How to scan with Kiri?

Scanning with Kiri Engine involves using your smartphone camera to capture a series of images around an object, which the app then processes to create a 3D model. This process, known as photogrammetry, transforms multiple 2D photos into a detailed 3D representation.

Getting Started with Kiri Engine

Before you begin, ensure you have the Kiri Engine app installed on your smartphone. When first using the app, you may need to allow Kiri Engine access to your camera to enable photo capture. Good lighting and a stable environment are crucial for successful scans.

Essential Preparation for a Successful Scan

A well-prepared setup significantly improves the quality of your 3D model:

• Lighting: Use diffused, even lighting. Avoid direct sunlight, harsh shadows, or highly reflective surfaces, as these can confuse the software. Natural indirect light or a lightbox works best.
• Background: Opt for a plain, non-reflective, and uncluttered background that contrasts with your object. A solid color sheet or a dedicated photogrammetry turntable background can be ideal.
• Object Stability: Ensure your object is completely still throughout the scanning process. Any movement will result in blurry photos and a distorted model.
• Surface Texture: Objects with rich textures and intricate details are easier for photogrammetry software to process. Highly reflective, transparent, or uniformly colored objects (e.g., a shiny black sphere or clear glass) can be challenging. You might need to dust them with a temporary matte spray or powder to add texture.

Two Main Ways to Scan Your Object with Kiri Engine

There are two primary methods for capturing photos for your 3D scan, depending on your object and setup:

1. Keeping the Object Stationary and Walking Around It:

   • This is often the most common and recommended method for larger or immovable objects.
   • Place your object on a stable surface.
   • Walk slowly and smoothly around the object, taking photos from various angles and heights.
   • Ensure a consistent distance between your camera and the object as you circle it.

2. Keeping the Camera Stationary and Rotating the Object:

   • This method is ideal for smaller objects and can yield very consistent results.
   • Place your object on a manual or motorized turntable.
   • Position your camera (smartphone) on a tripod or a stable surface, ensuring it remains perfectly still.
   • Rotate the object incrementally, taking photos at each stop.

Step-by-Step Photo Capture Guide

Regardless of the method you choose, the principles for taking photos remain similar:

1. Initial Photo Pass (Horizontal):

   • Start by taking photos horizontally around the object, ensuring significant overlap between each shot (aim for 70-80% overlap).
   • Take a full circle of photos, gradually moving your camera around the object.
   • Example: For a cup, take photos directly at its mid-height.

2. Second Photo Pass (Angled Down):

   • Elevate your camera slightly and angle it downwards towards the object.
   • Complete another full circle of photos.
   • This captures the top surfaces and upper sides of the object.
   • Example: For the cup, take photos from slightly above, looking down at an angle.

3. Third Photo Pass (Angled Up - if necessary):

   • If your object has intricate details on its underside or base that need to be captured, lower your camera and angle it upwards.
   • Complete a third circle of photos.
   • Example: For the cup, take photos from slightly below, looking up at an angle, especially if the base has distinct features.

4. Detail Shots (if needed):

   • For highly detailed areas, take additional, closer-up photos.
   • Maintain overlap with previous shots.

Tips for Optimal Photo Capture

• Overlap is Key: Ensure each photo overlaps significantly with the previous one. This provides the Kiri Engine with enough visual information to stitch the images together accurately.
• Consistent Distance: Try to maintain a relatively consistent distance from your object throughout the scan.
• Sharp Focus: Make sure every photo is in sharp focus. Blurry images will degrade the 3D model's quality.
• Avoid Movement: Both your object and your camera should be still during each shot. Use a tripod for the camera whenever possible, especially when rotating the object.
• Number of Photos: While there's no strict number, more photos generally lead to a more detailed and accurate model. For small to medium objects, 50-200 photos are common, but complex objects might require many more. Kiri Engine typically handles a good range of photo counts.
• Lighting Consistency: Ensure the lighting conditions do not change significantly between photos.
• No Filters or Zoom: Avoid using camera filters, digital zoom, or ultrawide lenses during capture, as these can introduce distortions.

Processing and Exporting Your Model

Once you've captured all your photos, Kiri Engine uploads them to its servers for processing. The app uses advanced algorithms to reconstruct the 3D geometry and texture from your image set. After processing is complete, you can:

• View your 3D model directly within the app.
• Clean up any unwanted background elements using built-in tools.
• Export your 3D model in various common formats (e.g., OBJ, FBX, GLB), making it ready for use in other 3D software, game engines, or for 3D printing.

By following these steps and tips, you can effectively use Kiri Engine to transform real-world objects into high-quality 3D digital models.