Capturing aerial drone photos correctly is the single most important step in creating high-quality 3D models. The accuracy our photogrammetry output depends on the clarity, consistency, and coverage of the images you collect. By following the below info, you ensure that we can generate a sharp, detailed, and complete 3D model that truly reflect the building surveyed.
Plan Your Mission
Start by defining the type of mission and resolution you need. Proper planning ensures you capture the right coverage and detail for your project.
Modeling Images
Mission Types
Top-Down (Nadir) – Ideal for roofs, open areas, and ground features.
Oblique Orbital Captures – Great to cover facade details.
Target Resolution (GSD): Calculate your Ground Sample Distance (GSD) based on your drone/camera.
Overlap Settings: Use 80% forward overlap and 60% side overlap to ensure images are without gaps.
Flight Patterns for Complete Coverage
A single flight pattern is not enough for a complex structure like a building. A combination of automated and manual flights is required to capture all necessary data.
Whole Building
Nadir + Oblique above + Oblique on facades
For the most complete and accurate 3D reconstruction, use a combination of nadir and oblique captures. Each flight path captures different perspectives of the structure, and together they eliminate gaps and distortions in the model.
Nadir (Top-Down): Captures the roof, open areas, and ground surfaces directly from above. This ensures accurate geometry of flat or horizontal surfaces.
Oblique Above: Adds angled imagery around the roof from higher orbits. These shots capture slopes, edges, and roof details that a nadir-only flight can miss.
Oblique on Facades: Completes the dataset by capturing vertical walls and facades at a 30–45° gimbal angle. This ensures walls are not “stretched” or distorted during photogrammetry.
Pro Tip: Overlap your captures across all three paths (80/60) and ensure smooth transitions between nadir and oblique flights. This layered approach provides SKAND with enough coverage to generate sharp, accurate models of both horizontal and vertical surfaces.
Note: The number of oblique on facade orbits depends on the building’s height:
1-4 stories: 1–2 oblique circles
5-9 stories: 3 oblique circles
10 or more stories: 4 or more, depending on overall height
Ensure the vertical spacing between each orbit is consistent to maintain precision and accuracy in the 3D reconstruction.
Roof
Nadir (Top-Down) Grid
This flight captures the roof and surrounding ground area. It forms the foundation of your model.
Purpose: To capture a top-down view of the entire site.
Execution: Fly a standard grid pattern directly over the building. Ensure your flight path extends well beyond the building's footprint to capture the immediate surroundings.
Overlap: Aim for 80% front and 80% side overlap. This is crucial for the software to stitch the images together accurately.
Oblique (Angled) Orbits
Oblique captures are essential when surveying roofs with complex shapes, varying slopes, or features that can’t be fully captured with only top-down imagery. Capturing at an angle helps SKAND reconstruct details such as edges, chimneys, skylights, and roof penetrations more accurately.
Flight Path: Fly circular orbits around the roof, with the gimbal angled 30–45° towards the structure.
Overlap: Maintain at least 75% overlap between images, both across orbits and along each orbit line.
Altitude: Adjust altitude to match the roof’s highest point plus your target offset distance, ensuring consistent resolution (GSD).
Detail Capture: Include multiple oblique passes at different heights if the roof has dormers, steep slopes, or protruding structures.
Pro Tip: Combine oblique roof captures with your top-down mission for complete coverage. This reduces reconstruction errors around roof edges and produces sharper 3D geometry in SKAND.
Facade
Oblique (Angled) Orbits
Oblique photos capture the building's facades (the walls). Without these, you'll end up with stretched, low-quality vertical surfaces.
Purpose: To capture detailed imagery of the building's sides.
Execution: Fly multiple circular or grid-based orbits around the building at different altitudes.
A good strategy is to break the building into three parts: the base, the middle, and the top.
The bottom pass: Plan your first orbital mission low to the ground. This pass is crucial for capturing architectural features at eye level and ensuring good overlap with your ground-based photos.
The middle pass: Set a second orbital mission halfway up the building. This captures the midsection, including features like balconies, window frames, and decorative details that aren't visible from the ground or top-down views.
The top pass: Plan your final orbital mission near the top of the building, just below the roofline. This pass helps capture high-level details and effectively "bridges" the gap between your facade and roof data.
Pro Tip: The goal is to see the entire face of the building in each shot and minimise the horizon.
Camera Settings
Set your camera correctly before flying to ensure sharp, well-lit, and consistent images.
Use a 20MP camera or higher for best quality.
White Balance: Set manually (e.g., “sunny” or “cloudy”) and keep it consistent across flights.
Shutter Speed: At least 1/500 (avoid going below 1/250).
ISO: Keep below 3200 to reduce noise.
Image Format: JPEG, 4:3 or 3:2 aspect ratio.
Capture Best Practices
Apply proven capture methods to cover all surfaces, transitions, and finer details.
Flight Lines: Maintain consistent spacing and overlap. For complex structures, consider cross-pattern flight lines.
Transition Shots: Take extra photos around corners and when moving between top-down and facade captures.
Detail Capture: Orbit and capture skylights, antennas, chimneys, or visible damage if required.
Ensuring proper data acquisition will help us in creating consistent and quality 3D models. You can watch this video to add to the above insights .
If you need further assistance, you can reach us at support@skand.io.