Phone-based photogrammetry has evolved from “interesting gimmick” to “actually useful for site documentation” in just three years. We tested the two leading apps—Polycam and Epic Games’ RealityScan—for 7 days across residential renovation, commercial punch list, and civil infrastructure scenarios using an iPhone 15 Pro.
Both apps turn your phone’s camera into a 3D scanner using photogrammetry (multiple photos + computer vision = 3D mesh). But they target different users with different workflows and very different pricing models.
The Quick Verdict
Polycam wins for professional construction use. The $12/month subscription includes CAD export, measurement tools, and web sharing—features that transform photogrammetry from “cool 3D model” to “actionable site documentation.”
RealityScan wins if your budget is literally zero and you have time for manual post-processing. The app is free, mesh quality is excellent, but workflow features are minimal. You’ll spend the time you save on software costs dealing with export limitations.
Testing Scenarios
We captured three real-world scenarios with both apps:
Scenario 1: Residential Kitchen Renovation
- Space: 12′ x 15′ kitchen with cabinets, appliances, windows
- Goal: As-built dimensions for countertop fabrication
- Lighting: Mixed (overhead LED + natural light from window)
- Capture time: 3-4 minutes per app
Scenario 2: Commercial Office Punch List
- Space: 3,000 SF open office with ceiling grid, ductwork, columns
- Goal: Document incomplete finishes and measure ceiling heights
- Lighting: Bright overhead fluorescent
- Capture time: 8-10 minutes per app
Scenario 3: Civil Infrastructure (Retaining Wall)
- Space: 60′ long retaining wall with drainage issues
- Goal: Document cracking, measure wall deflection
- Lighting: Outdoor, overcast day
- Capture time: 5-7 minutes per app
Polycam: The Professional Choice
Mesh Quality: 8/10
Polycam’s reconstruction quality was consistently good across all scenarios. Kitchen cabinets captured with clean edges, office ceiling grid geometry was recognizable, and retaining wall surface detail showed individual blocks clearly.
Not perfect—some texture smearing on reflective surfaces (stainless steel appliances, glass windows) and occasional holes in geometry where lighting was poor (under kitchen cabinets). But 90% of the model was usable without manual cleanup.
Processing time averaged 3-5 minutes per scan on Polycam’s cloud servers. Results appeared in the app automatically when ready.
Measurement Tools: 10/10
This is where Polycam justifies its $12/month price. Built-in measurement tools let you:
- Create dimension lines directly on the 3D mesh
- Measure wall-to-wall, floor-to-ceiling, diagonal distances
- Export measurements as annotated images or PDF reports
- Accuracy: ±0.5-1″ for spaces under 20′, ±2-3″ for larger areas
For the kitchen scenario, we measured cabinet openings, ceiling height, and window dimensions. Compared against tape measure ground truth, Polycam was within 0.75″ on all measurements—acceptable for rough documentation, not sufficient for precision fabrication.
For the retaining wall, we measured crack widths and wall deflection. Results matched physical measurements within 1-2″, good enough to document problems for engineering review.
Export Options: 9/10
Polycam exports to:
- OBJ, FBX, GLTF (standard 3D formats)
- DXF (2D CAD for floor plans)
- LAS (point cloud for integration with laser scan data)
- USD (Universal Scene Description for AR workflows)
The DXF export was surprisingly useful. Polycam automatically generates 2D floor plans from ceiling-down scans, creating dimensioned drawings suitable for basic as-built documentation. Not surveyor-accurate, but sufficient for renovation planning.
Web Sharing: 9/10
Every Polycam scan gets a web link for browser-based viewing. We shared the office scan with a client who viewed it on their iPad, left comments on specific ceiling areas, and we responded in real-time during a Zoom call.
No software installation required. No large file downloads. Just a URL that works on any device. This alone makes Polycam worth the subscription for client-facing documentation.
Limitations
- Reflective surfaces fail: Stainless steel, mirrors, glass create artifacts
- Poor lighting = poor results: Under-cabinet areas, dark corners produced holes
- Scale ambiguity: Small objects (under 2′) can have dimensional errors up to 10%
- Not a laser scanner replacement: Accuracy is ±0.5-1″, not ±1/16″ like terrestrial scanners
Pricing: Polycam
- Free tier: 3 scans/month, web viewing only, no exports
- Pro ($12/month): Unlimited scans, all exports, measurements, web sharing
- Team ($40/month): 5 users, shared project library, collaboration features
For professional use, Pro tier is mandatory. $144/year is trivial compared to terrestrial laser scanners ($15K-50K) or even daily equipment rental ($200-400/day).
RealityScan: Free But Limited
Mesh Quality: 9/10
RealityScan’s reconstruction quality was noticeably better than Polycam—sharper textures, fewer holes, more accurate geometry on complex surfaces. Epic Games’ Unreal Engine photogrammetry tech is genuinely impressive.
The kitchen scan showed individual wood grain on cabinets. The office scan captured ceiling tile perforations. The retaining wall model showed mortar joints between blocks clearly.
