将点位置添加到R中的3D DEM图

Question

我有一些点位置，包括UTM和Elevation作为数据框我也有一个DEM层。

我已经想出如何使用plot3D中的rgl在3D中绘制DEM。

我还可以使用points3d在3D中绘制点。

我已经能够使用points3d和add=TRUE将它们放在同一个地块中，但是点和DEM远离彼此。

在下面的代码中，我也尝试将其更改为空间数据框，但rgl似乎不喜欢这样。

是否可以将它们与铺设在DEM上的点一起绘制？

我搜索并搜索了一个解决方案。

这是我到目前为止使用的R代码：

> library(raster)
> library(rgdal)
> library(maptools)
> library(rgeos)
> library(lattice)
> library(latticeExtra)
> library(sp)
> library(rasterVis)
> library(rgl)
> 
> # taking data read from a .csv of UTM and elevation values
> 
> Points.Sp <- data.frame(Points=Rawdata$PointName, UTM.N=Rawdata$UTM.N, UTM.W=Rawdata$UTM.W, Elevation=Rawdata$Elevation)
> Points.Sp <- unique(Points.Sp) #weeding out duplicates
> Points.Sp <- Points.Sp[,c(3,2,4)] #getting rid of point names # I realize this looks messy but it gets what I want
> head(Points.Sp)
    UTM.W   UTM.N Elevation
1  275815 3879223      1340
8  274813 3879727      1325
29 275312 3879727      1258
45 275812 3879724      1169
66 276313 3879727      1067
75 276813 3879727      1208
> 
> dem.in <- raster("D:/Thesis/SouthernApps/Coweeta/Coweeta/DEM_30m_wgs84.img") # reading in DEM
> plot(dem.in) # check in 2D # takes a long time very large, need to crop
> 
> dem.crop <- crop(dem.in, c(272000, 282000, 3878000, 3884000))
> plot(dem.crop) # check in 2D, looks good.
> 
> plot3D(dem.crop) # plot in 3D looks like exactly what I want
> 
> points3d(Points.Sp, pch=19, cex=2, col="black", add=TRUE) # adds the points to plot but in wrong place
> 
> #attempting to set a CRS in case this is the problem.
> coordinates(Points.Sp)=c(1,2)
> proj4string(Points.Sp)=CRS("++proj=utm +zone=17") # set CRS
> str(Points.Sp)
Formal class 'SpatialPointsDataFrame' [package "sp"] with 5 slots
  ..@ data       :'data.frame': 71 obs. of  1 variable:
  .. ..$ Elevation: int [1:71] 1340 1325 1258 1169 1067 1208 1256 1089 1031 959 ...
  ..@ coords.nrs : num [1:2] 1 2
  ..@ coords     : num [1:71, 1:2] 275815 274813 275312 275812 276313 ...
  .. ..- attr(*, "dimnames")=List of 2
  .. .. ..$ : chr [1:71] "1" "8" "29" "45" ...
  .. .. ..$ : chr [1:2] "UTM.W" "UTM.N"
  ..@ bbox       : num [1:2, 1:2] 274309 3878440 279876 3883732
  .. ..- attr(*, "dimnames")=List of 2
  .. .. ..$ : chr [1:2] "UTM.W" "UTM.N"
  .. .. ..$ : chr [1:2] "min" "max"
  ..@ proj4string:Formal class 'CRS' [package "sp"] with 1 slot
  .. .. ..@ projargs: chr "+proj=utm +zone=17 +ellps=WGS84"
> 
> # trying this a different way after setting CRS
> x <- Points.Sp@coords[1:71,1]
> y <- Points.Sp@coords[1:71,2]
> z <- Points.Sp@data$Elevation
> m <- data.frame(x=x,y=y,z=z)
> 
> plot3D(dem.crop) #again, plot in 3D looks like exactly what I want
> points3d(m, pch=19, cex=2, col="black", add=TRUE) # still adds the points to plot but in wrong place

此代码重现了该问题。

## define a Raster object
data(volcano)
r <- raster(volcano)
extent(r) <- c(0, 610, 0, 870)

## extract sample points
xy <- sampleRandom(r1, 100, xy = TRUE)     
r1<-data.frame(x=seq(0, 500, length=(71)), y=seq(0, 500, length=(71)), z=seq(0,500, length=(71)))

## display them
plot3D(r, adjust = FALSE)

points3d(r1, add=TRUE)

Answer 1

如帮助页面中所述，x轴和y轴均使用z值进行调整。您可以使用adjust = FALSE禁用此默认设置：

library(rgl)
library(rasterVis)

## define a Raster object
data(volcano)
r <- raster(volcano)
extent(r) <- c(0, 610, 0, 870)

## extract sample points
xy <- sampleRandom(r, 100, xy = TRUE)     

## display them
plot3D(r, adjust = FALSE)
points3d(xy)

Answer 2

## define a Raster object
data(volcano)
r <- raster(volcano)
extent(r) <- c(0, 610, 0, 870)

## extract sample points
xy <- sampleRandom(r1, 100, xy = TRUE)     

#must extract the data from the raster and recombine with the xy data.
#I don't know why this is different than simply using the raw values but it
#provides the desired effect. 
  
r1<-data.frame(x=seq(0, 500, length=(71)), y=seq(0, 500, length=(71)))
z<-extract(r, r1)
r1$z<-z
## display them
plot3D(r, adjust = FALSE)

points3d(r1, add=TRUE)
  
#points now lie flat on 3d image.

Points flush to 3d Image

Image for original problem