Creating 3D Models from Photos: A Photogrammetry Guide

What Is Photogrammetry?

Photogrammetry is a technique where photos taken from different angles of an object are analyzed by computer software to create a 3D model. The software detects common points across photos, calculates camera positions, and generates a three-dimensional point cloud from this data.

The Photogrammetry Process

Step 1: Preparing the Shooting Environment

• Use diffused, even lighting. Hard shadows cause errors in the model.
• Choose a single-color, matte background. Shiny or patterned surfaces mislead the software.
• Place the product on a stable platform. If using a turntable, keep the camera fixed.

Step 2: Taking Photos

Systematically photograph around the product:

1. Rotate 360 degrees around the product, taking a photo every 10-15 degrees (24-36 photos)
2. Repeat the same pass at different heights (low, mid, high angle)
3. 60-100 total photos is ideal
4. Each photo should have at least 60-70 percent overlap with adjacent shots

Camera settings:

• Use manual mode - exposure should not change between shots
• Prefer low ISO (100-400)
• Use aperture between f/8 and f/11 for full product sharpness
• High quality JPEG is sufficient over RAW

Step 3: Software Processing

Upload photos to photogrammetry software. It automatically performs:

1. Feature Detection: Distinctive points identified in each photo
2. Feature Matching: Common points across different photos are matched
3. Point Cloud: 3D point cloud generated from matched points
4. Mesh Generation: Points connected to form solid surfaces
5. Texture Mapping: Color information transferred from photos to model

Software Options

Key Considerations

• Reflective surfaces: Mirror-like shiny, transparent, or uniform matte surfaces are difficult for photogrammetry. Temporary matte spray can help.
• Post-processing: Photogrammetry output typically has high polygon counts and needs optimization for web.
• Scale calibration: Calibrate real-world dimensions using a reference measurement point.

Conclusion

Photogrammetry is an effective method for creating 3D models, especially for organic and complex geometries. It does not require professional equipment; a good camera and proper technique can produce successful results.