The distinct feature of this approach is to reconstruct the 3d model of target from images progressively in accordance with the general modeling conventions . namely , user firstly determines the rough model and puts projection and spatial constraints on it as well as topological operations step by step to let the system recover the camera parameters and refine the model 該方法的主要特點在于,按照一般人的建模習慣,由粗到細地通過圖像重建目標三維模型,在確定大致形狀的基礎上,由用戶添加或者修改投影約束與空間約束,并施加拓撲修改,逐步實現照相機定標,粗糙模型的求精,并最終完成對具有任意幾何及拓撲物體的重建。