Exterior Scanning
Capture building exteriors using Harv.ant's photo scan mode. This guide covers planning your passes, photo count, lighting conditions, and handling complex facades.
Before you start
Exterior scanning uses photogrammetry — cloud processing converts your photos into a 3D model. Unlike interior LiDAR scanning, it requires good lighting and enough clearance to walk around the building.
Best conditions
- Overcast days are ideal — soft, even light with no harsh shadows or bright reflections
- Avoid scanning in direct midday sun — strong shadows make photogrammetry less accurate
- Early morning or late afternoon works if the sun is low and not directly facing your primary elevation
- Avoid wind — moving foliage near the building creates noise in the point cloud
- Dry conditions only — wet surfaces reflect inconsistently
Planning your walk
Before you start, walk the full perimeter once without your phone. Identify any access constraints — fences, parked cars, tight boundary conditions — and plan how you'll handle them. For tightly constrained sites, plan supplementary elevation shots from across the street.
The pass method
Exterior scanning works in passes — each pass captures the building from a different height or angle, building up complete coverage of all faces.
Eye-level perimeter
Walk the full perimeter at a steady pace, phone at chest height, angled slightly upward at ~30°. Stay 3–5m from the building face.
Low-angle perimeter
Repeat the perimeter walk with the phone angled downward at ~45°. Captures the base, ground connection and lower facade detail.
Elevation faces
Stand back and capture each elevation face straight-on from multiple positions. Walk across each face in a grid pattern, overlapping shots by 60–70%.
High-angle pass
For buildings with complex rooflines, parapets or upper-floor features, add a pass from a higher vantage point — an adjacent window, balcony or raised ground.
Step-by-step capture
Start at a corner
Always begin and end at the same corner of the building. This helps Harv.ant close the loop and stitch the model correctly. Mark the corner with a physical reference if needed.
Walk slowly and steadily
Move at a slow walking pace — roughly half your normal speed. Take a photo every 1–2 steps. Keep the phone steady and avoid rotating it mid-shot.
Capture building corners carefully
At each building corner, slow down further and capture from directly in front of the corner, then from both adjacent faces. Corners are where models most commonly have gaps.
Cover all elevation faces
After the perimeter walks, stand back from each elevation and capture it in a grid — left to right across the face, then step back and repeat. Each shot should overlap the previous by at least 60%.
Capture roof edges and eaves
Angle the phone upward at 60° and walk the perimeter one more time to capture the roofline, eaves and any parapet detail. This is especially important for heritage buildings.
Check your count before leaving
For a typical house, you should have 150–300 photos before uploading. For a larger commercial building, 300–500. Check your camera roll before leaving site — it's much easier to fill gaps on the day.
Photo count guide
| Building type | Recommended photos | Passes |
|---|---|---|
| Single-storey house | 150–200 | 3 passes |
| Double-storey house | 200–280 | 3–4 passes |
| Small commercial building | 280–400 | 4 passes |
| Complex / heritage facade | 400–600 | 4–5 passes + close-ups |