我试图通过覆盖更新（更高细节）卫星图像（我从 { leaflet} 包中获得）来改善 Rayshader 的外观，但覆盖与 3D 渲染不匹配。
理想情况下，我正在寻找可以获取全球卫星图像的开源解决方案。如果您找到我感兴趣的地区（夏威夷）的更详细数据，则可获得奖励积分。
geoviz使用 { } 和 { } 的一种方法使用rayshader该slippy_overlay()函数从Mapbox（卫星、mapbox-streets-v8、mapbox-terrain-v2、mapbox-traffic-v1、terrain-rgb、mapbox-incidents- v1 ) 或雄蕊。虽然我发现mapbox-terrain-v2是最好的，但它仍然缺乏我想要的细节。因为它需要为 mapbox 设置一个 API，所以我只使用下面的stamen/watercolor：
library(geoviz)
library(rayshader)
### Maui
lat = 20.785700
lon = -156.259204
square_km = 22
max_tiles = 10
dem <- mapzen_dem(lat, lon, square_km, max_tiles)
elev_matrix = matrix(
raster::extract(dem, raster::extent(dem), buffer=1000),
nrow = ncol(dem),
ncol = nrow(dem)
)
ambmat <- ambient_shade(elev_matrix, zscale = 30)
raymat <- ray_shade(elev_matrix, zscale = 30, lambert = TRUE)
watermap <- detect_water(elev_matrix)
overlay_img <-
slippy_overlay(dem,
image_source = "stamen",
image_type = "watercolor",
png_opacity = 0.3,
max_tiles = max_tiles)
elev_matrix %>%
sphere_shade(sunangle = 270, texture = "imhof4") %>%
add_water(detect_water(elev_matrix), color="imhof4") %>%
add_shadow(ray_shade(elev_matrix,zscale=3,maxsearch = 300),0.5) %>%
add_shadow(ambmat,0.5) %>%
add_overlay(overlay_img) %>%
plot_3d(elev_matrix,
solid = T,
water = T,
waterdepth = 0,
wateralpha = 0.5,
watercolor = "lightblue",
waterlinecolor = "white",
waterlinealpha = 0.5,
zscale= raster_zscale(dem) / 3,
fov=0,theta=135,zoom=0.75,phi=45, windowsize = c(1000,800))
我正在尝试调整Will Bishop的工作流程以获取leaflet包的覆盖，但结果非常奇怪。Will 的方法有点不同，因为它从 USGS 获取高程数据，它没有我必须的海湾高程 - 所以我使用了geoviz
library(leaflet)
# define bounding box with longitude/latitude coordinates
bbox <- list(
p1 = list(long = -156.8037, lat = 20.29737),
p2 = list(long = -155.7351, lat = 21.29577)
)
leaflet() %>%
addTiles() %>%
addRectangles(
lng1 = bbox$p1$long, lat1 = bbox$p1$lat,
lng2 = bbox$p2$long, lat2 = bbox$p2$lat,
fillColor = "transparent"
) %>%
fitBounds(
lng1 = bbox$p1$long, lat1 = bbox$p1$lat,
lng2 = bbox$p2$long, lat2 = bbox$p2$lat,
)
我的山体阴影面积是geoviz多少？
dim(dem)
780 780 1
好的，因此需要叠加图像，780 x 780因此我修改了辅助函数以下载带有World_Imagery基本地图的叠加层：
define_image_size <- function(bbox, major_dim = 780) {
# calculate aspect ration (width/height) from lat/long bounding box
aspect_ratio <- abs((bbox$p1$long - bbox$p2$long) / (bbox$p1$lat - bbox$p2$lat))
# define dimensions
img_width <- ifelse(aspect_ratio > 1, major_dim, major_dim*aspect_ratio) %>% round()
img_height <- ifelse(aspect_ratio < 1, major_dim, major_dim/aspect_ratio) %>% round()
size_str <- paste(img_width, img_height, sep = ",")
list(height = img_height, width = img_width, size = size_str)
}
get_arcgis_map_image <- function(bbox, map_type = "World_Imagery", file = NULL,
width = 780, height = 780, sr_bbox = 4326) {
require(httr)
require(glue)
require(jsonlite)
url <- parse_url("https://utility.arcgisonline.com/arcgis/rest/services/Utilities/PrintingTools/GPServer/Export%20Web%20Map%20Task/execute")
# define JSON query parameter
web_map_param <- list(
baseMap = list(
baseMapLayers = list(
