相机与y轴成一定角度的水平旋转

Question

我目前正在用pygame创建一条透视3D道路，并试图将相机在y轴上从0度旋转到360度。但当相机与y轴的夹角大于90度时，我在屏幕上看到的图像会翻转，向前移动实际上会导致相机向后移动。。。

我对180度角的期望是什么；在"后面"；相机，但这不是我得到的。

这是我用来投影和旋转世界的代码，我猜我的数学在某个地方是错误的，因为sin/cos的属性，但我找不到问题的原因。。。

def rotate2DPoint(x,y, angle):
"""rotate 2d point in an angle"""
return cos(angle)*x-sin(angle)*y, sin(angle)*x+cos(angle)*y
def rotate3Dpoint(x,y,z,angleX=0,angleY=0, angleZ = 0):
"""rotate a 3D point in an angle """
x,z = rotate2DPoint(x,z,angleY)
y,z = rotate2DPoint(y,z,angleX)
x,y = rotate2DPoint(x,y,angleZ)
return x,y,z
def project(x,y,z, camera):
"""project a 3D point to 2D screen
returns screen x,y and the scale factor"""
# Translate the points to be reletive to the camera
x_distance = x - camera.location["x"]   #distance from the camera on x 
y_distance = y - camera.location["y"]   #distance from the camera on y 
z_distance = z - camera.location["z"]   #distance from the camera on z 
# get the projection factor
factor = camera.depth / (z_distance or 0.1)     # don't divide in 0...
# rotate :
x_distance,y_distance, z_distance = rotate3Dpoint(x_distance,y_distance, z_distance, angleY = camera.angleY, angleX= camera.angleX, angleZ = camera.angleZ)
# project:
x = int(SCREEN_WIDTH/2 + factor * x_distance )       
y = int(SCREEN_HEIGHT/2 - factor * y_distance )     

return x,y, factor    

只有相机的Y角度不同于0。对于道路，我只存储一个点，所以对于道路的每一部分，我都投影一个点。

Answer 1

在几乎放弃之后，我发现了问题。。我在计算因子后旋转，而不是在。。。这防止了新的CCD_ 1影响投影。

因此正确的功能是：

def project(x,y,z, camera):
"""project a 3D point to 2D screen
returns screen x,y and the scale factor"""

x_distance = x - camera.location["x"]   
y_distance = y - camera.location["y"]   
z_distance = z - camera.location["z"]   

x_distance,y_distance, z_distance = rotate3Dpoint(x_distance,y_distance, z_distance, angleY = camera.angleY, angleX= camera.angleX, angleZ = camera.angleZ)
factor = camera.depth / (z_distance or 0.1)     

x = int(SCREEN_WIDTH/2 + factor * x_distance )       
y = int(SCREEN_HEIGHT/2 - factor * y_distance )    

return x,y, factor