setXYZ(i, color.r, color.g, color.b);
}
colors.needsUpdate = true;
}
mesh.lookAt(_vectorHemisphereLightHelper.setFromMatrixPosition(light.matrixWorld).negate());
}