list(url = jsonlite::unbox(glue("https://services.arcgisonline.com/ArcGIS/rest/services/{map_type}/MapServer",
map_type = map_type)))
)
),
exportOptions = list(
outputSize = c(width, height)
),
mapOptions = list(
extent = list(
spatialReference = list(wkid = jsonlite::unbox(sr_bbox)),
xmax = jsonlite::unbox(max(bbox$p1$long, bbox$p2$long)),
xmin = jsonlite::unbox(min(bbox$p1$long, bbox$p2$long)),
ymax = jsonlite::unbox(max(bbox$p1$lat, bbox$p2$lat)),
ymin = jsonlite::unbox(min(bbox$p1$lat, bbox$p2$lat))
)
)
)
res <- GET(
url,
query = list(
f = "json",
Format = "PNG32",
Layout_Template = "MAP_ONLY",
Web_Map_as_JSON = jsonlite::toJSON(web_map_param))
)
if (status_code(res) == 200) {
body <- content(res, type = "application/json")
message(jsonlite::toJSON(body, auto_unbox = TRUE, pretty = TRUE))
if (is.null(file))
file <- tempfile("overlay_img", fileext = ".png")
img_res <- GET(body$results[[1]]$value$url)
img_bin <- content(img_res, "raw")
writeBin(img_bin, file)
message(paste("image saved to file:", file))
} else {
message(res)
}
invisible(file)
}
现在下载文件，然后加载它
image_size <- define_image_size(bbox, major_dim = 780)
# fetch overlay image
overlay_file <- "maui_overlay.png"
get_arcgis_map_image(bbox, map_type = "World_Imagery", file = overlay_file,
# width = image_size$width, height = image_size$height,
sr_bbox = 4326)
overlay_img <- png::readPNG("maui_overlay.png")
好的，让我们制作情节
elev_matrix %>%
sphere_shade(sunangle = 270, texture = "imhof4") %>%
add_water(detect_water(elev_matrix), color="imhof4") %>%
add_shadow(ray_shade(elev_matrix,zscale=3,maxsearch = 300),0.5) %>%
add_shadow(ambmat,0.5) %>%
add_overlay(overlay_img, alphacolor = 1) %>%
plot_3d(elev_matrix,
solid = T,
water = T,
waterdepth = 0,
wateralpha = 0.5,
watercolor = "lightblue",
waterlinecolor = "white",
waterlinealpha = 0.5,
zscale= raster_zscale(dem) / 3,
fov=0,theta=135,zoom=0.75,phi=45, windowsize = c(1000,800))
如您所见，叠加图像旋转到山体阴影。
现在我也意识到，当您尝试显示深海矩阵数据时，使用边界框方法获取卫星并不理想。以某种方式以编程方式对该叠加层进行子集化是理想的，但一旦我弄清楚如何旋转叠加层，我可能最终会使用inkscape 。
我尝试使用 { magick} 的image_rotate()功能无济于事：
library(magick)
maui <- magick::image_read("maui_overlay.png")
image_rotate(maui, 30) # -> maui_30
# image_write(maui_30, path = "maui_overlay_30.png", format = "png")
但magick改变了尺寸：
# A tibble: 1 x 7
format width height colorspace matte filesize density
<chr> <int> <int> <chr> <lgl> <int> <chr>
1 PNG 1068 1068 sRGB TRUE 0 38x38
并且会给出一个错误rayshader：
overlay_img <- png::readPNG("maui_overlay_30.png")
elev_matrix %>%
sphere_shade(sunangle = 270, texture = "imhof4") %>%
add_water(detect_water(elev_matrix), color="imhof4") %>%
add_shadow(ray_shade(elev_matrix,zscale=3,maxsearch = 300),0.5) %>%
add_shadow(ambmat,0.5) %>%
add_overlay(overlay_img, alphacolor = 1) %>%
plot_3d(elev_matrix,
solid = T,
water = T,
waterdepth = 0,
wateralpha = 0.5,
watercolor = "lightblue",
waterlinecolor = "white",
waterlinealpha = 0.5,
zscale= raster_zscale(dem) / 3,
fov=0,theta=135,zoom=0.75,phi=45, windowsize = c(1000,800))
add_overlay(., overlay_img, alpha = 0.8) 中的错误：参数 3 匹配多个形式参数