def matrix(self):
"""Get the camera matrix to convert object from world coordinate
to camera coordinate
"""
if self.__matrix is not None:
return self.__matrix
# calculate matrices
translation = [
[1, 0, 0, -self.position.x],
[0, 1, 0, -self.position.y],
[0, 0, 1, -self.position.z],
[0, 0, 0, 1]
]
trans_mat = Matrix.new(translation)
camera_zaxis = self.facing_dir.unit_vector
camera_yaxis = self.up_dir.unit_vector
camera_xaxis = camera_yaxis.cross(camera_zaxis).unit_vector
alignment = [
[*camera_xaxis.to_list(), 0],
[*camera_yaxis.to_list(), 0],
[*camera_zaxis.to_list(), 0],
[0, 0, 0, 1]
]
alignment_mat = Matrix.new(alignment)
# now, we have our world coordinate aligned with camera coordinate
# calculate projection matrix
proj_mat = self.projection.matrix
self.__matrix = proj_mat * alignment_mat * trans_mat
return self.__matrix
def transform_point(self, point3d):
pointarr = [*point3d.to_list(), 1.]
pointmatrix = Matrix.new([[x] for x in pointarr])
result = self.camera.matrix * pointmatrix
z = result.array[-1][0]
x = result.array[0][0]
y = result.array[1][0]
try:
return [x/z, y/z]
except Exception as e: # DivisionByZero in fact
return None
def matrix(self):
if self.__matrix is not None:
return self.__matrix
d = self.plane_distance
projection = [
[d, 0, 0, 0],
[0, d, 0, 0],
[0, 0, d, 0],
# we want w coordinate of projected point to be the z coordinate
[0, 0, 1, 0],
]
self.__matrix = Matrix.new(projection)
return self.__matrix
