这个真是个难题，现在我把下载的一个做法提供给大家，供参考3 A$ d+ w4 R! J& J, Y
1.先用直线命令画一直线（图1）。过程如下：
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% k2 a; q7 f; t) o: \$ c 命令: LINE
+ e) G+ w6 P1 A0 {# o' d/ C; h 指定第一点: 0,0+ B4 J% p6 i4 z: ~# n+ c$ c
指定下一点或 [放弃(U)]: 'cal
4 K9 G: B* ^# `( b >> 表达式: +[100*100/200<-30]$ E4 r+ X2 l2 r8 Y! l! l& S1 G
(43.3013 -25.0 0.0): N% o! l g. Y# U. m
指定下一点或 [放弃(U)]: ↙/ Q" ^' ~! f- M7 j6 C$ S3 E8 d% v T7 a
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, ?2 c: x+ A" a: _4 y- K$ ` 2.移动该直线，如图2。9 S8 B# Z; E1 F2 A
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3.用多段线命令画多段线，先向-60度方向拉出适当长度，如图3。, f5 M3 j5 V2 L( @+ D6 x2 [; a
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4.继续画多段线，完成一个直角三角形，如图4。
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5.用REVOLVE命令旋转直角三角形，生成一个三维实体，如图5。过程如下：* f6 T+ G6 t8 j4 h9 f+ ~% X
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命令: REVOLVE
( w8 j7 {: {, H" R4 e: X6 A% W: i 当前线框密度: ISOLINES=46 v- h9 d* _' [- _& W4 m8 p
选择对象:（选择直角三角形）
- R4 M9 L1 N& `- s) t 选择对象: ↙
# m* t+ U) e2 G/ N2 X. N9 O 指定旋转轴的起点或( x0 k/ H6 N# X" J' k9 m
定义轴依照 [对象(O)/X 轴(X)/Y 轴(Y)]:（捕捉A点）
. Z3 R' p2 E& l# w: s+ |# `% c* x 指定轴端点: （捕捉B点）3 h9 t) O9 B( _6 y" c, q, U a
指定旋转角度 <360>:↙% o @4 }) p& d5 @) V9 M: Y6 A
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6.用SECTION命令切割三维实体，生成一个面域，如图6。过程如下：6 x5 ?8 v1 Z2 u7 {, x% v' t. q
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命令: SECTION
3 ^1 U! [8 i" ~3 t' k 选择对象: (选择上一步生成的旋转实体)5 W' y% P1 Z' w2 r2 c
选择对象: ↙* }1 @# G1 h6 h9 l: z
指定截面上的第一个点，依照 [对象(O)/Z 轴(Z)/视图(V)/XY 平面(XY)/YZ 平面(YZ)/ZX 平面(ZX)/三点(3)] <三点>: yz
; Q- o! L! I, z; ~$ k 指定 YZ 平面上的点 <0,0,0>:（捕捉C点）8 H5 p9 D% c" }# B1 x9 n, U& _! p
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7.用rotate3d命令对上一步生成的面域进行三维旋转，如图7。过程如下：6 h# D6 g& _7 ]0 s5 N5 h6 _3 `* @) \: F
4 l0 Y# }' H, t* n& Z5 k 命令: rotate3d
1 O4 F, m9 j* N# V. i$ V! ` Y/ N 当前正向角度: ANGDIR=逆时针 ANGBASE=0
9 M+ [2 a6 `8 y( W- z 选择对象: （选择上一步生成的面域）
% ^& y5 S- D. z+ h 选择对象: ↙
. E G+ X: B O 指定轴上的第一个点或定义轴依据[对象(O)/最近的(L)/视图(V)/X 轴(X)/Y 轴(Y)/Z 轴(Z)/两点(2)]: (捕捉C点) 指定轴上的第二点:（捕捉D点）; R. S5 k* s7 j7 G, a
指定旋转角度或 [参照(R)]: 908 G! d* N1 @7 n, g. p
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8.先用EXPLODE命令分解旋转后的面域，再清理图面，删除不需要的图元，如图8。7 E6 Z& l$ C6 `$ |" } {: [7 F6 |8 w
