在图像上叠加图像

Question

Implement the function tree that takes a number of slices n and a rune as arguments, and generates a stack of runes scaled and overlayed on top of each other.

For example, the following command tree(4, circle_bb) should produce the following depth map:

The generated tree must satisfy a few properties: the circle bb at the top of the tree is scaled to 1=4 of its original size (the tree has 4 layers); the next lower layer is scaled by 2=4, and so on. Note that the bottom-most layer retains its original size. The different levels of the tree must also be spaced evenly apart.

要使用overlay_frac（比率，pattern1，pattern2）和scale（size，pattern）命令。在

对于overlay_frac，此参数确定 第一符文占据深度范围的一部分；剩余部分 深度范围将被第二个符文占据。在

我的代码特别显示（树（4，圆圈峎bb））是：

def tree(n, rune):
    a= scale( 1/n, rune)
    b = scale( 2/n, rune)
    c = scale( 3/n, rune)
    Bottom = overlay_frac( 1/2, c,d)
    Middle = overlay_frac(1/2, b, Bottom)
    Top = overlay_frac(1/2, a, Middle)

    return Top

但我需要换成一个循环，所以我写下：

^{pr2}$

然而，它给人的形象是不同的。我做错什么了？在

Answer 1

循环中有一个return语句，因此它在第一次迭代之后退出。在