Question

怎么把cad三维坐标改成二维坐标？

Answer 1

那要看怎么投影了
直接去掉z坐标也是变成2D的，只不过是把z坐标都压缩在一个平面了
下面的是轴测图
Option Base 1
Private Type LineNum
sP As Integer
eP As Integer
End Type
Dim px(), py(), pz()
Dim pt(12, 4)
Dim ln(18) As LineNum
Dim lp1(6) As POINTAPI

Private Sub Form_Load()
Show
px = Array(-180, -320, -320, -250, -250, -180, -180, -320, -320, -250, -250, -180)
py = Array(0, 0, 0, 0, 0, 0, 120, 120, 120, 120, 120, 120)
pz = Array(50, 50, 110, 110, 200, 200, 50, 50, 110, 110, 200, 200)
pl = Array(1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 1, 7, 8, 8, 9, 9, _
10, 10, 11, 11, 12, 12, 7, 1, 7, 2, 8, 3, 9, 4, 10, 5, 11, 6, 12)
For i = 1 To 12
pt(i, 1) = px(i)
pt(i, 2) = py(i)
pt(i, 3) = pz(i)
pt(i, 4) = 1
Next
For i = 1 To 18
ln(i).sP = pl(2 * i - 1)
ln(i).eP = pl(2 * i)
Next i

Dim t0(4, 4), t(4, 4), p(12, 4)
Unit3D t0()
zhouce t
Mat3D t0(), t()
Mat3D1 pt, t0, p, 12
For i = 1 To 18
pic.Line (p(ln(i).sP, 1), p(ln(i).sP, 2))-(p(ln(i).eP, 1), p(ln(i).eP, 2))
Next
For i = 1 To 6
lp1(i).x = p(i, 1): lp1(i).y = p(i, 2)
Next

End Sub

'Option Explicit
Option Base 1
Const AXIS_X = &H1 'X轴
Const AXIS_Y = &H2 'Y轴
Const AXIS_Z = &H3 'Z轴
Public Const PS_SOLID = 0

Public Type POINTAPI
x As Long
y As Long
End Type

Public Sub Unit3D(t()) '生成单位矩阵
For i = 1 To 4
For j = 1 To 4
t(i, j) = 0
Next j
t(i, i) = 1
Next i
End Sub

Public Sub Scale3D(t(), cx, cy, cz) '比例变换矩阵
Unit3D t
t(1, 1) = cx
t(2, 2) = cy
t(3, 3) = cz
End Sub

Public Sub Move3D(t(), dx, dy, dz) '平移变换矩阵
Unit3D t
t(4, 1) = dx
t(4, 2) = dy
t(4, 3) = dz
End Sub

Public Sub Rotate3D(t(), asix%, alf) '绕某一个坐标轴旋转alf角的变换矩阵
'asix为常量，&H1代表X轴，&H2代表Y轴，&H3代表Z轴
Unit3D t
Select Case asix
Case AXIS_X
t(2, 2) = Cos(alf): t(2, 3) = Cos(alf)
t(3, 2) = Sin(alf): t(3, 3) = -Sin(alf)
Case AXIS_Y
t(1, 1) = Cos(alf): t(1, 3) = Cos(alf)
t(3, 1) = Sin(alf): t(3, 3) = -Sin(alf)
Case AXIS_Z
t(1, 1) = Cos(alf): t(1, 2) = Cos(alf)
t(2, 1) = Sin(alf): t(2, 2) = -Sin(alf)
End Select
End Sub

Public Sub Shear3D(t(), shxy, shxz, shyz, shyx, shzx, shzy)
'后六个参数分别为：
'沿x含y错切,沿x含z错切
'沿y含z错切,沿y含x错切
'沿z含x错切,沿z含y错切的系数
t(1, 2) = shyx: t(1, 3) = shzx
t(2, 1) = shxy: t(2, 3) = shzy
t(3, 1) = shxz: t(3, 2) = shyz
End Sub

Public Sub Pers(t(), q) '透视变换矩阵
Unit3D t
t(2, 4) = q
End Sub

Public Sub Mat3D(a(), b()) '矩阵相乘子程序
Dim c(4, 4)
For i = 1 To 4
For j = 1 To 4
c(i, j) = 0
For k = 1 To 4
c(i, j) = c(i, j) + a(i, k) * b(k, j)
Next k
Next j
For j = 1 To 4
a(i, j) = c(i, j)
Next j
Next i
End Sub

Public Sub Mat3D1(a(), t(), c(), n) '矩阵变换子程序
For i = 1 To n
For j = 1 To 4
c(i, j) = 0
For k = 1 To 4
c(i, j) = c(i, j) + a(i, k) * t(k, j)
Next k
Next j
For j = 1 To 3
If (Abs(c(i, 4) > 0.00000001)) Then
c(i, j) = c(i, j) / c(i, 4)
Else
c(i, j) = 999
End If
Next j
Next i
End Sub

Public Sub zhouce(t())
Unit3D t
t(1, 1) = -0.7071
t(1, 2) = -0.4082
t(2, 1) = 0.7071
t(2, 2) = -0.4082
t(3, 2) = 0.8165
t(3, 3) = 0
End Sub

Public Sub xie2(t())
Unit3D t
t(2, 1) = -0.354
t(2, 2) = -0.354
End Sub

Answer 2

CAD的工具栏中有一个叫“视觉样式”的共具里面的第一个是“二维线框”点击它就可以了

Answer 3

命令输入plan 然后再输入W就OK了

Answer 4

看看这个方法吧，见附图

Answer 5

视图  动态观察 自由动态观察