Terrain-Viewer ToDos

[jo-chemla]

Quick Fixes

• composite layer for dura into single cog or multiple layers
• no need to patch geomatico a scale and maplibre linear gl instead of nearest
• download button spins
• edit gdal_translate command to include convert encoding to raw altitude DEM
• add note to say where to find gdal, ogeo4w, qgis, conda etc
• bounds of slider should accept only minus, without showing nan to validate
• duplicate source name on byod basemaps. Check with distinct ids if zoom autofit works
• touchscreen max bounds
• min max zoom for source not set on load only on layer switch, and map zoom not set depending on source
• add mapterhorn in inspiration, add suggest new terrain source to mapterhorn or terrainrgb
• add overlay primitives geometry to hide unwanted areas like rc artefacts, or cog mask or no data clip or alpha
• custom stac terrain sources catalog, with footprint, Web-map-link extension or cog, or country isoa3 or regional and ingest stac, or Nextgis-QMS equivalent like terria catalog stac editor stac-manager
• make play360 nuqs state
• TBD: switch theme from jotai storage to nuqs url
• animation bug when closing sidepanel, state kept but cannot pause
• WIP min/max zoom for map and source not working on load, factorize MapSources, terrainrgb reset color function
• look at deckgl-raster and Kyle barron geotiffjs alternative
• set max zoom source on ign wms example
• add for projects or custom source optional fields like geometry features to be shown like masks, or custom home bounds
• make sure there are no better oss geocoders
• edit vanishing point padding when sidebar open

Todo Easy

• Dura dsm and see if can do geomatico fake geo
• Rework the whole animation state, local etc see instructions below: make animation state (pose1, pose2, play, 360) vars nuqs ready. uqs store compact compressed anim state Ways to compress url search query for animation (repeated state complex json object) 47ng/nuqs#1343
• find the right command for DSM with rescale, fakegeo, nodata propagating large pixels overviews, band interp gray, 1 band, alpha. SEE BELOW comment and try to generalize, and add projects
• allow passing project id or terrain or basemap url, in which case terrain and basemap sources and byod should not be shown. Probably only for cog if urls via search params, structured sources for project id
• when nuqs state url shows query pitch = 0.000, then switch to 3D or globe view, with mouse i cannot use the mouse right click to edit pitch, I'm locked in top down view
• auto elevation cannot be set on mobile, nor mac, or 2d Uncaught TypeError: can’t access property “getAllIds”, Ae is undefined
• Allow for Tilejson basemap and simplify TMS, COG, WMS etc pure maplibre or through titiler for basemaps and terrain, maybe factorize url definition and source definition given a source type
• Add a raster-dem WMS float32 raw-elevation geotiff source support maplibre/maplibre-gl-js#7127
• url-shorten with og:media: in social share, add switch to share as intent-url, the terrain-viewer url produced via url-shortener like dubco, passing OG:media as image url posted to imgbb or equivalent
• Harden gpkg loading (in CRS other than 4326) via loadersgl or warn when wrong proj4 crs not 4326 etc, see Issues with polyfills and vite visgl/loaders.gl#2379
• pixel visible in hillshade, might be wrong tileSize for COG or TMS source (maptiler) ? Also can geomatico use terrarium instead of terrainrgb for sub 10cm accuracy? see below referenced issues in maplibre section
• show histogram for terrain for frescoes, eg via titiler /cog/statistics?histogram_bins=100
• export contours vector static file see Add abililty to export via API raw contour lines vector onthegomap/maplibre-contour#432 probably via queryRenderedFeatures map.queryRenderedFeatures({ layers: ['contour-lines'] })

Maplibre features (shaders) & bugfixes threads:

