In this work, a 3D computer aided designing (cAD) system is developed for solid modeling and visual simulation of warp knitted structures on Silicon Graphics workstations. In the first part, a three-dimensional cylindrical and uniform solid yam model is developed, such that its central axis is a space curve, using non-uniform rational B-spline (NURBs) surfaces to achieve a true 3D solid representation of warp knit loops and structures. This yam model is then used to create single warp knit loops and fabrics. The necessary data for empirical loop models are obtained from experimental work. This paper describes the methodology and mathematics used to create the yam and loop models. Some examples of warp knit fabrics are generated on a computer using the empirical loop models, and these images are compared with real warp knit fabric pictures for visual evaluation.