Awesome
dem-tiler
Work in progress
A fork of cogeo-mosaic-tiler
to serve elevation products
on demand from a mosaic of Cloud-Optimized GeoTIFF elevation data.
Overview
Input Formats
AWS Terrain Tiles
AWS Terrain Tiles is an open dataset on S3 with global elevation data in the Web Mercator projection. This makes it easy to use as an input format, and is the fastest input format available.
COG MosaicJSON
MosaicJSON of Cloud-Optimized GeoTIFF (COG) files.
The USGS has recently put almost all their elevation files in
COG format. Additionally, the USGS plans to complete 1-meter DEMs of the entire
continental U.S. by the end of 2023, and all these files are created in COG
format. See usgs-dem-mosaic
(WIP) for instructions on
creating a MosaicJSON of USGS COGs.
Output Formats
Terrain RGB
Encodes raw elevation values into a PNG, using the red, green, and blue channels
for a high bit depth. The terrarium
encoding has
3-millimeter precision and the mapbox
encoding (not
yet implemented) has 10-centimeter precision.
If you plan to use AWS terrain tiles as the input format, and don't plan to add a buffer to the tile, there's no reason to use this package, and you should access the public tiles directly.
Extra buffer
Can export PNG images of size 258x258 pixels or 518x518px, i.e. an extra 1-pixel border around the normal 256 or 512-pixel tile. This is helpful for client-side slope computations, where you need a 1 pixel border around the tile.
Contours
Uses gdal_contour
and tippecanoe
to provide
Mapbox Vector Tiles of elevation contours on demand. Contours can be generated
at an arbitrary interval, and can be shown in either meters or feet.
Quantized Mesh
Quantized Mesh is a file format for terrain meshes, ideal
for transport to the browser for 3D terrain rendering. This output format uses
pymartini
for fast mesh generation from a raster heightmap, and
then quantized-mesh-encoder
to encode the mesh.
Deploy
Package Lambda
Create the AWS Lambda deployment package
make package
Deploy to AWS
This project uses Serverless to manage deploy on AWS.
If you plan to use AWS Terrain Tiles as input data, you should deploy to
us-east-1
for minimal latency. If you plan to use USGS COGs as input data, you
should deploy to us-west-2
for minimal latency. If you plan to use both, it
may be wise to deploy to both regions and switch between them depending on the
data source for the request.
# Install and Configure serverless (https://serverless.com/framework/docs/providers/aws/guide/credentials/)
$ npm install serverless -g
$ sls deploy --region us-east-1 --bucket a-bucket-where-you-store-data