• xy grid resampling bilinear now in the spec, soon in gl-js Implement resampling paint property to raster, hillshade, color relief layers maplibre/maplibre-gl-js#7154
• z quantization terrarium follow Support for terrarium encoding geomatico/maplibre-cog-protocol#25
• Color terrain by normal-derived attributes: slope, aspect, curvature, matcap etc maplibre/maplibre-gl-js#6711
• Maplibre hillshade elevation uint, shows steps vs hypso which does work color gradient when only one meter 10cm bounds range
• Maplibre Overview tiles low res low vfov already exposed here Low resolution tiles loading with low VFOV (<=10°) and high pitch maplibre/maplibre-gl-js#7146
• Local or relative depth vs controllable neighborhood, like diff of gaussian, could even do Relative elevation model via polyline tracing auto or manual
• dub-co feature request cors cross-origin missing and pass thumbnail to POST /links origin domain api [FEAT] CORS support for browser-based API calls dubinc/dub#3502 and [FEAT] Accept base64 image upload for image field on link creation dubinc/dub#3503

Todo long-term

• Other layer types like COPC, 3Dtiles, see plugins from opengeos/maplibre-gl-lidar, or Kanahiro/maplibre-copc-layer and 3Dtiles: Experiment 3Dtiles via official-example based on 3DTilesRendererJS/threejs layer sync or dvt3d/maplibre-three-plugin. These would be considered as completely different 3D sources, in their own xyz-sources panel, with also symbology managed completely differently
• mapbox-gl-elevation to get elevation at cursor or height difference Z+XY
• BYOD STAC sources to assemble multiple COGs or search collection
• try finding/experimenting with WMTS/WMS: sources of true elevation, not precomputed hillshade color-encoded
• probably deprecated, BYOD MosaicJSON (buid mosaicjson with CLI cogeo-mosaic/cli, see archival notice + useful notebook)
• Export footprint and options via watergis/maplibre-gl-export see doc, shows PrintableArea, let user control format, dpi, page orientation, northIcon and marker styles, no scalebar support yet see [FEATURE] Support scale control (and possibly other non-interactive controls) watergis/maplibre-gl-export#383
• eventually add colormaps from rfspace

Todo harder

• Basemap in side split view, or button to tell in which map the settings do apply
• See more, RTI-like, longer-term, here [EPIC] Terrain Elevation Viewer Ameliorations (hillshade etc) historical-satellite#54
• Lens via css clip path with synced dom divs
• check unwanted redraws eventually extract map component from terrain-viewer like control panel is (all nuqs compatible)
• Server-mode ? see below:

Server mode features

• accounts
• saved views
• saved BYOD terrain and basemaps
• share-urls
• custom og:media
• trending/recent board
• custom vector sources

Instructions

Animation rework instructions

Currently, I've got a react-map-gl maplibre app, with control-panel which expose an animation section with CameraButtons. These buttons let me set play360 play/pause, as well as set pose1, pose2, and play/pause animation and scrub via timeline slider. It's not very maintainable, and I want the given requirements :

• animationDuration, loopMode, should be controlled by nuqs url query-params (currently duration is part of animState, it should not otherwise i cannot edit/update duration after setting psoes)
• playing for keyframe animation, and playing360 would also usefully be url-controlled by nuqs
• resolution, fps, render quality should be controlled by atoms with storage
• ideally, pose1, pose2, should live in url as well, probably compressed, eg base64 encode/decode to avoid overflowing url length
• i want 2 modes, one smooth, smoothCamera (also url controlled by nuqs) which would only interpolate camera pose, and one complete, which would also interpolate every other state variable, mostly numericValues, like opacities etc. but using nuqs shallow mode, to not propagate to url
• in addition, there are some local state variables, like elapsed (only elapsed ?)
• if I close and reopen the sidepanel, I want to still be able to clear raf by pausing anim.

Actually want to store deltas only between pose-1 and pose-2, so no-need to compress.