Processing happened on-device (iPhone’s neural engine) and took 5-8 minutes per scan—slower than Polycam’s cloud processing but required no internet connection.
Export Options: 3/10
Here’s where RealityScan falls apart for professional use:
- Only exports: OBJ, FBX, USD
- No CAD formats (no DXF, no DWG)
- No point cloud export (no LAS, no E57)
- No measurement tools (can’t dimension anything in-app)
- No web sharing (models stay on your phone unless exported)
To use RealityScan scans professionally, you must:
- Export OBJ file (often 100-300MB)
- Import to desktop software (CloudCompare, MeshLab, or CAD package)
- Manually add measurements and annotations
- Export to final delivery format
This workflow adds 30-60 minutes of post-processing per scan. The “free” software creates paid labor costs that dwarf Polycam’s $12/month.
Web Sharing: 0/10
RealityScan has no web sharing capability. Models exist only on your device or exported as large files. Sharing with clients requires:
- Emailing 200MB OBJ files (good luck)
- Uploading to Dropbox/Google Drive (then client needs software to open)
- Manual conversion to viewable format (more time waste)
For collaboration workflows, this is a dealbreaker.
The Free Advantage
RealityScan is completely free with no scan limits, no watermarks, no trial periods. For students, hobbyists, or firms with zero budget for software, this is valuable.
But “free” creates hidden costs in labor time. Is saving $12/month worth spending 30 minutes per scan on manual workflows? For professional use, probably not.
Side-by-Side Comparison
Kitchen Scan Results:
| Feature | Polycam | RealityScan |
|---|---|---|
| Mesh quality | Good (8/10) | Excellent (9/10) |
| Texture detail | Adequate | Sharp |
| Geometry holes | Few (under cabinets) | Very few |
| Processing time | 3 min (cloud) | 7 min (on-device) |
| Measurement accuracy | ±0.75″ | N/A (no tools) |
| Web share | Yes, instant | No |
| CAD export | Yes (DXF) | No |
Office Scan Results:
| Feature | Polycam | RealityScan |
|---|---|---|
| Ceiling grid clarity | Good | Excellent |
| Large space handling | Adequate | Good |
| Measurement tools | Yes | No |
| Annotation tools | Yes | No |
| Export workflow | 1 step | 3+ steps |
Retaining Wall Results:
| Feature | Polycam | RealityScan |
|---|---|---|
| Surface detail | Good | Excellent |
| Crack visibility | Clear | Very clear |
| Deflection measurement | ±1-2″ | Not possible in-app |
| Outdoor lighting handling | Good | Good |
Use Case Recommendations
Choose Polycam for:
- As-built documentation requiring measurements
- Client-facing presentations (web sharing critical)
- Quick punch list documentation
- Projects requiring CAD export
- Any scenario where time is money
Choose RealityScan for:
- Personal projects with no budget
- Learning photogrammetry workflows
- Situations where mesh quality matters more than workflow
- Offline scanning (no internet required)
- Projects where you’ll do post-processing anyway
Choose Neither (Use Terrestrial Scanner) for:
- Survey-grade documentation (±1/16″ accuracy required)
- Large infrastructure (>10,000 SF spaces)
- Legal/insurance documentation requiring certified accuracy
- Confined spaces or poor lighting conditions
- Projects where liability requires professional scanning
The Real Competition
Both apps compete less with each other and more with traditional documentation methods:
vs. Tape Measure + Photos:
- Photogrammetry is faster for complex spaces
- Measurements are repeatable (model stays accessible)
- Visual context is richer than individual photos
- But: Not suitable for precise fabrication dimensions
vs. Terrestrial Laser Scanners:
- Phone apps are 1/100th the cost
- Setup is faster (no tripod, no scanner calibration)
- But: Accuracy is 10x worse (±1″ vs ±1/16″)
- Range is limited (20-30′ max vs. 300’+ for scanners)
vs. Traditional As-Built CAD:
- Photogrammetry captures what exists, CAD creates idealized drawings
- Faster for complex geometry (curved walls, irregular spaces)
- But: Requires post-processing to create clean CAD deliverables
Bottom Line
For professional construction documentation, Polycam at $12/month is the clear winner. Measurement tools, CAD export, and web sharing transform photogrammetry from “cool tech demo” to “actual workflow improvement.”
RealityScan’s superior mesh quality doesn’t compensate for workflow limitations. Unless your budget is literally zero, the time wasted on manual workflows costs more than Polycam’s subscription.
Final Scores:
- Polycam: 81/100 (excellent value for professional use)
- RealityScan: 78/100 (great mesh quality, poor workflow features)
Both apps prove that phone-based photogrammetry is ready for real construction documentation—just not as a replacement for laser scanners. Use them for quick as-built capture, punch list documentation, and client presentations. Hire a professional surveyor when precision matters.
AECO.DIGITAL SCORE: 81/100 (Polycam), 78/100 (RealityScan)