NEW YORK (AP) _ Joan Vass' ambitious collection for fall 1985 runs the gamut from sleepwear to evening gowns and includes men's and women's styles, while Jackie Rogers concentrates in her show on dress-up clothes for women.

Ms. Vass' big, fun collection included many spectacular bulky sweaters. Some were solid to emphasize the exquisite knitted patterns. Others came in hot combinations such as mustard, rust and violet or red and magenta. And some were nubby tweeds.

One exceptional number, called an ''iguana'' sweater, actually resembled the horny hide of that tropical lizard. The hem was a series of jagged points, the back a mass of knitted horns and the wool helmet had a zig-zag comb that in profile resembled the iguana's row of spines.

Ms. Vass' sense of humor pervaded the show, held Thursday at the Parsons Fashion Center on Seventh Avenue. Models actually smiled, interacted, and in one case, pantomined a breakup after the ivory taffeta wedding gown was shown.

Most of the sweaters, which are Ms. Vass' specialty, are no-nonsense and could be the linchpins of a winter wardrobe. Unisex standards, V-neck pullovers, cardigans, turtlenecks, and three-button polos, were shown in pretty solids such as mustard, navy, ivy green, red, taupe and ivory. Also nice were gray and taupe houndstooth and ochre and brown houndstooth shown as men's crewnecks.

Some were wild, magenta angora and pink tweed, for example, or turquoise angora with brown and tan tweed stripes. Yet even the wildest ones could be toned done with appropriate separates.

One series of sweater outfits was shown with knitted ''hangman's hats,'' a pulled-down watch cap with almond-shaped eye holes, like an executioner's mask. But they were not intended seriously. The program notes called the grouping ''a protest rally,'' and said the clothes were ''the best cover for warmth, action and anonymity.''

The joke fell flat as the gray and taupe tweed sweaters were not that exciting. One odd shape is the shirttail cardigan. As the name hints, the back piece hangs down like a shirttail for an uneven hem.

The fabric defined more than one piece. A black, gray and white nubby knit sweater dress was little more than plain pullover but the fabric made it very special. It was shown with red mittens and hat and printed knee socks and odd little plaid shoes.

Two coats, both shown in a variety of practical neutral colors, also were standouts, a hooded shepherd's coat in alpaca and a balmacaan, a loose overcoat with raglan sleeves named for the town in Scotland.

According to Ms. Vass, her clothes are ''not meant to go out of style and are being expanded to form a continuum. The clothes are meant to be enjoyed.''

While Jackie Rogers gave no statement of purpose, it clearly was to make the most of the female figure.

Wrapped, draped, shirred and twisted wool jersey forms the basis for Ms. Rogers' fall collection of suits, dresses and gowns. Flashes of charmeuse, satin and organza as in a scarf, rose, shawl or a pocket square in an otherwise sedate suit.

Her suits come in two basic varieties: short straight skirts with squared jackets and round collarless necklines; or skirts gently gathered at one hip with a nipped waist jacket with a deep V neckline.

Day suits in subdued patterns such as a tiny black and white check, charcoal pinstripe or a navy with red version were livened up with a bit of red or white charmeuse wrapped around the neck and trailed down the back.

Stretchy wool jersey is the ideal fabric for accentuating the body's curves, and Miss Rogers does it again and again. One hourglass number was a royal blue dress with a shirred, front zipper closure from hem to V-neckline.

Shirring details also occurred on side seams, on the forearms, at the shoulders, and even across the fanny.

The designer relied on solid colors including black, navy, charcoal, royal, fuschia and beige, to show off her interesting way of twisting fabric so that it forms lots of gentle folds.

One ecru jersey gown with a twisted tummy piece was worn under a big fuzzy wool coat with a huge circle collar in the same tone. The bodice was strapless except for a sewn-in scarf that wrapped once around the neck then dangled down the back.

Dramatic dolman sleeves, which taper from a wide armhole to a narrow wrist, were used extensively on dresses and jackets and emphasized the slim torsos with which they were paired.

For evening, Miss Rogers showed the same feminine styles, but in nighttime fabrics, such as silver and gold lame, pale blue metallic velour, black satin, silk crepe and velvet.

The pinched waist suit became eveningwear when shown in rich fabrics such as satin accented with a single rhinestone button.

A golden velour two-piece gown paired a simple skirt with a plunging V neck, dolman-sleeved blouse with gathered waist, a soft curved hem, rhinestone closure and matching head wrap.