[jo-chemla]

See up-to-date guide over here

Complete DSM & RGB Processing Guide

1. Check current resolution

gdalinfo input.tiff | findstr "Pixel Size"

Shows your actual pixel size (e.g., 0.0005m = 0.5mm for photogrammetry data)

2. Calculate scale factor

• Real GSD: 0.0005m (0.5mm/pixel from photogrammetry)
• Target GSD: 2m/pixel (chosen for web maps)
• Why 2m? Web Mercator at zoom 20 has ~0.15m/pixel resolution at equator. Using 2m/pixel is conservative and works well across zoom levels 15-20. Could as well be eg 20cm or 0.2
• Z-scale factor: 2m ÷ 0.0005m = 4000 (multiply z-elevations by 4000 to compensate xy rescaling)

---

DSM Command (Elevation Data)

gdal_translate -of COG -a_gt 0.01 2.0 0 -0.01 0 -2.0 -a_scale -4000 -a_nodata nan -co BIGTIFF=YES -a_srs EPSG:3857 -co BLOCKSIZE=256 -co TILING_SCHEME=GoogleMapsCompatible -co RESAMPLING=BILINEAR -co OVERVIEW_RESAMPLING=BILINEAR -co COMPRESS=DEFLATE -co PREDICTOR=3 -co OVERVIEWS=IGNORE_EXISTING -co ADD_ALPHA=NO -b 1 -colorinterp_1 gray DuraEuropos_Synagogue_W_0.5mm_DSM.tif
f DuraEuropos_Synagogue_W_0.5mm_DSM_fakegeo-3.cog.tiff

DSM Parameters:

• -of COG - Cloud Optimized GeoTIFF (web-optimized with internal tiling/overviews)
• -a_gt 0 2 0 0 0 -2 - Geotransform: origin (0,0), 2m pixels, no rotation
• -a_scale 4000 - Multiply z-values by 1000 (compensates 2mm→2m pixel scaling)
• -a_nodata nan - Numeric nodata value (RC uses NotANumber as NoData)
• -co BIGTIFF=YES - Handle files >4GB
• -a_srs EPSG:3857 - Web Mercator projection
• -co BLOCKSIZE=256 -co TILING_SCHEME=GoogleMapsCompatible - Recommended by geomatico/maplibre-cog-protocol
• -co RESAMPLING=BILINEAR -co OVERVIEW_RESAMPLING=BILINEAR - Average resampling respects nodata for base tiles and Average for pyramids (prevents nodata spread in overviews)
• -co COMPRESS=DEFLATE -co PREDICTOR=3 - Lossless compression (preserves elevation precision), float elevation requires predictor 3 for continuous elevation data compression
• -co OVERVIEWS=IGNORE_EXISTING -co ADD_ALPHA=NO overwrite overviews, don't add alpha
• -b 1 - Extract only elevation band (drop RGB+Alpha if present)
• -colorinterp_1 gray - Mark as grayscale elevation (required for hillshade to work)

Choice of AVERAGE vs BILINEAR or other for DSM? AVERAGE resampling properly excludes nodata pixels from calculations, preventing nodata from bleeding into valid elevation data in overviews. But results in poorer grid like structure in the data

---

RGB Orthophoto Command

gdal_translate -of COG -a_gt 0.01 2.0 0 -0.01 0 -2.0 -co BIGTIFF=YES -a_srs EPSG:3857 -co BLOCKSIZE
=256 -co TILING_SCHEME=GoogleMapsCompatible -co COMPRESS=JPEG -co QUALITY=95 -co RESAMPLING=BILINEAR -co OVERVIEW_RESAMPLING=BILINEAR -co PREDICTOR=2 -co OVERVIEWS=IGNORE_EXISTING -co ADD_ALPHA=NO DuraEuropos_Synagogue_W_0.5mm_RGB.tiff DuraEuropos_Synagogue_W_0.5mm_RGB_fakegeo.cog.tiff

RGB Parameters:

• -of COG - Cloud Optimized GeoTIFF
• -a_gt 0 2 0 0 0 -2 - Geotransform: origin (0,0), 2m pixels, no rotation
• -co BIGTIFF=YES - Handle files >4GB
• -a_srs EPSG:3857 - Web Mercator projection
• -co BLOCKSIZE=256 -co TILING_SCHEME=GoogleMapsCompatible - Recommended by geomatico/maplibre-cog-protocol
• -co COMPRESS=JPEG -co QUALITY=95 - Lossy compression (better file size for imagery) + JPEG quality
• -co RESAMPLING=BILINEAR - Smooth interpolation for base tiles
• -co OVERVIEW_RESAMPLING=BILINEAR - Smooth interpolation for pyramids (prevents artifacts)
• -co PREDICTOR=2 -co OVERVIEWS=IGNORE_EXISTING -co ADD_ALPHA=NO

