目前我正在研究对象识别系统，这需要大量的训练数据。
我正在尝试将 3D 模型转换为一系列灰度图像，旋转模型并以一定的时间间隔对 2D 图像进行采样。
因为我主要在做python，所以我尝试基于pygame和pyopenGL解决这个问题，我找到了这个加载.obj文件的例子，但一开始它不会工作，花了我很长时间找出问题出在哪里。
现在核心问题以某种方式简化为如下：
Point3D 类：
def __init__(self, x = 0, y = 0, z = 0):
self.x, self.y, self.z = float(x), float(y), float(z)
def rotateX(self, angle):
""" Rotates the point around the X axis by the given angle in degrees. """
rad = angle * math.pi / 180
cosa = math.cos(rad)
sina = math.sin(rad)
y = self.y * cosa - self.z * sina
z = self.y * sina + self.z * cosa
return Point3D(self.x, y, z)
def rotateY(self, angle):
""" Rotates the point around the Y axis by the given angle in degrees. """
rad = angle * math.pi / 180
cosa = math.cos(rad)
sina = math.sin(rad)
z = self.z * cosa - self.x * sina
x = self.z * sina + self.x * cosa
return Point3D(x, self.y, z)
def rotateZ(self, angle):
""" Rotates the point around the Z axis by the given angle in degrees. """
rad = angle * math.pi / 180
cosa = math.cos(rad)
sina = math.sin(rad)
x = self.x * cosa - self.y * sina
y = self.x * sina + self.y * cosa
return Point3D(x, y, self.z)
def project(self, win_width, win_height, fov, viewer_distance):
""" Transforms this 3D point to 2D using a perspective projection. """
factor = fov / (viewer_distance + self.z)
x = self.x * factor + win_width / 2
y = -self.y * factor + win_height / 2
return Point3D(x, y, self.z)
类模拟：
def __init__(self, win_width = 640, win_height = 480):
pygame.init()
self.screen = pygame.display.set_mode((win_width, win_height))
pygame.display.set_caption("Simulation of a rotating 3D Cube (http://codeNtronix.com)")
self.clock = pygame.time.Clock()
self.vertices = [
Point3D(-1,1,-1),
Point3D(1,1,-1),
Point3D(1,-1,-1),
Point3D(-1,-1,-1),
Point3D(-1,1,1),
Point3D(1,1,1),
Point3D(1,-1,1),
Point3D(-1,-1,1)
]
# Define the vertices that compose each of the 6 faces. These numbers are
# indices to the vertices list defined above.
self.faces = [(0,1,2,3),(1,5,6,2),(5,4,7,6),(4,0,3,7),(0,4,5,1),(3,2,6,7)]
# Define colors for each face
self.colors = [(255,0,255),(255,0,0),(0,255,0),(0,0,255),(0,255,255),(255,255,0)]
self.angle = 0
def run(self):
""" Main Loop """
while 1:
for event in pygame.event.get():
if event.type == pygame.QUIT:
pygame.quit()
sys.exit()
self.clock.tick(50)
self.screen.fill((0,32,0))
# It will hold transformed vertices.
t = []
for v in self.vertices:
# Rotate the point around X axis, then around Y axis, and finally around Z axis.
r = v.rotateX(self.angle).rotateY(self.angle).rotateZ(self.angle)
# Transform the point from 3D to 2D
p = r.project(self.screen.get_width(), self.screen.get_height(), 256, 4)
# Put the point in the list of transformed vertices
t.append(p)
# Calculate the average Z values of each face.
avg_z = []
i = 0
for f in self.faces:
z = (t[f[0]].z + t[f[1]].z + t[f[2]].z + t[f[3]].z) / 4.0
avg_z.append([i,z])
i = i + 1
# Draw the faces using the Painter's algorithm:
# Distant faces are drawn before the closer ones.
for tmp in sorted(avg_z,key=itemgetter(1),reverse=True):
face_index = tmp[0]
f = self.faces[face_index]
pointlist = [(t[f[0]].x, t[f[0]].y), (t[f[1]].x, t[f[1]].y),
(t[f[1]].x, t[f[1]].y), (t[f[2]].x, t[f[2]].y),
(t[f[2]].x, t[f[2]].y), (t[f[3]].x, t[f[3]].y),
(t[f[3]].x, t[f[3]].y), (t[f[0]].x, t[f[0]].y)]
pygame.draw.polygon(self.screen,self.colors[face_index],pointlist)
self.angle += 1
pygame.display.flip()
if name == " main ": Simulation().run()
上面的例子画了一个立方体，一直在旋转，那我怎么能直接得到像素数据呢？什么库或包可以提供我直接获取2D项目的像素数据的能力。（IPL？或 pyopenGL？）
谢谢