Computer Graphics on Clothing Design Jimmy K.C. Lam The Hong Kong Polytechnic University Ref: The Impact of Computer Graphics on Clothing Design by Clive Walter, Marks and Sencer, U.K. by Clive Walter, Marks and Sencer, U.K.

Agenda n Introduction nCustomer Requirements on Garment n Historical Development on CAD in textile/garment n Modern CAD Garment Design Process n Advantages on Computer Graphics n Problems and Technical Challenges n Reference

Introduction Customer Requirements n What is it that attracts a customer to a garment in a store? n Initial impact will be colour and the design on the fabric, be it the stripe on a shirt, the print on a blouse, the lace on a slip. n It gives a visual impression, like or dislike. n Other factors are style, fabric quality, hand feels and price.

Introduction Use of CAD for visual impression n CAD has the ability to simulate these visual impressions. n But how CAD is being used? What changes are occurring? How will CAD develop? n The answers will emerge from how a garment is developed from initial design to its planned production.

CAD Historical Development Fabric Design (1) n Earliest application of CAD in fabric production was to replace chains and steels by replays, actuators or electro-mechanical devices. n In knitting, the electronic signal is to select and control the up/down movement of needles. n In weaving, the electronic signal is to control the up/down movement of warp threads. n On CAD systems, the required design can be simulated on a grid on a monitor. n Each square on the grid is given a colour corresponding to a knitted loop or woven thread.

CAD in fabric design (2) n Computers are able to give a visual image of the knitted jacquard or a striped or checked fabric. n Both colour and sequence are easily changed as the design process is refined. n Once completed, the electronic information is transferred to control the mechanism of the production machines

CAD Historical Development Clothing Design (1) n CAD in clothing are applied in three areas, namely 1) cutting/grading; 2) planning and 3) pattern modification. n In cutting, the shapes of cardboard pieces are given by X and Y co-ordinates by digitiser and entered into computer. n Grading or how each pattern shape changes to allow different sizes (says small, medium or large) is automatically achieved.

CAD Historical Development Clothing Design (2) n Planning is how the patterns should be nested in a lay plan to ensure maximum usage of fabric. n Pattern pieces are displayed in minature, can be manipulated, rotated and fitted together in relation to fabric width. n The finished lay plan is passed to the cutter for cutting operation. n Pattern modification systems have been developed which enable basic pattern shapes to be altered for different style and construction features. n Computer technology is used in the whole process from pattern design to the control of the cutting machine.

Modern CAD Garment Design Process (1) n Historical CAD processes are focus on production, e.g eliminate manual cutting by computer cutter, selecting needles up/down movement by electronic signal. n Modern CAD design process, however, is focus on customer and market requirements and the design process is grouped into FOUR stages:- n 1) Design Initiation Stage – in which the market place customer’s perceived needs are defined in terms of colour, style and fabric design.

Modern CAD Garment Design Process (2) n 2) Design concept stage –When many design options are explored and result in design offers which satisfy the defined criteria of customer needs n 3) Design making process –Where design offers are considered, ranges are developed and decisions to purchase are made. n 4) Technical design stage –Where the design offer is refined to precisely satisfy the fit, construction, garment performance and production requirements

CAD creates visual images n Computer colour graphic systems provide a powerful tools for both the retailer and garment designer especially for the first two stages (design initiation and design concept stages). n They are able to determine colour, simulate fabrics both printed and woven, simulate components such as lace and embroidery and map these on styles to give a realistic representation of drape. n They create a visual image of garment, its colour, fabric design and shape, the attributes that initially attract a customer when they enter a store.

Advantages on Computer Graphics n Better communication –Picture is worth thousand words. n Greater responsiveness –Decisions on garment can be made closer to launch date n More design offer –Designer is able to explore quickly, inexpensively and thoroughly the design options n Production innovation n Widening the role of garment design –By responding directly to the market need, garment designers are becoming more involved in fabric and component design.

Technical Challenges n Remote communication –Electronic communication of pictures of high resolution with true colour at high speed and affordable cost, between garment designer and retailer, between garment designer and fabric designer and production sources. n Connectivity –Transfer of structured design information throughout the whole product design and development chain n Colour communication –Most important technical aspect. A consistent true colour is, in which the colour seen on different monitors and printers, responding to the same colour co-ordinates, is the same both within a system and between systems

Questions n What are the traditional roles of CAD process in textile and garment? n What are the new roles of CAD process in garment design? n What are the limitations of CAD process in textile and garment design?