Spiral in 3D

It's very simple in 2007 or 2008. Very difficult with 2006 or before. Which version do you use?

With 2000, one way is to build a torus, cut ir in 4 equal parts. make a little rotation for parts 2 3 4, another one same angle) for parts 3 and 4 and another one (same angle) for part 4 in such a way to get 1 turn spiral and copy as many times as necessary. Problem: it's not a real spiral...

No, it's not:

Hiya

No sweat. Here's the routine, test it a few times to get the feel for it. I suggest you draw a circle first then pick the circle's center as a reference point as this routine does not give you one nor can you pick the center of the spring once created. I hope I made sense.

Dr Fleau

;Tip1736b: 3DSPIRAL.LSP Create 3D spring

;;; 3DSPIRAL.LSP ;;; Copyright (C) 1993 by Autodesk, Inc. ;;; ;;; Permission to use, copy, modify, and distribute this software ;;; for any purpose and without fee is hereby granted, provided ;;; that the above copyright notice appears in all copies and that ;;; both that copyright notice and this permission notice appear in ;;; all supporting documentation. ;;; ;;; THIS SOFTWARE IS PROVIDED "AS IS" WITHOUT EXPRESS OR IMPLIED ;;; WARRANTY. ALL IMPLIED WARRANTIES OF FITNESS FOR ANY PARTICULAR ;;; PURPOSE AND OF MERCHANTABILITY ARE HEREBY DISCLAIMED. ;;;

--------------------------------------------------------------------------; ;;; DESCRIPTION ;;; ;;; This is a programming example. ;;; ;;; Designed and implemented by Kelvin R. Throop in January 1985 ;;; Modified by Bill Zondlo 12/30/99 to be used with SOL_SPRING.LSP. ;;; This program now contains 3DSpiral.lsp only. ;;;

--------------------------------------------------------------------------;

(defun myerror (s) ; If an error (such as CTRL-C) occurs ; while this command is active... (if (/= s "Function cancelled") (princ (strcat "\nError: " s)) ) (setvar "cmdecho" ocmd) ; Restore saved modes (setvar "blipmode" oblp) (setq *error* olderr) ; Restore old *error* handler (princ) )

(defun cspiral (ntimes bpoint hfac lppass strad vfac / ang dist tp ainc dhinc dvinc circle dv)

(setvar "blipmode" 0) ; turn blipmode off (setvar "cmdecho" 0) ; turn cmdecho off (setq circle (* 3.141596235 2)) (setq ainc (/ circle lppass)) (setq dhinc (/ hfac lppass)) (if vfac (setq dvinc (/ vfac lppass))) (setq ang 0.0) (if vfac (setq dist strad dv 0.0) (setq dist 0.0) ) (if vfac (command "_3dpoly") ; start spiral ... (command "_pline" bpoint) ; start spiral from base point and... ) (repeat ntimes (repeat lppass (setq tp (polar bpoint (setq ang (+ ang ainc)) (setq dist (+ dist dhinc)) ) ) (if vfac (setq tp (list (car tp) (cadr tp) (+ dv (caddr tp))) dv (+ dv dvinc) ) ) (command tp) ; continue to the next point... ) ) (command "") ; until done. (princ) )

;;; ;;; Interactive spiral generation ;;;

(defun C:3DSPIRAL (/ olderr ocmd oblp nt bp hg vg sr lp) (setq olderr *error* *error* myerror) (setq ocmd (getvar "cmdecho")) (setq oblp (getvar "blipmode")) (setvar "cmdecho" 0) (initget 1) ; bp must not be null (setq bp (getpoint "\nCenter point: ")) (initget 7) ; nt must not be zero, neg, or null (setq nt (getint "\nNumber of rotations: ")) (initget 7) ; sr must not be zero, neg, or null (setq sr (getdist bp "\nStarting radius: ")) (initget 1) ; cf must not be zero, or null (setq hg (getdist "\nHorizontal growth per rotation: ")) (initget 3) ; cf must not be zero, or null (setq vg (getdist "\nVertical growth per rotation: ")) (initget 6) ; lp must not be zero or neg (setq lp (getint "\nPoints per rotation : ")) (cond ((null lp) (setq lp 30))) (cspiral nt bp hg lp sr vg) (setvar "cmdecho" ocmd) (setvar "blipmode" oblp) (setq *error* olderr) ; Restore old *error* handler (princ)

) ;;;

--------------------------------------------------------------------------; (princ "\n\tC:3DSPIRAL loaded. ") (princ)