facebookresearch/momentum
Mar 2025 – Mar 2026
11 Months active
Languages Used
C++PythonYAMLJSON
Technical Skills
Algorithm OptimizationC++ DevelopmentDebuggingMultithreadingPerformance OptimizationSoftware Testing
Carsten Stoll
PROFILE
Carsten Stoll
Over eleven months, contributed to the facebookresearch/momentum repository by building and refining core systems for 3D animation, geometry processing, and asset pipelines. Developed features such as mesh self-intersection detection, joint distance constraints for character animation, and robust calibration workflows, applying C++ and Python with a focus on numerical stability and cross-language integration. Led major codebase refactors to improve maintainability, modularized error functions, and enhanced test coverage. Addressed asset pipeline reliability by implementing metadata systems and improving GLTF/FBX handling. Demonstrated strengths in algorithm optimization, multithreading, and software architecture, consistently delivering production-ready solutions and improving developer usability through thoughtful API enhancements.
Overall Statistics
Feature vs Bugs
69%Features
Repository Contributions
49Total
Bugs
9
Commits
49
Features
20
Lines of code
20,580
Activity Months11
Your Network
3153 peopleSame Organization
@meta.com3078
Peter RongMember
Zain RizviMember
Aaditya NairMember
Aahan AggarwalMember
Aliaksei AndreyeuMember
Arjun ChaturvediMember
Aaron FarberMember
Aaron PollackMember
Aaryaman SagarMember
Shared Repositories
75
Andreas ForsterMember
Alec DutchMember
Filippo ArcaduMember
Brian WaltersMember
Bogdan MorosanuMember
Bowie ChenMember
Chris TwiggMember
Clark KangMember
Daniel RodríguezMember
Work History
March 2026
11 Commits • 1 Features
Mar 1, 2026March 2026 monthly summary for facebookresearch/momentum. Delivered a comprehensive Momentum Core Refactor and Maintenance to improve code maintainability, readability, and collaboration readiness across modules, including test reorganization, autograd separation for IK, IO/rendering restructuring, parameter JSON utilities simplification, and namespace modernization. This work stabilizes the foundation for future feature velocity and reduces maintenance risk. A targeted rendering bug fix in rasterizeMesh corrected texture coordinate binding, improving rendering correctness and user-facing visuals.
11 Commits • 1 Features
Mar 1, 2026March 2026 monthly summary for facebookresearch/momentum. Delivered a comprehensive Momentum Core Refactor and Maintenance to improve code maintainability, readability, and collaboration readiness across modules, including test reorganization, autograd separation for IK, IO/rendering restructuring, parameter JSON utilities simplification, and namespace modernization. This work stabilizes the foundation for future feature velocity and reduces maintenance risk. A targeted rendering bug fix in rasterizeMesh corrected texture coordinate binding, improving rendering correctness and user-facing visuals.
March 2026
February 2026
2 Commits • 1 Features
Feb 1, 2026February 2026 performance summary for facebookresearch/momentum: Delivered NumPy support for core utilities by implementing NumPy-based versions of skel_state.py and quaternion utilities, mirroring PyTorch functionality to broaden NumPy compatibility and performance. This work, captured in two focused commits with code reviews, lays the groundwork for broader NumPy adoption and easier integration in NumPy-centric workflows. No major bug fixes this month; the primary impact is parity, accessibility, and groundwork for future enhancements.
February 2026
2 Commits • 1 Features
Feb 1, 2026February 2026 performance summary for facebookresearch/momentum: Delivered NumPy support for core utilities by implementing NumPy-based versions of skel_state.py and quaternion utilities, mirroring PyTorch functionality to broaden NumPy compatibility and performance. This work, captured in two focused commits with code reviews, lays the groundwork for broader NumPy adoption and easier integration in NumPy-centric workflows. No major bug fixes this month; the primary impact is parity, accessibility, and groundwork for future enhancements.
