Contents
I. For AI / Machine Learning Training Data
II. For 3D Model Annotation & Documentation
III. For Medical & Volumetric Data (CT, MRI)
Key Factors to Consider When Choosing
Conclusion
Encord Blog
Best Tools for Labeling 3D Files in 2025
The "best" tool for labeling 3D files heavily depends on several factors:
Type of 3D Data: Are you labeling point clouds, meshes, volumetric data (like CT/MRI scans), or CAD models?
Type of Labeling: Do you need bounding boxes (cuboids), semantic segmentation (pixel-level classification), instance segmentation (distinguishing individual objects), keypoint annotation, material annotation, or just simple text annotations for documentation?
Purpose: Is this for machine learning/AI training, quality control, documentation, or design review?
Scale of Project: Is it a one-off task, or do you need to label massive datasets with a team?
Budget & Resources: Are you looking for free/open-source solutions, or do you have a budget for commercial tools or managed services?
Required Output Format: What format does your downstream application or ML model expect (e.g., KITTI, COCO, custom JSON)?
Given these variables, here's a breakdown of excellent tools categorized by their common use cases:
I. For AI / Machine Learning Training Data
This category focuses on creating structured annotations (bounding boxes, segmentation masks, keypoints) that an AI model can learn from.
A. Point Cloud & 3D Annotation Platforms (LiDAR, 3D Scans, Multi-Modal Data)
Supervisely
Pros: Comprehensive platform for image, video, and 3D data. Supports point clouds with cuboid bounding boxes, polygonal segmentation on slices, and semantic labeling. Strong collaboration features, powerful automation (NN-based pre-labeling). Can be self-hosted or cloud-based.
Cons: Can have a learning curve; commercial for larger teams/datasets (though free tiers exist).
Best for: Large-scale AI projects with diverse data types.
Encord
Pros: Enterprise-grade data annotation platform with strong support for 3D point clouds, cuboids, semantic segmentation, and multi-sensor fusion (LiDAR + camera). Excellent workflow orchestration, quality assurance, active learning, and model-in-the-loop labeling. Designed to scale with ML teams and integrates well into modern ML pipelines.
Cons: Commercial/enterprise pricing; not intended for casual or one-off annotation tasks.
Best for: ML teams building production-grade perception systems (autonomous driving, robotics, mapping, AR/VR) that require scalable, high-quality 3D annotations and dataset management.
Scale AI / Labelbox / V7 Data
Pros: Managed data labeling services combined with robust platforms. They handle workforce, QA, and tooling. Support various 3D annotation types (cuboids, point cloud segmentation, 3D tracking).
Cons: Enterprise-grade pricing; less direct control if using managed labeling services.
Best for: Companies with large budgets and high-volume, high-quality data labeling needs (automotive, robotics, AR/VR).
CVAT (with 3D support)
Pros: Open-source, self-hostable, and customizable. Supports 3D bounding boxes for point clouds via plugins. Full control over infrastructure.
Cons: Requires setup and maintenance; 3D features are newer and less polished than commercial platforms.
Best for: Researchers, startups, or technically strong teams with limited budgets.
CloudCompare
Pros: Free, open-source, powerful for point cloud and mesh visualization, manual segmentation, and classification.
Cons: Not a dedicated ML labeling platform; limited collaboration and automation.
Best for: Academic research, small-scale manual segmentation, or pre-processing workflows.
Blender (with custom scripts/add-ons)
Pros: Free, open-source, extremely flexible. Can be scripted to create custom annotation pipelines; useful for detailed mesh-level labeling and synthetic data generation.
Cons: High learning curve; not optimized for high-throughput labeling without heavy customization.
Best for: Highly customized annotation needs or complex mesh segmentation.
B. Mesh / Object-Based 3D Model Labeling
Blender
Excellent for part-level mesh segmentation, material assignment, and object-level labeling.
3D CAD / DCC Software
Examples: Maya, 3ds Max, SolidWorks, AutoCAD
Pros: Precise part naming, assemblies, dimensions, and material metadata.
Cons: Expensive; not designed for ML-style dataset annotation.
Best for: Engineered products, architecture, or synthetic dataset creation.
II. For 3D Model Annotation & Documentation
3D PDF / Viewer-Based Annotation Tools
Modern CAD viewers and web-based platforms allow text notes, measurements, and callouts.
Dedicated 3D Viewers & Review Software
Examples: eDrawings, Autodesk Forge Viewer / A360, AR/VR inspection tools
Best for: Design review, quality control, collaboration, and documentation—not ML training.
III. For Medical & Volumetric Data (CT, MRI)
3D Slicer
Industry-standard for medical image segmentation and 3D visualization.
ITK-SNAP
Strong for manual and semi-automatic anatomical segmentation.
Key Factors to Consider When Choosing
- Data format (.las, .pcd, .obj, .stl, .nii, .dicom, .step)
- Annotation granularity (object vs per-point/per-voxel)
- Automation & AI-assisted labeling
- Scalability and collaboration
- Integration with ML pipelines and export formats
Conclusion
For AI / Machine Learning applications, especially at scale, Supervisely, Encord, Scale AI, Labelbox, and V7 Data are leading solutions.
Encord stands out for enterprise-scale 3D perception workflows, multi-sensor data, and model-in-the-loop dataset iteration.
CVAT is the strongest open-source option.
CloudCompare and Blender excel for specialized or manual workflows.
For human-readable documentation and design review, traditional CAD tools and 3D viewers remain the best fit.
As always, clearly define your data type, annotation needs, scale, and end goal before choosing a tool.
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