Alpha from stat_summary_2d ignored

ggplotly does not carry over the alpha level for stat_summary_2d. Seems like it may be similar to the same issue that occurred with points in a previous version.

This isn't as obvious in the reproducible example, but for regions where the map isn't just water, and the locations are more dense, having the alpha allows for a visible basemap.

fiji <-  get_googlemap("Fiji", zoom = 5, maptype = "roadmap", color = "bw", size = c(640, 480), scale = 2)

ggplotly({
  ggmap(fiji, extent = "device") + 
  stat_summary_2d(data = quakes, aes(x = long, y = lat, z = mag), alpha = .55 , fun = mean, bins = 100) +
  scale_fill_gradient(name = "Fullness", low = "green", high = "red")
  }, tooltip = "fill"
)

ggplot2 output:

plotly output:

issue内の再現可能なR例から始め、ggplot2とplotlyの出力を比較し、stat_summary_2dとそのalpha設定に焦点を当てます。このレイヤーの変換経路を追跡し、plotly出力がベースマップ上で要求された透明度を維持していることを確認して結果を検証します。