page4 Geometry几何

page4
Geometry几何
visible objects in the scene graph场景中显示对象
What is a Geometry?
1:A geometry is the type of spatial that is actually visible on the screen (Geometry几何是spatial空间的一种类型，可以实际显示可见)
2：A geometry has a mesh to define its form and a material to define the appearace(几何体有网格 mesh来定义它的材质和外观)

geometry.setMaterial(redMaterial);设置材质，红色材质