One of the enduring 20th-century images of mass folly is the shot - reproduced on many a jokey retro postcard - of 1950s cinema audiences, wearing cumbersome cardboard glasses as they gawp at some extravaganza in living, in-your-lap 3D: Bwana Devil! House of Wax! Cat Women of the Moon!
Such crowd scenes look to us now like the epitome of passive hickdom. How sheep-like could people be? But that's just the snobbery of historical hindsight. In reality, for all the tawdriness of much of the 1950s 3D cycle, contemporary audiences were enjoying nothing more witless than a dabble in the pleasures of trompe l'oeil illusion. Trompe l'oeil , far from entailing a passive viewer, is an active, critical process - it requires viewers to measure their 2D expectations against the semblance of three dimensions. It's the film equivalent of puzzling over an Escher print.
In fact, seen today, 1950s 3D doesn't look 3D at all -more like a set of 2D planes aligned in an imaginary 3D space, rather like a cardboard pop-up book. Take the forthcoming re-release of the 1953 movie Kiss Me Kate. Despite the Cole Porter songs, it's not a great musical - it is contrived and woodenly theatrical. But what's fascinating is that its theatricality goes together with a bizarre visual flatness. The film makes ample use of one of the great 3D cliches - with characters hurling gloves, dice, goblets directly at the camera - but it's the flatness, the cardboard cut-out aspect, that is really transfixing.
The opening sequence in Howard Keel's apartment is a bizarre construction of diagonals and receding surfaces. There are mirrors everywhere, fragmenting the space into as many flat planes as possible. The scene looks unnerving, almost sinister, and every inch like a stage set. It seems like the locale not for a musical but for a murder mystery. Later, when the characters take to the stage in an impressionistic mock-up of Shakespearean Padua, the two-dimensionality is even more pronounced: the set looks like a Broadway version of De Chirico.
Paradoxically, 3D cinema offers a rare chance to revel in the truly 2D. Films like Kiss Me Kate don't make things more lifelike; quite the contrary. We are in the habit of seeing people and objects on screen as if they were 3D anyway: we assume we are seeing flesh-and-blood actors rather than flat 2D shapes. Seeing a 1950s 3D film in all its awkward cut-out quality allows us to measure the difference between the cinematic illusion we habitually manufacture in our own minds and a different kind of illusion, with limitations that are all too obvious.
But 3D technology has come a long way since then. With 3D productions for the vast Imax screen, we still wear the comical glasses, but the critical distance has diminished. One of the most dazzling, most sense-engulfing spectacles I have ever seen - bigger, brasher, more kitsch than Fantasia, Gladiator, Independence Day, you name it - is the 3D Imax digital animation Cyberworld. A flashy portmanteau of computer-generated clips, Cyberworld displays a level of digital polish that makes Toy Story look homespun. A vast, futuristic space called the Galleria Animatica is the setting for various delights and horrors - sci-fi seascapes, futuristic big top extravaganzas, la Cirque du Soleil, a hideously ornate fantasia featuring the Pet Shop Boys, and (pause for breath and a welcome bit of primary-colour 2D clunkiness) the episode of The Simpsons in which Homer crosses into a 3D universe ("Man, this place looks expensive!").
Where 1950s 3D pelted us with flying cups now and then, the 21st- century variant goes much further. If crockery flew in Cyberworld, it would come in all-enveloping cyclones of intricately-traced willow-pattern china. No space is left unfilled, no surface without a fastidiously mapped texture.
It's not just in front of you but all around. Thanks to a huge screen that allows no peripheral vision outside itself, the aesthetic is one of total immersion, and the immersion is merciless, the bombardment non-stop. When you're not floating through galactic oceans, you have a million bubbles exploding in your face, a million clown-hatted bird-things with the face of Neil Tennant morphing in geometric formation.
The effect is oppressive - this seems to be a form of cinema that makes it almost impossible to react critically. And it may be no accident that Cyberworld's artists favour images of monumental architecture, like the cathedral-like vastness of the Galleria Animatica itself. There is, perhaps, an inherently totalitarian aesthetic to this form of cinema - it involves not imaginative involvement but knee-jerk submission. Perhaps bombastically inclined dictatorships in the coming century need not waste their resources on rallies or cumbersome monuments - state-of-the-art Pet Shop Boys videos may prove a much smarter investment.
• Kiss Me Kate is re-released on January 19. Cyberworld is screening at the BFI Imax, London SE1 (tel: 020-7902 1234).
