Add distance measurement and rescaling feature for 3DGS #246
Conversation
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
- Add PlyWriter class to export PackedSplats to standard PLY format - Add distance-rescale example with interactive point selection - Support ray-based point selection with visible ray lines - Allow dragging points along ray lines to adjust depth - Implement model rescaling based on measured vs desired distance - Export rescaled models as PLY files 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Add PlyWriter class to export PackedSplats to standard PLY format - Add distance-rescale example with interactive point selection - Support ray-based point selection with visible ray lines - Allow dragging points along ray lines to adjust depth - Implement model rescaling based on measured vs desired distance - Export rescaled models as PLY files 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Switch from SparkControls to OrbitControls for reliability - Auto-center camera on model using getBoundingBox - Dynamic marker/ray sizing based on model dimensions - Change newDistance to text input (was slider limited to 0.001-100) - Add proper rotation.x = Math.PI for PLY orientation - Improve error handling and add debug logging 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Increase marker radius from 0.5% to 2% of model size - Add white ring outline around markers for contrast - Ring billboards to always face camera - Markers now visible against any background 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Remove overly restrictive minT clamping (was markerRadius*5, now 0.01) - Allow movement beyond visible ray line (maxT = rayLineLength * 2) - Keep current point when rays are parallel instead of jumping - Pass current point to closestPointOnRay for better fallback behavior 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
The markers are now THREE.Group (sphere + ring), so intersectObjects returns child meshes, not the group. Walk up the parent chain to find which marker group was actually hit. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Remove world-space marker sizing (markerRadius) - Add MARKER_SCREEN_SIZE constant (3% of screen height) - Scale markers dynamically based on camera distance in render loop - Markers now stay same visual size when zooming in/out 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Add explicit else-if check for point2 in drag handler for safety - Add disposeObject helper to properly dispose Three.js geometries/materials - Prevent memory leaks when resetting selection 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Add 15 comprehensive unit tests for PlyWriter: - Constructor with default/custom options - PLY header generation validation - Binary data size verification - Position, scale, quaternion encoding - Log scale encoding with zero fallback - Sigmoid opacity encoding with edge case clamping - Color DC coefficient encoding - Empty splats handling - Big endian format support - Multiple splats ordering - Fix bug: replace() only replaced first underscore in format string Changed to replaceAll() for proper "binary little endian" output 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
PLY reader expects "binary_little_endian" with underscores, not spaces. This was causing exported PLY files to fail to load (appearing all black). 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
Contributor
|
Thanks. I'm not sure if this should be a core spark feature or leave it as a 3rd party library / component. It seems too specific |
Author
|
Thank you for your response. I think this feature will be the reason to select spark as a default Gaussian splatting viewer, because there is no viewer in the world which can measure and rescale the model. Currently only reall3D viewer has a distance measurement function, but it can only select 2 points in 2D space, cannot rescale nor save,and it is totally in Chinese. So if this is approved, spark is the only one Gaussian splatting viewer in the world, which can measure and insert a real scale into the created Gaussian spot model. |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
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.
Objective
Add measuring 2 point distance function. And also add rescale, save new ply function.
Test result
I added these functions to example as below.
This is the new function test movie.
Screencast from 2025-12-25 17-05-38.webm
Summary
This PR adds a new feature for measuring distances between two points on a Gaussian splat model and rescaling the model based on a known distance.
New Features
New Files
src/PlyWriter.ts- PLY export library for PackedSplats dataexamples/distance-rescale/- Interactive example demonstrating the featuretest/PlyWriter.test.ts- Unit tests for PlyWriter (15 test cases)Key Implementation Details
Tests Added
Bug Fixes
replace()→replaceAll()for proper "binary little endian" output🤖 Generated with Claude Code