I should not speak ill of Yann Martel's humongously popular 2001 novel Life of Pi, because I couldn't bring myself to finish it. Got a third of the way through, decided that one day, I was going to die, and on my deathbed, I didn't want to find myself reflecting on the time I wasted wallowing in Martel's infantile prose and cloying symbolism, and what was shaping up to be an awfully twee, New Agey message about choosing to have faith.

But even if I lack the intellectual right to speak thus of its source material, I've got to say that the Ang Lee-directed movie version of Life of Pi just goes to prove one of this blog's most cherished truths: style matters. Because the film, an unnervingly close adaptation as far as I made it through the book (and I am assured it remains so), has just exactly that twee message, and precisely that cloying symbolism, but in place of Martel's barely-literate writing, it has the craftsmanship of an inconsistently wonderful filmmaker doing some of his very best work, and somehow, the rest of it doesn't seem to matter much. Even the absurdly dysfunctional framework story which exists solely to harangue us and make dully explicit themes that the rest of the film has already made pretty damn clear, and which has an unerring tendency to jam the brakes on the narrative momentum, not simply by preventing the movie from getting started at the beginning, but poking up numerous times in the middle, and always in the most clumsy, messy way; even this unabashedly film-breaking frame manages to only do the movie a little bit of damage.

Because this is a visual medium, and the way a movie tells its story matters just as much as the story it tells. I came into Life of Pi looking for a fight, and I was chastened and had my own philosophy thrown right back at me: it is the image and not the word that drives cinema. And all my thanks to Lee for that reminder.

Life of Pi, ultimately, is about a young Indian boy named Pi, trapped on a lifeboat in the middle of the Pacific Ocean with a Bengal tiger named Richard Parker. Pi is played by non-actor Suraj Sharma, and given that the role requires virtually nothing at all besides physically existing, it cannot be said that he fails the movie, though on the basis of anything he does here, it also cannot be said that we'll be deprived of a great new talent if he decides not to pursue this new career path. Richard Parker is played by a CGI effect that represents as colossal a step forward in that artform as Gollum did in The Two Towers ten years ago this season; everything about his movements and weight, the way his fur moves in winder and water, the sense of stored-up energy when he's still; it's not just a great piece of effects work, it's a great piece of animation (and there are too many examples of the former without the latter), a totally convincing animal with presence and astonishing, addictive real-ness. The only part that ever goes wrong is that sometimes his eyes seem glassy and "float" above his face; and that only happens in close-ups; only in some close-ups. Outside of that, the cat is a titanic achievement of CGI realism.

Realism occupies a funny place in Life of Pi: the film relies to an inordinate and dangerous degree on our responding to Richard Parker entirely as if he were a complete real tiger, for example, and while I suppose that another tiger would be able to tell, just like even the best CGI human ever made still makes a real-world audience member's eyes water a little bit, for my needs the animal completely passes muster. But he's really just one CGI element among many; the film traffics in the abstractly gorgeous and the fantastical, while the film's stated message is "these things are impossible but also completely true", so in order to make that paradox land at all, it becomes absolutely vital to make things that aren't there look in every minute detail like they are. The visuals of Life of Pi focus with single-minded devotion on creating shots of intense beauty and poetry that are also completely plausible and photorealistic (and it's for this reason, too, that the much fussed-over 3-D is so important to the film: it adds dimension and physicality, further insisting on the "realness" of it all); and while this doesn't pay off in every single instance, the movie's best moments are as good as anything has been all year: a shot of a whale congealing from the murk of the sea's depths at night, or a kaleidoscopic image of dead fish in a pool of acid, or the matter of the shipwreck that puts Pi and Richard Parker on that lifeboat in the first place are all candidates for Goddamn Loveliest Thing of 2012.

What's frustrating is that Lee is doing all sorts of cinematic magic to bring to life in the most vivid way possible a script that kind of sucks; even leaving the matter of theme aside (which I do more to be politic than because I want to), it's a messy drama, rattling around erratically until it finally gets to the shipwreck that puts Pi in the water (and kicks off the cavalcade of glorious imagery), with a lengthy sequence that introduces us to Pi without ever actually characterising him; how much is the fault of Sharma's blank performance, and how much is the fault of David Magee's screenplay, and how much is the fault of Martel's model that Magee so helplessly follows, is difficult to say and immaterial. Regardless of blame, the point remains that Pi is a figure to whom things happen more than he is a personality whom we get to know well, despite the remarkable amount of time we spend listening to him speak, either as a young man or as an adult (played by the profoundly overqualified Irrfan Khan) in the tremendously annoying frame narrative, recalling his story to a dazzled writer (Rafe Spall, who isn't important enough to feel overqualified, and yet he does), a frame that further has the disadvantage of sprinkling a layer of Orientalism dust over the whole affair. Your mileage may vary, and all; what struck me about the film most of all, when I wasn't goggle-eyed at the visuals, was how resolutely unmoving all of it was; the whole thing was giddy filmmaking without any sort of human element. Yes, a young man trapped on a small boat with a hungry tiger is interesting; but not this boy, necessarily. And we spend far too much time on either side of the ocean getting to not-know him for me to regard this as anything but a fitfully brilliant, intermittent masterpiece.