The Swiss artist Pipilotti Rist is best known for a video in which she appears fairly dancing down the street smashing car windows with a large metal flower. She wears ruby shoes and a delirious smile. A passing policewoman salutes this riotous freedom, so you can assume there are politics at play, and that this is one of art's parallel universes. The scene glides dreamily along, mesmeric as an early Talking Heads video.
That was back in 1997, and if you want to know what Rist has been up to ever since then go to the Hayward Gallery. Thirty or so works fill that cavernous space with a hippy-dippy swirl of moving images, picturesque sculptures and swoony sounds. The show reaches back to the mid-80s, when the artist was in a folk-punk band and making short sharp works like "I'm Not the Girl Who Misses Much" – in which she appears bare-breasted like a Minoan goddess singing that Beatles line (the article piquantly adjusted from "a" to "the"); and forward to the present day and the big immersive installations of her late 40s.
In between, Rist's distinct aesthetic is played out over and again on a grand and small scale. This runs all the way from the voluptuous to the pretty and cute. And if that feels pointed – sunshine, flowers, juicy fruits, flawless nudes, the politics of pleasure – then at least it raises the question (or indeed the absence) of a point.
The show opens with a chandelier festooned with pristine white underwear: families of flimsies held up to the light, seen to be innocent after all. On the opposite wall is an immense collage of white objects – sponges, sieves, saucers, Tupperware – charming to look at and arranged as appealingly as the household goods in a John Lewis window; though I suppose it could also be a catalogue of domestic banality.
In a doll's-house model of a child's bedroom a dreamy planet is coming through the wall. If you sit on a nearby chair a pretty landscape is projected in your lap, and sunset on the lamp alongside. Can it all be so unresistingly charming?
Projections flicker in intimate corners. A camera runs its eye over a woman's naked contours and discovers twinkling jewels in all the apt hills and valleys. Peer into an open handbag and you spy a film of another nude woman swimming in warm water, which sexual conceit is repeated again, and again, between the lips of various shells.
The largest installation is a hanging garden of gauzy drapes on which are projected gamboling mountain goats, enormously enlarged blossoms, close-ups of mouths eating ripe tomatoes and any number of sunny uplands. On the floor are stuffed clothes on which you might lounge, tuning into the ambience as the airy-fairy frieze flutters over your body to the sound of tinkling cowbells. I was out of there before you could say windchimes.
The difficulty with all this come-together joyfulness is not that it lacks an adult dimension. Look closer and you will see penis, anus, vulva, dangling epiglottis. One work is devoted to sex in the head (a head, upon which sex is projected), another to menstrual blood. And what a beautiful colour it is – so rich, so lush! Rist's assertions are both bland and gradually coercive.
A dipping cable car, a gliding camera, a monologue about marital breakdown delivered from a Citroën slipping through a golden landscape: slow, rhythmic movement is her modus operandi in the videos of recent years. And in the dark fug of the Hayward this can be mesmerising or stultifying depending on your expectations of art (or the artist, whose work once had such pith and vigour).
The later the work, the tamer it gets; this is art for the crowd-hungry Kunsthalle. We are all meant to be in it together, lying about in mutual bodily warmth gazing at these images that go round and round like the windmills of our minds. Yet the analogies Rist sets up – dreams/films, minds/screens – do not come off because her videos, of late, are so frictionless and empty. What is happening in the viewer's head is almost bound to be more interesting than what is going on before her eyes.
The Welsh-born sculptor Barry Flanagan, who died two years ago at the age of 68, was so strongly associated with those outsize bronze hares that leap their way through public spaces across the world (funny bunnies as they were inevitably known) that it is quite surprising to find only one in this show, as if Tate Britain was hell-bent on avoiding the obvious.
But in concentrating on the years 1965-82 the curators are able to present the much greater range of his art: maverick, conceptual, ever inventive; attracted to rough and cheap materials and yet, in its playfulness, more obviously presaging the commercial bronzes than one could have expected.
Those materials were crucial – central. Flanagan's four sheets of neatly folded hessian, inspired by family blankets and now so venerable the dust makes one sneeze, were once considered as outrageous as Carl Andre's bricks during the notorious anti-Tate campaigns of 1976. He propped sticks in elegant ziggurats, transformed stones into figures with little more than an incised or chalked line, tore coloured paper into gleeful new flags to celebrate the events of 1968.
Early success came at St Martin's School of Art in his 20s. Flanagan would stitch irregular hessian bags, fill them with sand and wait to see how the substance would behave when contained. The resulting sculptures – irregular, tubular, bulging like thighs or nearly splitting their sides – are nameless but full of character: hapless, toppling, cheery, distended. You can see a good deal of art prefigured there, from Ernesto Neto's stuffed muslin biomorphs to Sarah Lucas's stuffed-stocking bunnies.
Over the years Flanagan found a lot of ways of making paintings without paint or brush. One of the best things here is a "painting" on the wall, drippily beautiful but in fact nothing more than a projection of golden light. Another is a great rivulet of rope, twisting and turning like a vast brushmark across the floor.
There are sheets of canvas propped against the wall with sticks, their swags holding topographies of darkness and light. There are canvases stitched with knots that resemble thick impasto; sculptures playing at being paintings, and vice versa. (There are plenty of gauzy drapes.)
Most comic of all is a great heap of stuffed sacks cosying up in a corner of the room, a beam of light falling upon them. It is as if one had opened a barn door and caught them in flagrante.
Strong scholarly emphasis is given here to Flanagan's interest in Alfred Jarry, but there is no need to linger over the documents. This art can thrive without knowledge of 'Pataphysics or Ubu Roi. The pieces hit, and sometimes they miss, but Flanagan just keeps at it, his joie de vivre as irrepressible as the characteristic urge to get out of the rut. Restless and exuberant, his zest was for discovering what could be done with humble stuff almost to the point where one could regret the eventual production line in monumental bronzes.
