这段代码的特点是能够根据曲线的曲率分配顶点数,曲率变化大的地方顶点的密度大。

- [FONT=courier new]
- ;__2004.01.12.09.43_____________________________________
- ;__样条曲线--〉复义线___BY__WKAI__晓东CAD论坛___________
- (defun c:tt (/ pts min_distacne vlo st_par ed_par ent n max_angle_rad max_an)
- (setq vlo (vlax-ename->vla-object (setq ent (car (entsel "\n选择spline:"))))
- st_par (vlax-curve-getstartparam vlo)
- ed_par (vlax-curve-getendparam vlo)
- pts (list (vlax-curve-getstartpoint vlo))
- max_angle (if (setq max_an (getreal (strcat "\n许可角度误差<"
- (if max_angle
- (rtos max_angle 2 2)
- (rtos (setq max_angle 5) 2 2)
- )
- ">:"
- )
- )
- )
- max_an
- max_angle
- )
- max_angle_rad (* pi (/ max_angle 180.0)) ;_最大许可误差角度弧度
- )
- (setq zhf_time_dot nil)
- (z_timer)
- (t1 vlo st_par ed_par)
- (command "pline")
- (foreach n pts (command "non" n))
- (command)
- (princ (strcat "\n创建一条顶点数为" (itoa (length pts)) "的复义线。"))
- (princ (z_timer))
- (princ)
- )
- ;________________________________________________________
- ;________________________________________________________
- (defun t1 (vl_obj start_par end_par / dis_m_m ed_p ed_pt mid_p mid_pt mid_pt_vlo st_p st_pt)
- (setq st_p start_par
- ed_p end_par
- st_pt (vlax-curve-getpointatparam vl_obj st_p)
- ed_pt (if (vlax-curve-getpointatparam vl_obj ed_p)
- (vlax-curve-getpointatparam vl_obj ed_p)
- (vlax-curve-getendpoint vl_obj)
- )
- mid_p (/ (+ st_p ed_p) 2.0)
- mid_pt (mapcar '(lambda (x y) (/ (+ x y) 2.0)) st_pt ed_pt)
- mid_pt_vlo (vlax-curve-getpointatparam vl_obj mid_p)
- dis_m_m (distance mid_pt_vlo mid_pt)
- )
- (if (or (> (t3 ed_pt st_pt mid_pt_vlo t) max_angle_rad)
- (and (< (t3 ed_pt st_pt mid_pt_vlo t) max_angle_rad)
- (t2 vl_obj st_p ed_p st_pt ed_pt)
- )
- )
- (progn
- (t1 vl_obj st_p mid_p)
- (t1 vl_obj mid_p ed_p)
- )
- (setq pts (append pts (list mid_pt_vlo) (list ed_pt)))
- )
- )
- ;_____________________________________________________________
- (defun t2 (vl st_par ed_par s_pt e_pt / run delta_p n lst pt)
- (setq run t
- delta_p (- ed_par st_par)
- lst '(0.0001 0.01 0.25) ;_测试采样表
- n -1
- )
- (while (and run (< (setq n (1+ n)) (length lst)))
- (setq pt (vlax-curve-getpointatparam vl (+ st_par (* delta_p (nth n lst)))))
- (if (> (t3 e_pt s_pt pt t) max_angle_rad)
- (setq run nil)
- )
- (if (> (t3 s_pt e_pt pt t) max_angle_rad)
- (setq run nil)
- )
- (setq pt (vlax-curve-getpointatparam vl (- ed_par (* delta_p (nth n lst)))))
- (if (> (t3 e_pt s_pt pt t) max_angle_rad)
- (setq run nil)
- )
- (if (> (t3 s_pt e_pt pt t) max_angle_rad)
- (setq run nil)
- )
- )
- (not run)
- )
- ;_____________________________________________________________
- (defun t3 (p1 p2 p3 rad)
- (if rad
- (abs (- (angle p2 p3) (angle p2 p1)))
- (* 180 (/ (abs (- (angle p2 p3) (angle p2 p1))) pi))
- )
- )
- ;________________________________________________________
- ;________________________________________________________
- (princ "\n样条曲线--〉复义线___BY__WKAI__晓东CAD论坛") [/FONT]
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