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7 ^$ e& i0 i* I2 }$ H" v9 ^ 9.移动抛物线，如图9。完毕！5 n: |9 T5 z, c+ r0 g+ j
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http://bbs.icax.cn/register.php
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Sub trparabola() b4 v. F6 z2 g5 r+ r
Dim bq1, bq2, pt1, pt2 As Variant 5 s2 b7 i# O z; s1 X" d
Dim aa, ll, yy, a1, a2, a3, a4, aa1, pt3(0 To 2), bq4(0 To 2) As Double
$ ~& I5 J- u# qDim bq3(0 To 2) As Double
! Q9 K9 u) f' X) A8 f" B2 _' I" [Dim ae As Double 6 T+ g" M: q, y" A; d: S
Dim pt33(0 To 2) As Double % @$ k: i h0 s( g9 Q( I1 Q5 C
Dim ptarr(0 To 7) As Double / h, ^! h5 L# D
Dim alt As Variant
% T# a. u# H7 T; ]1 g& Q% SDim objboltb As Acad3DSolid
" ?/ E2 W' f. A+ w8 t3 r- dDim al As Variant 5 K) N, b \) l
Dim lens As AcadLWPolyline + [! V" a/ W7 {3 B
7 P, K }* Z8 R! I'求个控制点 8 A6 y( s* `5 v5 l4 Y# T
bq1 = ThisDrawing.Utility.GetPoint(, "抛物线顶点: ") ' ]$ B* E, L4 D/ m: b' C! c
aa = ThisDrawing.Utility.GetReal("输入二次项系数： ") - g+ F- m+ u8 H- x) P* [; \' Q
ll = ThisDrawing.Utility.GetDistance(, "输入开口弦长： ")
4 R/ ]9 K; Z$ ^9 [aa1 = 1 / aa 5 Z* m3 p6 S/ Q
yy = aa * (ll / 2) ^ 2 ' |1 p) a/ D# _5 C$ ?' w: L& n& z
a1 = ThisDrawing.Utility.AngleToReal(-30, acDegrees) . r; M5 |. ]* V, i
a2 = ThisDrawing.Utility.AngleToReal(30, acDegrees) 8 y% i) G. c9 g. X( Y" O4 t$ f+ O
a3 = ThisDrawing.Utility.AngleToReal(90, acDegrees) % |& K$ \& H) q$ g: u* g
a4 = ThisDrawing.Utility.AngleToReal(150, acDegrees)
; F4 k: f. {4 i& K/ Z( E5 l# |8 Sbq2 = ThisDrawing.Utility.PolarPoint(bq1, a2, yy)
R. ~4 e, E/ s+ @2 p H% spt1 = ThisDrawing.Utility.PolarPoint(bq1, a4, aa1) 4 M; c+ S5 J9 I X% |
pt2 = ThisDrawing.Utility.PolarPoint(bq2, a3, aa1) 6 L t$ d% i ]7 L& }* s& _3 P
pt3(0) = pt2(0): pt3(1) = pt1(1): pt3(2) = pt1(2)
7 X% U: @9 t9 {4 R* fbq3(0) = bq2(0): bq3(1) = bq2(1): bq3(2) = bq2(2) + 10 , D" W' m5 H' n" ]" B1 l
bq4(0) = bq2(0): bq4(1) = bq1(1): bq4(2) = bq1(2)
3 h1 R# o2 p% |- K Y- U$ W8 F6 gpt33(0) = 10: pt33(1) = 0: pt33(2) = 0 0 g* c/ W f' a, s& }
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4 R. O! S6 M! M/ K( A: ^6 h# \7 z) D# hptarr(0) = pt1(0) 6 ~8 A* {6 r4 y' c' Y
ptarr(1) = pt1(1)
$ s& c9 ^! _; _! W# lptarr(2) = pt2(0) # k$ b9 ~ n( B! W+ j5 a
ptarr(3) = pt2(1) . K; N% z8 t+ x1 s( z
ptarr(4) = pt3(0)
; y+ l% y( {) yptarr(5) = pt3(1)
