【摘要】 为了勾勒点云的骨架或在点云上标记符号,提出一种基于手绘的点云表面曲线构造方法.首先将手绘的二维草图识别成二次曲线;然后将其均匀离散化并分别投影到点云表面;最后判断投影点是否接近于同一平面,如果是,则将二次曲线重新投影到该拟合平面;否则,将投影点连接成B-样条曲线并对其平滑去噪.实验结果表明,利用该方法可以快速勾勒出点云轮廓,并在点云表面高效地绘制出二次曲线或者平滑的B样条曲线.更多还原

【Abstract】 To outline the silhouette of point cloud or mark some special signs on it,a novel approach for creating curves on point cloud with free-hand sketch is presented.The raw sketch made by free-hand tracing is first recognized as a set of conics and line segments,then the conics are equi-distantly sampled,and all the sampled points are projected back onto the point cloud.Finally,all these projected points are verified to see whether they lie well on a plane.If it does,re-project the conics onto the plane.Else,fit the projected points as a B-spline curve and smooth it.Experiments show that silhouette can be perfectly and quickly outlined based on this free-hand sketching.Conics or smooth 3D B-spline curve can be drawn freely and quickly.更多还原