在rgl圖中以互動方式識別3D物件

我想在rgl繪圖中識別 3d 圓柱體以獲得最近/選定圓柱體的一個屬性。我嘗試使用標簽來簡單地拼出屬性，但我處理的資料超過 10.000 個圓柱體。因此，它變得如此擁擠以至于標簽不可讀并且需要很長時間才能呈現。

我試圖了解檔案，rgl我想我的問題的解決方案是手動選擇圖中的圓柱體。我相信這個功能selectpoints3d()可能是要走的路。我相信它會回傳繪制矩形內的所有頂點，但我不知道如何回傳圓柱資料？我可以計算出哪個圓柱最接近所選頂點的平均值，但這似乎是一種“快速而骯臟”的作業方式。

有更好的方法嗎？我注意到value=FALSE僅獲取索引的論點，但我不知道如何回傳氣缸。

這是一些虛擬資料和我的代碼：

# dummy data
cylinder <- data.frame(
  start_X = rep(1:3, 2)*2,
  start_Y = rep(1:2, each = 3)*2,
  start_Z = 0,
  end_X = rep(1:3, 2)*2   round(runif(6, -1, 1), 2),
  end_Y = rep(1:2, each = 3)*2   round(runif(6, -1, 1), 2),
  end_Z = 0.5,
  radius = 0.25,
  attribute = sample(letters[1:6], 6)
)

# calculate centers
cylinder$center_X <- rowMeans(cylinder[,c("start_X", "end_X")])
cylinder$center_Y <- rowMeans(cylinder[,c("start_Y", "end_Y")])
cylinder$center_Z <- rowMeans(cylinder[,c("start_Z", "end_Z")])

# create cylinders
cylinder_list <- list()
for (i in 1:nrow(cylinder)) {
  cylinder_list[[i]] <- cylinder3d(
    center = cbind(
      c(cylinder$start_X[i], cylinder$end_X[i]),
      c(cylinder$start_Y[i], cylinder$end_Y[i]),
      c(cylinder$start_Z[i], cylinder$end_Z[i])),
    radius = cylinder$radius[i],
    closed = -2)
}

# plot cylinders
open3d()
par3d()
shade3d(shapelist3d(cylinder_list, plot = FALSE), col = "blue")
text3d(cylinder$center_X 0.5, cylinder$center_Y 0.5, cylinder$center_Z 0.5, cylinder$attribute, color="red")

# get attribute
nearby <- selectpoints3d(value=TRUE, button = "right")
nearby <- colMeans(nearby)
cylinder$dist <- sqrt(
  (nearby["x"]-cylinder$center_X)**2  
  (nearby["y"]-cylinder$center_Y)**2  
  (nearby["z"]-cylinder$center_Z)**2)
cylinder$attribute[which.min(cylinder$dist)]

uj5u.com熱心網友回復：

如果你打電話selectpoints3d(value = FALSE)，你會得到兩列。第一列是找到的物件的 ID。您的氣缸每個都有兩個 id。標記圓柱體的一種方法是使用“標簽”。例如，您的代碼的這種修改：

# dummy data
cylinder <- data.frame(
  start_X = rep(1:3, 2)*2,
  start_Y = rep(1:2, each = 3)*2,
  start_Z = 0,
  end_X = rep(1:3, 2)*2   round(runif(6, -1, 1), 2),
  end_Y = rep(1:2, each = 3)*2   round(runif(6, -1, 1), 2),
  end_Z = 0.5,
  radius = 0.25,
  attribute = sample(letters[1:6], 6)
)

# calculate centers
cylinder$center_X <- rowMeans(cylinder[,c("start_X", "end_X")])
cylinder$center_Y <- rowMeans(cylinder[,c("start_Y", "end_Y")])
cylinder$center_Z <- rowMeans(cylinder[,c("start_Z", "end_Z")])

# create cylinders
cylinder_list <- list()
for (i in 1:nrow(cylinder)) {
  cylinder_list[[i]] <- cylinder3d(
    center = cbind(
      c(cylinder$start_X[i], cylinder$end_X[i]),
      c(cylinder$start_Y[i], cylinder$end_Y[i]),
      c(cylinder$start_Z[i], cylinder$end_Z[i])),
    radius = cylinder$radius[i],
    closed = -2)

  # Add tag here:

  cylinder_list[[i]]$material$tag <- cylinder$attribute[i]
}

# plot cylinders
open3d()
par3d()
shade3d(shapelist3d(cylinder_list, plot = FALSE), col = "blue")
text3d(cylinder$center_X 0.5, cylinder$center_Y 0.5, cylinder$center_Z 0.5, cylinder$attribute, color="red")

# Don't get values, get the ids

nearby <- selectpoints3d(value=FALSE, button = "right", closest = FALSE)
ids <- nearby[, "id"]

# Convert them to tags.  If you select one of the labels, you'll get
# a blank in the list of tags, because we didn't tag the text.

unique(tagged3d(id = ids))

當我嘗試這個時，我發現使用closest = TRUEinselectpoints3d似乎得到了太多的 id；那里可能有一個錯誤。

標籤：r 3d rgl

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