$ C9 m# S8 Q3 d4 R' A7 cptarr(6) = pt1(0) - r) \" f6 ]% N5 s& S6 ^
ptarr(7) = pt1(1)
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W6 V4 v5 _! t+ `% G' x- d'画多段线 8 e# d5 [8 l3 i
Set lens = ThisDrawing.ModelSpace.AddLightWeightPolyline(ptarr) % F9 ~0 X" ?) I$ y4 W! B
Dim objlist(0) As AcadEntity
% e) c& ?/ n/ ISet objlist(0) = lens 7 R9 @7 M# |& D) F$ ~
. E! D( g+ L/ _0 \' u+ o'将多段线变为面域 H2 d; P5 d) ?4 d& ~) \
Dim altregion As AcadRegion 7 V7 C7 e4 N2 Y) `# V/ `% M+ g$ F
alt = ThisDrawing.ModelSpace.AddRegion(objlist)
( u. ]) t" {' e% Oobjlist(0).Delete 2 \0 c9 D& T" y9 v) N
Set altregion = alt(0)
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'旋转面域得到圆锥 / w3 m- m+ k0 c. [7 U5 d# `- u
ae = 2 * Atn(1) * 4 & B: R' Z4 I0 b9 q
Set objboltb = ThisDrawing.ModelSpace.AddRevolvedSolid(altregion, pt1, pt33, ae) 7 o3 `/ W2 c6 V$ _! X! g
altregion.Delete
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' W0 h- Y4 K. A5 u3 f" g4 `. ^'切圆锥得到抛物线 + z3 G& |5 z$ S7 F# J2 x
Set al = objboltb.SectionSolid(bq1, bq2, bq3)
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al.Rotate bq1, a1 - R) F" \+ Z9 H, s$ H! F- m
al.Rotate3D bq1, bq4, a3
5 A1 r7 p$ Q2 G$ C% p# hDim explodedobjects As Variant / |6 H6 Z/ }! {5 G' n- f2 }
explodedobjects = al.Explode
D" e8 Z( N) Q! qal.Delete
$ z& g6 `& o' R4 f! f! eDim i As Integer # j9 g, b5 t/ u5 l8 R6 l2 p: E R' Z
Dim kind As String
8 Q8 x/ a1 {; r+ `0 Z4 y. mDim parabolaobject As AcadSpline
0 Y7 Q5 d# V0 `, o! _' SFor i = 0 To UBound(explodedobjects)
' L9 ]" e7 B4 zkind = explodedobjects(i).ObjectName 0 y/ `' t% v |1 M. Z8 {2 K
If kind = "AcDbLine" Then
5 a% d% E) f- k1 D5 F5 t; g4 `% Q; ]% A explodedobjects(i).Delete 0 } Y# |% g5 R7 G5 y0 M; f& p
Else
8 w* f) C" e7 T% h Set parabolaobject = explodedobjects(i) % E7 f4 s2 R% [6 q# w3 C
End If
9 ?/ @$ J! m/ m- }; n& W. rNext
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2 l3 `7 T& q$ L+ G- k'旋转抛物线 " g$ S2 J( I+ B- U3 r# r- N
ThisDrawing.SendCommand "rotate" & vbCr & "(Handent """ & parabolaobject.Handle & """)" & vbCr & "" & vbCr & bq1(0) & "," & bq1(1) & vbCr " R/ F! j% l4 w# v! z4 p
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End Sub
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楼主: hyj_9766
发表于 2009-3-29 19:47:49
要活到老学到老,所以我们年轻人更应该抓紧学习了，
