Get3D Knowledge Center

02 3DGS vs Photogrammetry

3 min read

3DGS vs. Traditional Photogrammetry: A Technical Comparison

Choosing between 3D Gaussian Splatting and classical photogrammetry (SfM + MVS → textured mesh) is not a matter of “which is better” — it is a matter of matching the tool to the task.

Head-to-Head: Seven Dimensions

DimensionReality Mesh (Photogrammetry)3D Gaussian Splatting
Output formatTextured polygonal mesh (OBJ, OSGB, FBX, 3D Tiles)Gaussian point cloud (PLY, proprietary .splat format)
Geometric accuracySub-centimeter with GCPs; measurable surfacesCompetitive but less validated for surveying-grade measurement
Visual fidelityGood, dependent on texture resolution and lightingExcellent; view-dependent rendering captures specularity and transparency
Rendering speed5–15 FPS for dense urban meshes in browser60+ FPS at HD resolution on consumer GPU
File size (10 km² urban)10–50 GB (LOD-optimized OSGB)0.5–5 GB (compressed .ply or .splat)
Post-processing effortHigh — hole filling, texture cleanup, watertight mesh generationLow — training is largely automated; minor outlier removal
GIS tool compatibilityExcellent — supported by Cesium, ArcGIS, QGIS, Bentley, AutodeskEmerging — Cesium integration via 3D Tiles, WebGL viewers available

When to Use Reality Mesh (Photogrammetry)

Classical photogrammetry remains the right choice when:

  • Surveying-grade accuracy is non-negotiable. Infrastructure projects requiring millimeter-level measurement — bridge deformation monitoring, volumetric stockpile calculation, as-built vs. design comparison.
  • Downstream workflows require solid geometry. BIM integration, clash detection, structural simulation, and CAD import all expect watertight mesh.
  • Your GIS platform mandates 3D Tiles or I3S. Reality mesh formats remain the mature, officially supported path.
  • Long-term archival and legal compliance matters. Survey-grade mesh deliverables have established accuracy certification protocols.

When to Use 3D Gaussian Splatting

3DGS is the superior choice when:

  • Visual communication is the primary goal. City council presentations, public consultation, stakeholder briefings — these audiences need to see and understand, not measure.
  • Real-time interaction matters. Web-based digital twin dashboards, emergency response situational awareness, virtual site inspections.
  • The scene contains challenging materials. Glass buildings, water features, metallic infrastructure, translucent canopies.
  • Rapid turnaround is required. A 3DGS reconstruction from existing survey imagery can be trained overnight on a single GPU, where the same dataset through a full photogrammetry pipeline may take 3–5 working days.

Practical Implications for Project Teams

For organizations evaluating both approaches, the decision does not have to be binary. Get3D Mapper supports both traditional mesh output and 3DGS from the same input imagery, allowing teams to choose the right representation per project phase — mesh for surveying deliverables, 3DGS for stakeholder visualization. This dual-output capability eliminates the need to reprocess data when project requirements shift.

The Convergence: Where This Is Heading

The boundary between these two approaches is blurring rapidly:

  • Gaussian surfels extend 3DGS with explicit surface constraints — combining 3DGS rendering quality with measurable geometry.
  • 2D Gaussian Splatting (Huang et al., 2024) enables direct mesh extraction from Gaussian scenes.
  • 3DGS → Mesh conversion pipelines (SuGaR, GS2Mesh) now produce watertight meshes from trained Gaussian scenes.
  • 3D Tiles integration is being actively developed by the Cesium and OGC community.

Result: Within 1–2 years, the industry can expect a unified pipeline combining photogrammetric accuracy with Gaussian-quality rendering.

Source: Get3D Knowledge Center

Graph View