first-angle projection meaning in Chinese

第一角投影
第一象限投影法
首角投影法

In china , the first - angle projection is adopted preferencially following related national standards
国家标准规定，我国优先采用第一角画法绘制机件的图样。
From the practical view , this paper summarizes the theory of orthogonal projection based on the first - angle projection , the ways of manual reading drawings and discusses the problems relevant . the mechanism similar with csg is used to reconstruct 3d object with priority to csg and aid by b - rep
本文从实用的角度出发，总结了正投影工程图中的投影理论基础、人工读图方法以及注意的相关问题，采用了以csg方法为主， b ? rep方法为辅，类似于csg建模的机制来实现二维视图的三维重建过程。