question in function get_text_placement_mask(xyz,mask,plane,pad=2,viz=False):

[CatherineYao]

In synthgen.py, I know that pts is points of contour in 2d image and pts_fp is where these points should be in fronto-parallel. But what does pts_tmp mean?
rect = cv2.minAreaRect(pts_fp[0].copy().astype('float32'))
box = np.array(cv2.cv.BoxPoints(rect))
R2d = su.unrotate2d(box.copy())
box = np.vstack([box,box[0,:]]) #close the box for visualization

mu = np.median(pts_fp[0],axis=0)
pts_tmp = (pts_fp[0]-mu[None,:]).dot(R2d.T) + mu[None,:]
boxR = (box-mu[None,:]).dot(R2d.T) + mu[None,:]
s = rescale_frontoparallel(pts_tmp,boxR,pts[0])

Why does these codes necessary ? Why pts_fp and box cant't use in function “rescale_frontoparallel " directlly but use pts_tmp and boxR?

[CatherineYao]

I got it.