The strange form escapes a performance result : put the barrel - drain gum piece therein the one dish of central , and put dish in the transparent cup top . put moreover a piece of dish on the round gum piece , make this gum piece clip in two dish middles , but this gum piece can see clearly in the hole eye of the top dish . the magician squeezes two slices of dishs by hand , making the gum piece cut through its nether dish and fall in the cup 变色筹码效果：魔术师展示一个桔色的和一个兰色的筹码，两面交代后用兰色筹码摩檫桔色的筹码，瞬间桔色的筹码立即变成了绿色，再将绿色筹码翻过来盖在兰色筹码上，瞬间兰色筹码立即变成了红色，而覆盖的绿色筹码又变成了桔色！最后两个筹码都可以交给观众检查。
In the process of developing the system , the paper discusses in - depth some key technologies such as spatial index of triangulated irregular network ( tin ) data , the integration of multi - source data , the process of dem & texture data , the application of lod in real - time animation , the technique of clipping in 3d landscape , the stereo synchronizati on , the multithreading 在系统开发过程中深入研究了几项关键技术：三角网索引、多源数据的集成、数字高程模型与纹理数据的处理、实时动画中的lod 、三维景观中的裁剪、立体同步以及多线程。