January 2026
2 Commits • 1 Features
Jan 1, 2026January 2026 (Momentum repo) delivered a focused set of asset-quality and loader-robustness improvements to strengthen asset tracking, analytics, and pipeline reliability. Implemented a Character Metadata System to support unique asset identification and processing metadata, and hardened GLTF loading with safeguards around skeletons, meshes, and collision geometry. These changes reduce import errors, improve downstream decision-making, and demonstrate strong cross-domain collaboration and code quality.
2 Commits • 1 Features
Jan 1, 2026January 2026 (Momentum repo) delivered a focused set of asset-quality and loader-robustness improvements to strengthen asset tracking, analytics, and pipeline reliability. Implemented a Character Metadata System to support unique asset identification and processing metadata, and hardened GLTF loading with safeguards around skeletons, meshes, and collision geometry. These changes reduce import errors, improve downstream decision-making, and demonstrate strong cross-domain collaboration and code quality.
January 2026
December 2025
5 Commits • 1 Features
Dec 1, 2025December 2025 monthly summary for facebookresearch/momentum. Delivered end-to-end enhancements to blendshape naming UX and GLTF integration, and strengthened Python bindings, improving asset pipelines and cross-tool interoperability.
December 2025
5 Commits • 1 Features
Dec 1, 2025December 2025 monthly summary for facebookresearch/momentum. Delivered end-to-end enhancements to blendshape naming UX and GLTF integration, and strengthened Python bindings, improving asset pipelines and cross-tool interoperability.
November 2025
5 Commits • 2 Features
Nov 1, 2025November 2025: Focused delivery on animation realism and asset pipeline reliability in facebookresearch/momentum. Key features include a Joint Distance Constraint System for Character Animation and enhanced FBX BlendShape Import/Export with proper naming, underpinned by PR-driven changes and cross-team reviews. Delivered fixes to blendshape handling to improve correctness and maintainability of the asset pipeline.
5 Commits • 2 Features
Nov 1, 2025November 2025: Focused delivery on animation realism and asset pipeline reliability in facebookresearch/momentum. Key features include a Joint Distance Constraint System for Character Animation and enhanced FBX BlendShape Import/Export with proper naming, underpinned by PR-driven changes and cross-team reviews. Delivered fixes to blendshape handling to improve correctness and maintainability of the asset pipeline.
November 2025
October 2025
5 Commits • 3 Features
Oct 1, 2025Month: 2025-10 momentum contributions focused on delivering reliability in asset loading, robustness in the solver, and enriched animation capabilities. Delivered key features with accompanying tests and resolved a critical error-calc bug affecting geometry processing.
October 2025
5 Commits • 3 Features
Oct 1, 2025Month: 2025-10 momentum contributions focused on delivering reliability in asset loading, robustness in the solver, and enriched animation capabilities. Delivered key features with accompanying tests and resolved a critical error-calc bug affecting geometry processing.
August 2025
2 Commits • 1 Features
Aug 1, 20252025-08 monthly summary for facebookresearch/momentum: Delivered improvements to constraint management in Solver2 and fixed GLB identity handling to ensure consistent identity mapping and loading. These changes improve stability and predictability of motion vector processing, enhance solver state management, and reduce risk of incorrect scaling parameter application when motion data is absent.
2 Commits • 1 Features
Aug 1, 20252025-08 monthly summary for facebookresearch/momentum: Delivered improvements to constraint management in Solver2 and fixed GLB identity handling to ensure consistent identity mapping and loading. These changes improve stability and predictability of motion vector processing, enhance solver state management, and reduce risk of incorrect scaling parameter application when motion data is absent.
August 2025
July 2025
5 Commits • 3 Features
Jul 1, 2025July 2025 monthly summary for facebookresearch/momentum focused on delivering impactful calibration improvements, API enhancements, and developer usability gains. The work emphasizes business value through faster, more reliable motion calibration and easier maintenance of geometric representations and error-function workflows.
