我尝试过搜索,但其他问题似乎都不像我的。我或多或少在python中尝试透视投影和旋转,并遇到了障碍。我确信我的投影方程是准确的,以及我的旋转方程;然而,当我运行它时,旋转开始正常,但开始向内旋转,直到矢量与Z轴(我旋转的轴)相同的位置。
''' Imports '''
from tkinter import Tk, Canvas, TclError
from threading import Thread
from math import cos, sin, radians, ceil
from time import sleep
''' Points class '''
class pPoint:
def __init__(self, fPoint, wWC, wHC):
self.X = 0
self.Y = 0
self.Z = 0
self.xP = 0
self.yP = 0
self.fPoint = fPoint
self.wWC = wWC
self.wHC = wHC
def pProject(self):
self.xP = (self.fPoint * (self.X + self.wWC)) / (self.fPoint + self.Z)
self.yP = (self.fPoint * (self.Y + self.wHC)) / (self.fPoint + self.Z)
''' Main class '''
class Main:
def __init__(self):
''' Declarations '''
self.wWidth = 640
self.wHeight = 480
self.fPoint = 256
''' Generated declarations '''
self.wWC = self.wWidth / 2
self.wHC = self.wHeight / 2
''' Misc declarations '''
self.gWin = Tk()
self.vPoint = pPoint(self.fPoint, self.wWC, self.wHC)
self.vPoint.X = 50
self.vPoint.Y = 60
self.vPoint.Z = -25
self.vPoint.pProject()
self.ang = 0
def initWindow(self):
self.gWin.minsize(self.wWidth, self.wHeight)
self.gWin.maxsize(self.wWidth, self.wHeight)
''' Create canvas '''
self.gCan = Canvas(self.gWin, width = self.wWidth, height = self.wHeight, background = "black")
self.gCan.pack()
def setAxis(self):
''' Create axis points '''
self.pXax = pPoint(self.fPoint, self.wWC, self.wHC)
self.pXbx = pPoint(self.fPoint, self.wWC, self.wHC)
self.pYax = pPoint(self.fPoint, self.wWC, self.wHC)
self.pYbx = pPoint(self.fPoint, self.wWC, self.wHC)
self.pZax = pPoint(self.fPoint, self.wWC, self.wHC)
self.pZbx = pPoint(self.fPoint, self.wWC, self.wHC)
''' Set axis points '''
self.pXax.X = -(self.wWC)
self.pXax.Y = 0
self.pXax.Z = 1
self.pXbx.X = self.wWC
self.pXbx.Y = 0
self.pXbx.Z = 1
self.pYax.X = 0
self.pYax.Y = -(self.wHC)
self.pYax.Z = 1
self.pYbx.X = 0
self.pYbx.Y = self.wHC
self.pYbx.Z = 1
self.pZax.X = 0
self.pZax.Y = 0
self.pZax.Z = -(self.fPoint) / 2
self.pZbx.X = 0
self.pZbx.Y = 0
self.pZbx.Z = (self.fPoint * self.wWC) - self.fPoint
def projAxis(self):
''' Project the axis '''
self.pXax.pProject()
self.pXbx.pProject()
self.pYax.pProject()
self.pYbx.pProject()
self.pZax.pProject()
self.pZbx.pProject()
def drawAxis(self):
''' Draw the axis '''
self.gCan.create_line(self.pXax.xP, self.pXax.yP, self.pXbx.xP, self.pXbx.yP, fill = "white")
self.gCan.create_line(self.pYax.xP, self.pYax.yP, self.pYbx.xP, self.pYbx.yP, fill = "white")
self.gCan.create_line(self.pZax.xP, self.pZax.yP, self.pZbx.xP, self.pZbx.yP, fill = "white")
def prePaint(self):
self.vA = self.gCan.create_line(self.wWC, self.wHC, self.vPoint.xP, self.vPoint.yP, fill = "red")
def paintCanvas(self):
try:
while True:
self.ang += 1
if self.ang >= 361:
self.ang = 0
self.vPoint.X = (self.vPoint.X * cos(radians(self.ang))) - (self.vPoint.Y * sin(radians(self.ang)))
self.vPoint.Y = (self.vPoint.X * sin(radians(self.ang))) + (self.vPoint.Y * cos(radians(self.ang)))
self.vPoint.pProject()
self.gCan.coords(self.vA, self.wWC, self.wHC, self.vPoint.xP, self.vPoint.yP)
self.gWin.update_idletasks()
self.gWin.update()
sleep(0.1)
except TclError:
pass
mMain = Main()
mMain.initWindow()
mMain.setAxis()
mMain.projAxis()
mMain.drawAxis()
mMain.prePaint()
mMain.paintCanvas()
感谢您的任何意见:)
编辑:对不起,我刚才意识到我忘了提问。我只是想知道为什么它会向内倾斜,而不仅仅是“正常”旋转?答案 0 :(得分:1)
这部分错了:
self.ang += 1
if self.ang >= 361:
self.ang = 0
self.vPoint.X = (self.vPoint.X * cos(radians(self.ang))
- self.vPoint.Y * sin(radians(self.ang)))
self.vPoint.Y = (self.vPoint.X * sin(radians(self.ang))
+ self.vPoint.Y * cos(radians(self.ang)))
self.vPoint.pProject()
有两个原因:
self.ang
将在开放范围[0 - 360]中取整数,这意味着重复角度360(== 0)。答案 1 :(得分:1)
与您的问题无关,但我强烈建议您使用Numpy执行几何变换,特别是如果它涉及3D点。
下面,我发布了一个示例代码段,希望有所帮助:
import numpy
from math import radians, cos, sin
## suppose you have a Nx3 cloudpoint (it might even be a single row of x,y,z coordinates)
cloudpoint = give_me_a_cloudpoint()
## this will be a rotation around Y azis:
yrot = radians(some_angle_in_degrees)
## let's create a rotation matrix using a numpy array
yrotmatrix = numpy.array([[cos(yrot), 0, -sin(yrot)],
[0, 1, 0],
[sin(yrot), 0, cos(yrot)]], dtype=float)
## apply the rotation via dot multiplication
rotatedcloud = numpy.dot(yrotmatrix, pointcloud.T).T # .T means transposition