sub method
Subtract arg
from this.
Implementation
void sub(Vector3 arg) {
final argStorage = arg._v3storage;
_v3storage[0] = _v3storage[0] - argStorage[0];
_v3storage[1] = _v3storage[1] - argStorage[1];
_v3storage[2] = _v3storage[2] - argStorage[2];
}