July 2025
5 Commits • 3 Features
Jul 1, 2025July 2025 monthly summary for facebookresearch/momentum focused on delivering impactful calibration improvements, API enhancements, and developer usability gains. The work emphasizes business value through faster, more reliable motion calibration and easier maintenance of geometric representations and error-function workflows.
May 2025
5 Commits • 3 Features
May 1, 2025May 2025 monthly summary — facebookresearch/momentum Key features delivered: - Mesh Self-Intersection Detection: implemented brute-force and BVH-based detection with a Python wrapper and comprehensive unit tests to validate intersecting face pairs from Python. Commits: bb974a0d18428e3bca45fb557802d331e7e60de4; dc7940d41c5de6ca3b6adc04e40c742b12069074. - Marker Tracker Calibration Enhancements: reintroduced pose priors and first-frame floor constraints in the marker solver, and added a greedy frame sampling method to capture frames with maximal pose variance. Commits: 736c8b9dcc2f98bc4038944a8fecfec795d739a5; a442b1efff3790185ce36ff9e09c67f677796f61. - Vertex Projection Error Function for Inverse Kinematics in pymomentum: introduced a vertex projection error function with C++/Python implementations, solver integration, and tests. Commit: 59406a4e087fe04a71f9ac6eca3077c0af335c14. Major bugs fixed: - No separate bug-fix-only commits identified for May 2025; bug-fixes were incorporated within feature work and associated tests, contributing to overall reliability improvements. Overall impact and accomplishments: - Strengthened geometry processing reliability and validation through robust mesh intersection testing. - Enhanced calibration workflows with pose priors, floor constraints, and variance-maximizing frame sampling, reducing calibration time while increasing accuracy. - Improved inverse kinematics accuracy in pymomentum via a dedicated vertex projection error function, enabling more realistic pose estimation. Technologies/skills demonstrated: - C++ and Python developer tooling, cross-language bindings, BVH-based acceleration, solver integration, and test-driven development.
5 Commits • 3 Features
May 1, 2025May 2025 monthly summary — facebookresearch/momentum Key features delivered: - Mesh Self-Intersection Detection: implemented brute-force and BVH-based detection with a Python wrapper and comprehensive unit tests to validate intersecting face pairs from Python. Commits: bb974a0d18428e3bca45fb557802d331e7e60de4; dc7940d41c5de6ca3b6adc04e40c742b12069074. - Marker Tracker Calibration Enhancements: reintroduced pose priors and first-frame floor constraints in the marker solver, and added a greedy frame sampling method to capture frames with maximal pose variance. Commits: 736c8b9dcc2f98bc4038944a8fecfec795d739a5; a442b1efff3790185ce36ff9e09c67f677796f61. - Vertex Projection Error Function for Inverse Kinematics in pymomentum: introduced a vertex projection error function with C++/Python implementations, solver integration, and tests. Commit: 59406a4e087fe04a71f9ac6eca3077c0af335c14. Major bugs fixed: - No separate bug-fix-only commits identified for May 2025; bug-fixes were incorporated within feature work and associated tests, contributing to overall reliability improvements. Overall impact and accomplishments: - Strengthened geometry processing reliability and validation through robust mesh intersection testing. - Enhanced calibration workflows with pose priors, floor constraints, and variance-maximizing frame sampling, reducing calibration time while increasing accuracy. - Improved inverse kinematics accuracy in pymomentum via a dedicated vertex projection error function, enabling more realistic pose estimation. Technologies/skills demonstrated: - C++ and Python developer tooling, cross-language bindings, BVH-based acceleration, solver integration, and test-driven development.
