According to mechanism of orthographic projection, this paper has set up the converted relation between screen coordinate and space coordinate.
根据正投影的机理，建立了点线面屏幕坐标与空间关系的转换关系。
2
On this basis, mathematical model of depth recovery according to "circle-depth relation" algorithm and projection rules was constructed.
在此基础上，构建了基于“半径—深度”算法和空间投影关系的深度恢复模型。
3
The relation among the angles of femoral anteversion, neck-shaft and projection of femoral neck and shaft was researched by imitating. And its clinical significance was discussed.