在ggplot2 geom_tile图中，是否可以躲避瓷砖的位置？

I'm trying to produce a bar plot where the bars fade vertically according to a third variable, and I'm using geom_tile to enable this. However, I have multiple bars for a given category on the x-axis, and I'd like to dodge their positions to put alike x values together in groups of bars which don't overlap.I'm trying to produce a bar plot where the bars