| The design process is quite complex, designers need to have a variety of basic skills. For designers, the expression of their design ideas in the design process is a particularly important link, and their capabilities will have a direct impact on the transformation of design thinking and the expression of design results. The transformation of design thinking and the expression of design results are inseparable from the outcome of hand-painted. A good designer, not only have good ideas, but also have the ability to express their ideas through a certain forms of expression, because we know that if the design ideas need to be perceived, some specific carrier must be used to transform them, and the sketch can express the idea of the designer quickly and effectively. It is obvious that the importance of hand-painted is self-evident, hand-painted is a process from simple to complex. From the sketch hooking to the color training to the ideographic fast performance, Hand-painted can develop us earnest, heavy, and not impetuous attitude.With the development of technology, computer services come into our life, which penetrated into all walks of life, so the emergence of computer-aided design industry for design, modeling software also emerged. Computer modeling is more accurate and vivid than hand-painted. In recent years, various versions of computer modeling software emerge in endlessly, but their functions are mostly parametric modeling, the users need to entry the relevant values and have a strong sense of three-dimensional space. In the modeling process, the users need to input values to adjust the coordinates of the location, and modify the model parameters to achieve the desired effect. The process is complex and requires the user's high professional standards, which makes the computer interaction not perfect.Through the analysis on all the pros and cons of the sketches and the computer-aided design, we found that if we combine the two models—traditional pen and paper sketch design and computer aided design technology, take the advantages from them, we provide a form of computer-aided design, which is in the form of hand-painted with digital screen as the transmission media, designers can work out their creative ideas in such an environment similar to pen and paper sketching, so can the results of their ideas be directly transformed into the digital three-dimensional model, which have a great significance on the promotion of product innovation and the improvement of work efficiency. This is also a trend of computer-aided design, under current technology, software which is based on hand sketching to build a three-dimensional model have appeared, I believe that it will be more perfect in the near future. |