Xu, who plays the alien, has worked on six films with Ning, including the runaway hit, Dying to Survive, which Ning produced and Wen Muye directed.
The new film also stars American actors Matthew Morrison and Tom Pelphrey. Oscar winner Joel Hynek is one of the visual-effects directors.
"I don't speak English," Ning says.
"So, it's a pity we had communication difficulties because of the language barrier."
Ning says the workload that came with using so many digital effects was challenging, since his previous films were mostly shot on real-life sets.
Xu says he had to shoot a lot of facial expressions that were used to generate the green creature's.
During the promotional event in Beijing on Jan 17, Ning also released a photo of a giant teardrop-shaped spaceship, inspired by a mysterious facility depicted in Liu's celebrated novel, The Three-Body Problem.