No -a_nodata, -colorinterp, or -a_scale - Not needed for RGB imagery

---

RGB with Alpha Channel (RGBA → RGB with mask)

If your orthophoto has transparency (4 bands):

# Be careful, command not tested
# gdal_translate -of COG -co BIGTIFF=YES -co COMPRESS=JPEG -co QUALITY=85 -co RESAMPLING=BILINEAR -co OVERVIEW_RESAMPLING=BILINEAR -b 1 -b 2 -b 3 -mask 4 -a_srs EPSG:3857 -a_gt 0 2 0 0 0 -2 input_orthophoto.tiff output_orthophoto.cog.tiff

Additional RGBA parameters:

• -b 1 -b 2 -b 3 - Select only RGB bands (drop alpha)
• -mask 4 - Convert band 4 (alpha) to internal mask (prevents transparency issues in overviews and allows JPEG compression)

Why drop alpha for JPEG? JPEG doesn't support transparency. Converting alpha to an internal mask preserves transparency information while allowing JPEG compression of the RGB data.

[jo-chemla]

Done

Major features recently added

• weird hq terrain terrarium vs terrainrgb in geomatico
• toggling hillshade off in 2d crashes the app
• nuqs parseAsColor Add support for `parseAsColor` 47ng/nuqs#1342
• hypso slider step could be 100 values always, or closest count that implies decimals that are pow of 10, via log10
• hillshade exaggeration defaults to 0.5, but does not seem to be why basic and multidir appear too bright/burnt
• terrain in 2nd map in split mode is broken
• reorder cpt2js color-ramps discrete vs continuous
• make anim options export atomWithStorage's
• could remembering scroll position in sidepanel be useful ?
• keep xypad for only azimuth and set fixed elevation
• Mobile mode, via transparency non-active sliders
• Result of searching useState in whole repo to set other state vars via jotai atomwithstorage or nuqs url query state : could do so for minimap-minimized
• Terrain not always loading
• Dawing tools not always initializing/appearing
• Export video WIP is laaagggggy solved via MediaBunny, and fallbacks to WebCodecs and MediaRecorder
• Minimap react map gl nice buttons from comments, recover dynamic, zoom offset, bounds footprint, raf pause,
• Share mobile ios and macos not working
• Get elevation to auto set hypso slider bounds, see hypso if does this
• 2d circle control for light position illumination angle and elevation, eventually fixed elevation like slider circular
• reorder panels and default opened panels
• Cam pose 1 to 2 simple traveling
• animation duration (or speed via checkbox switch), a timeline slider, and a checkbox to loop animation, or rather select to loop none, forward or bounce
• Share intent mobile for slack etc
• minimap wip
• TerraDraw, import geojson
• explode
• import kml, wip gpkg
• copy snapshot to clipboard
• share to socials via intent url, text and copy paste to clipboard x bsky threads mastodon etc
• Copy snapshot as well as post to socials with base64 encoded, twitter mastodon bsky maybe expandable button or modal
• Explode Extract contour layer like graticule layer
• Fix Layer ordering via slots layers when editing maplibre style, basemaps etc
• geogrid working and updating correctly
• terradraw opacity
• wip animations like 360, pose1-pose2

Quickfixes

• make top of sidepanel stick to top, useful for mobile
• byod basemap and byod terrain buttons overflow
• no, dont do that eventually add more backdrop to div with slider to have it more prominent
• colorramp tabs could be standard shadcn tabs rather than buttons
• cannot pinch to zoom in 2d on mobile
• make mobile backdrop transmit events so one can pinch to zoom and close sidebar at once.
• Dynamic Viewport Height issue for mobile, minimap control not always appearing when chrome android url bar appears

Wont-do

• Probably not necessary: Mode simplified choose what stays in the sidebar in edit simple mode, useful for single slider or a few checkboxes on mobile in floating panel.
• not very useful, drag and drop import files (into terradraw section?)