*Dr.*** Sukhanov**

*Institute for Advanced Science in Arad *

Making of Dynamic 3D Ideas Through Computer Graphics

It is believed that a highly developed dynamic 3-dimensional idea or imagination is necessary for realization of (3-dimensional) space simulation. (Dynamic idea is taken to mean that one can imagine a compound 3-dimensional object as consisting of several simple constituents or, conversely, design a compound 3-dimensional system of several simple elements). This is true. It is also believed that one can develop such ideas only through a prolonged studying of 3-dimensional graphics (descriptive geometry, machine drawing, etc.).

But experience proves that modern systems of 3-dimensional simulation (Autocad, Mechanical Desktop, Architectural, Compass, etc.) make possible solution of reverse problems, namely to develop 3-dimensional ideas in students by giving them certain knowledge in the field of conventional mechanical graphics ( coordinate systems, projection methods, arrangement of images, perspective geometry, dimensions, etc.).

Making of 3-dimensional ideas at the early stages is based on the game. The learner is invited to build on the computer display a simple 3-dimensional structure through 3D preset elements by way of moving these elements into their positions in accordance with the given pattern, the necessary minimum toolbar being placed on display.

After completing this task the learner is invited to have a “look” at his design from another point of view, i.e. to rotate his 3D model to some angle. After the learner’s several failures the teacher’s corresponding explanations, the teacher switches on the multi-screen mode using orthogonal projections, and the learner can get a correct solution of the problem. Besides, the learner comes to understand that an “absolutely correct” construction can be achieved through using so- called “object relations” which are important in any construction process.

At the following stage of studying the learner is invited to more complicated problems which involve not only moving the constituents of the model in different planes but also to rotating them around different axes. At this stage the learner masters the important section of descriptive geometry - methods of projection transformations.

It needs to be noted that the learner can easily switch on/off the coloring of the surfaces and control the visibility of lines. Thus the learner gets used to comparing the displayed 3D images with conventional drawings.

As a rule, even at the early stage some learners want not only to design objects through preset elements but to create such elements as well. Modern systems of computer graphics make possible easy solution of such problems, and learners rapidly master methods of “growing” 3D images of 2D projections, by “adding” and “subtracting” objects, etc. Gradually the teacher introduces more complicated 3D operations (shell constructions, cuts and, rounding-offs, sections, etc.). It needs to be noted that methods and rules of conventional 2D drawing are studied simultaneously with 3D graphics resulting from 3D modeling rather than the reverse as is presently accepted. Sometimes the teacher is led to prevent learners neglect of the 2D graphics.

As a useful entertainment, learners enjoy some additional (unnecessary for purely technical purposes) potentialities of computer graphics, such as complicated coloring of surfaces, creating backgrounds and foregrounds, etc. Generally, introducing game elements into the teaching process results in increasing the learner’s interest.

If we consider that 3D modeling (without computers) emerged much earlier than present descriptive geometry and 2D drawing based on it, the existing sequence of teaching should probably be changed.