Kyle/elevation example - #647
Draft
kylebarron wants to merge 2 commits into
Draft
Conversation
Designs a 2D example that streams USGS 3DEP 1-meter lidar DEMs from the public National Map bucket and computes hillshade, slope, and tinted relief on the GPU, with an interactive sun angle. Hillshade is the first convolutional shader module in the project, which collides with per-tile independent fetching: the 3x3 Horn kernel has no neighbors at tile edges, producing a visible seam grid. The spec resolves this in application code with a one-texel halo — a (tileWidth + 2) square texture — backed by a shared decoded-tile cache, so the 8 neighbors are decoded once and shared across up to 9 halo assemblies rather than refetched per tile. Verified against the bucket: CORS is open with working range GETs, the cells are valid COGs with overviews, and internal tile size (256 vs 512), nodata, and UTM zone all vary across vintages, so none may be hardcoded. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
This is a vibe-coded example for rendering a terrain COG. This came from discussions at FOSS4G with @hobu.
This is a draft because I haven't read and corrected the initial claude output yet.
In particular, the hardest problem is that, as a convolutional shader, we need to fill in edge pixels from neighboring tiles, lest we want to have seams visible across tiles. Claude implemented a solution but I haven't read it yet.
Designs a 2D example that streams USGS 3DEP 1-meter lidar DEMs from the
public National Map bucket and computes hillshade, slope, and tinted
relief on the GPU, with an interactive sun angle.
Hillshade is the first convolutional shader module in the project, which
collides with per-tile independent fetching: the 3x3 Horn kernel has no
neighbors at tile edges, producing a visible seam grid. The spec resolves
this in application code with a one-texel halo — a (tileWidth + 2) square
texture — backed by a shared decoded-tile cache, so the 8 neighbors are
decoded once and shared across up to 9 halo assemblies rather than
refetched per tile.
Co-Authored-By: Claude Opus 5 (1M context) noreply@anthropic.com