Study On Automatic Judgement Technology Of AutoCAD Three-dimensional Graphics Based On Unit Test Mode

With the rapid development of the national economy, CAD technology is widely used in all walks of life in china,and becomes an tool for enterprise innovation.So the demand for CAD talents in the state and society is quite large .CAD teaching as a important way to bring up CAD talents has become the important elements of CAD engineering drawing teaching. As Computer Test gradually becomes an important form of the Engineering CAD examination, it's the most urgent question to be solved that timing-wasting, error-prone manual judging way is substituted by auto-judging of multitudinous standardized CAD test papers with different contents and same forms by computer. This paper has studied automatic judge technology for AutoCAD three-dimensional graphics in a unit test mode and therefore provides a scientific and reliable bases for three-dimensional CAD teaching, training and testing.On the bases of referring image recognition and comparative study for AutoCAD two-dimensional and three-dimensional graphics, this paper studied deeply the key technology of the automatic judging for AutoCAD three-dimensional graphics in a unit test mode. The main contents include: (1) Three-dimensional CAD test unit and its sample analysis;(2) Study of monitoring technology in the testing process;(3) Study of automatic acquisition of the graphics datas information;(4) Study of evaluating test graphics datas and the standard answer graphic data;(5) Study of location detection technology in the test graphics;(6) Study of automation and integration technology in evaluation process;(7) Pre-development for the automation evaluation system of three-dimensional CAD graphic. This paper adopted such programming tools as VB,Vlisp language used graphic format conversion technology and thetraversal search method to graphic data information It could achieve functions as follows: (1) Automatically open three-dimensional graphics in batch.(2) Automatic conversion of data format from DWG to SAT and DXF.(3) Traversal search to graphic data of SAT and DXF files.(4) Automatic acquistion of three-dimensional graphics data.(5) Automatic storage of graphic data in Access database. Final results turned out. It is feasible for us to develop automatic evaluation system of AutoCAD three-dimensional graphics basing on unit test mode in order to realize such funtions as automatic evaluation result display and so on. And the evaluation results can achieve the requirements of the manual judging which can provide a better objective basis for substituting manual judging which is time-wasting and error-prone. It also lay a strong foundation for realizing standardized tests of the three-dimensional CAD with networking, automatic and paperless, and its automatic evaluating system.