R:如何:使用 gplot 和 geom_density 绘制 3d 密度图

我正在尝试将多个密度图与叠加层结合起来.ggplot 和 geom_density 可以完成这项工作，但密度是堆叠在一起的.

I'm trying to combine multiple density plots with overlay. ggplot and geom_density do the job, but the densities are stacked on top of each other.

ggplot(all.complete, aes(x=humid_temp)) +  
  geom_density(aes(group=height, colour=height, fill=height.f, alpha=0.1)) + 
  guides(fill = guide_legend(override.aes = list(colour = NULL))) +
  labs(main="Temperature by Height", x="Temperature", y="Density")

与此类似的是我正在努力实现的目标:

Something similar to this is what I'm trying to achieve:

就我而言，年份将被高度取代.

In my case, the years would be substituted by height.

谢谢！！！