摘要： 背景当前3D图形界主要有两个：微软的Direct 3D以及某组织的OpenGL。曾经一度OpenGL几乎占据所有3D图形领域，这在巨人微软面前简直就是屌丝逆袭。曾几何时微软搞IDE borland公式倒闭了，后来微软搞浏览器，网景公司解散，员工卷铺盖走人了，也就是说微软搞谁，谁倒霉。直到OpenGL的出现，打破了这一魔咒，在与微软竞争的前期，OpenGL几乎甩了微软几条街，并成为事实上的工业标准。后来在微软的大力绞杀下，OpenGL几乎被完全赶出了游戏领域，退居高端图形领域。基本上现在是微软的Direct 3D统治游戏领域，而OpenGL则在高端专业图形领域占绝对统治地位。微软还是微软，Ope 阅读全文

摘要： When an object is placed in the world using translations and rotations it becomes hard to find its world coordinates. In this section a simple technique to find the whereabouts in world coordinates of an object is presented. It is assumed that the object is rendered in the local origin. The techniqu 阅读全文

摘要： The spherical version is a simple extension to the cylindrical case. After the object is rotated using the cylindrical approach, all that is left to do is to tilt the object until it truly faces the camera.球体版本的广告牌是圆柱体广告牌的一个简单扩展。在使用圆柱广告牌技术将物体旋转之后，所剩下的工作就是使物体倾斜以达到真正面对照相机的效果。The axis of rotation is th 阅读全文

摘要： True cylindrical billboarding constraints the objects rotation to an axis, as in the cheating version, but the look at vector from the object will be rotated in the camera's direction, restricted to the plane defined by the up vector, and the center of the local origin. The following image shows 阅读全文