Because animation appears headed toward permanent 3-D status, the independently produced "Battle for Terra" arrives at a propitious moment. This spry film demonstrates that 3-D need not strip away any charm, beauty or intelligence in favor of trick shots. The CG-animated sci-fi film, a first feature from shorts filmmaker Aristomenis Tsirbas, certainly delivers plenty of action. But everything evolves from the basic story as its characters struggle for survival on a distant planet.

There also is considerable dimension in the moral issues in what the filmmakers call a "reverse inspiration" by H.G. Wells' "The War of the Worlds." This time, the alien invaders are humans. Consequently, the themes and issues might fly over the heads of some youngsters. "Battle for Terra" definitely will play to a more select audience than that for DreamWorks' 3-D "Monsters vs. Aliens."

Originally shot in 2-D, "Terra," as it was then called, played the festival circuit from late 2007 through last year to considerable acclaim. However, Tsirbas and his producers had the foresight to employ a second camera with stereo properties. So after its festival playdates, the decision was made to go ahead with 3-D for theatrical release.

The result is a third dimension that helps establish an alien planet with free-floating inhabitants and a rainbow's worth of pleasing, soft, vibrant colors. Then comes an invasion. By watching these humans probe and then invade a planet from its inhabitants' point of view, the story, conceived by the director and written by Evan Spiliotopoulos, generates a shock of chagrined recognition along with divided loyalties. Do we root against the warlike humans and for the peace-loving Terrians?

The focal point of the action rests in an unlikely relationship between a feisty young Terrian and a macho human pilot. Terra's creatures live in harmony with an unusual nature that seemingly defies gravity. Unlike human society, conflict and competition are absent. Indeed, when the humans' bedraggled mother ship and its small spacecraft first appear, the Terrians mistake them for gods.

When hostile action ensues and young Mala (Evan Rachel Wood) sees her father captured by a spacecraft, she is determined to fight back. She lures an enemy pilot into a trap. When his craft is damaged and he is injured, she rescues the pilot, Jim (Luke Wilson). With the help of Jim's robotic companion, Giddy (David Cross) — who looks like a second cousin of WALL-E — Mala creates an oxygen environment that saves Jim's life.

Alas, the more hawkish elements of the human arc plot the invasion of the planet and destruction of its inhabitants. A sort of Us vs. Them with no possible alternative philosophy, in other words.

The Terrians, who mothballed their weapons and spacecraft several generations before, pull them out of cold storage as war ensues. But through all the battles in the skies, the Mala-Jim friendship, which is given only the slightest romantic overtones, tries to pull the course of events away from mutual total destruction.

A well-known cast of voice actors has been assembled, but the best thing that can be said is that you don't think of those actors when you hear the voices. Everyone is genuinely playing a character. The animation is splendid on what must have been — because this is not a studio film — a modest budget. And for all the plot points and characters, things conclude in a brisk 80 minutes. (partialdiff)