May 2025
April 2025
5 Commits • 3 Features
Apr 1, 2025April 2025: In facebookresearch/momentum, delivered four focused improvements to robustness, accuracy, and developer productivity. 1) Vertex Error Function Refinement: refactored to separate serial and parallel execution paths, added a dedicated parallel test to ensure accurate error evaluation, improving reliability of vertex error calculations. 2) Vertex Projection Error Function: introduced 2D losses for skinned vertices, plus skinning weight iterator and tests; updated error thresholds for better convergence and stability. 3) CI Workflow Enhancement: enabled workflow_dispatch across macOS, Ubuntu, and Windows for on-demand testing. 4) Quaternion to Euler Instability Fix: clamped asin input to [-1, 1] to fix numerical instability, with tests. These changes reduce NaN edge cases, improve test coverage, and empower on-demand validation, delivering business value by increasing model robustness and reducing debugging time.
April 2025
5 Commits • 3 Features
Apr 1, 2025April 2025: In facebookresearch/momentum, delivered four focused improvements to robustness, accuracy, and developer productivity. 1) Vertex Error Function Refinement: refactored to separate serial and parallel execution paths, added a dedicated parallel test to ensure accurate error evaluation, improving reliability of vertex error calculations. 2) Vertex Projection Error Function: introduced 2D losses for skinned vertices, plus skinning weight iterator and tests; updated error thresholds for better convergence and stability. 3) CI Workflow Enhancement: enabled workflow_dispatch across macOS, Ubuntu, and Windows for on-demand testing. 4) Quaternion to Euler Instability Fix: clamped asin input to [-1, 1] to fix numerical instability, with tests. These changes reduce NaN edge cases, improve test coverage, and empower on-demand validation, delivering business value by increasing model robustness and reducing debugging time.
March 2025
2 Commits • 1 Features
Mar 1, 20252025-03 Monthly Summary Key deliverables: - VertexErrorFunction: Added a maxThreads option to getGradient and getJacobian to enable multi-threading, improving performance for higher constraint counts (default 0 for serial execution). Commit c30d1694e2920503e22ed5577acf954e9c40f20c (#227). - Solver test reliability: Stabilized tests by adjusting constraint weights and improving random normal vector generation to prevent high error values, yielding robust and deterministic results. Commit 84cd3a4aa243ed0b7de304e36462bfccbf1a5580 (#244). Major bugs fixed: - Reduced intermittent solver test failures; improved test determinism across environments. Overall impact and accomplishments: - Performance uplift for optimization with larger constraint sets; improved reliability and CI readiness; supports scaling Momentum usage in production. Technologies/skills demonstrated: - Parallel computation design and integration (maxThreads), numerical optimization, testing discipline, and traceability with commits.
2 Commits • 1 Features
Mar 1, 20252025-03 Monthly Summary Key deliverables: - VertexErrorFunction: Added a maxThreads option to getGradient and getJacobian to enable multi-threading, improving performance for higher constraint counts (default 0 for serial execution). Commit c30d1694e2920503e22ed5577acf954e9c40f20c (#227). - Solver test reliability: Stabilized tests by adjusting constraint weights and improving random normal vector generation to prevent high error values, yielding robust and deterministic results. Commit 84cd3a4aa243ed0b7de304e36462bfccbf1a5580 (#244). Major bugs fixed: - Reduced intermittent solver test failures; improved test determinism across environments. Overall impact and accomplishments: - Performance uplift for optimization with larger constraint sets; improved reliability and CI readiness; supports scaling Momentum usage in production. Technologies/skills demonstrated: - Parallel computation design and integration (maxThreads), numerical optimization, testing discipline, and traceability with commits.
March 2025
Activity
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Quality Metrics
Correctness95.4%
Maintainability89.0%
Architecture90.4%
Performance85.6%
AI Usage22.8%
Skills & Technologies
Programming Languages
C++JSONPythonYAML
Technical Skills
3D Animation3D Graphics3D Graphics Programming3D Math3D Model Handling3D graphics programming3D modeling3D transformationsAlgorithm AnalysisAlgorithm DesignAlgorithm DevelopmentAlgorithm OptimizationAnimation systemsAutogradC++
Repositories Contributed To
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