--- title: "Scan Facades - NavVis MLX" slug: "cop-967-best-practices-for-scanning-facades-with-navvis-mlx" description: "Facade scanning with NavVis MLX handles glass, long plain walls and recessed entrances. Walk the perimeter at a slight angle, add offset return passes, slow down at recesses, bays and canopies, then overlap your start point." updated: 2026-06-03T09:12:05Z published: 2026-06-03T09:12:05Z canonical: "knowledge.navvis.com/cop-967-best-practices-for-scanning-facades-with-navvis-mlx" --- > ## Documentation Index > Fetch the complete documentation index at: https://knowledge.navvis.com/llms.txt > Use this file to discover all available pages before exploring further. # Scan Facades - NavVis MLX ## Introduction Use this guide when scanning a building facade for the first time with NavVis MLX, especially with tricky elements like glass, long plain walls, or recessed entrances. You'll need the building plan, and a clear, feature-rich start point. By the end, you'll have complete facade coverage ready for alignment with interior scans. # Before You Go on Site ## 1. Analyze the building plan - Identify all facades you must capture. - Note corners, doors, canopies, overhangs, deep doorways or recesses, and large glass areas. - Mark areas that may need extra passes, such as long, uniform walls or recessed entrances. ## 2. Choose a clear start point - Select a spot that is easy to find again, such as a main entrance. - Prefer locations with features like frames, columns, ceilings, signs. These details help: - Align neighboring scans. - Verify alignment quality in the overlap areas. # Best Practices for Scanning Facades ## 1. Walk the perimeter of the building - Keep the facade in view the whole time. - Avoid walking too close and perfectly parallel to facade. Stay at a slight angle so window frames stay visible. ![A woman uses a device while walking along a pathway near a building.](https://cdn.document360.io/bf174766-fa1a-4fe1-a4d7-b1db1e7cb996/Images/Documentation/facade MLX 1.jpg?sv=2026-02-06&spr=https&st=2026-10-14T07%3A48%3A47Z&se=2026-10-14T08%3A48%3A47Z&sr=c&sp=r&sig=5fM3EFI9aQwfwspmIuT9Y6kFnqSXvrQcmm3f3JXQlTI%3D) - Make sure you pass corners, columns, signs, and downspouts. These features help the SLAM algorithm keep track of your movement. ## 2. Add a few return passes On long, straight sides of the building: - Walk along the facade at a distance that achieves the point cloud density required for your project. - Then walk back along the same side, slightly shifted from your initial path, so that you cross your previous path regularly. You do not need additional panoramic images here; they are already captured during your walk. ![A diagram illustrating a complex pathway with directional arrows indicating movement.](https://cdn.document360.io/bf174766-fa1a-4fe1-a4d7-b1db1e7cb996/Images/Documentation/loop-closures-image-sxfpf90o(1).png?sv=2026-02-06&spr=https&st=2026-10-14T07%3A48%3A47Z&se=2026-10-14T08%3A48%3A47Z&sr=c&sp=r&sig=5fM3EFI9aQwfwspmIuT9Y6kFnqSXvrQcmm3f3JXQlTI%3D) - By walking forward and then backward with a slight offset, you - Improve the coverage of the final point cloud. - Provide more information for the SLAM algorithm to reconstruct a more accurate point cloud. ## 3. Pay attention to depth changes For areas such as recesses, bays, arcades, or big canopies: - Slow down and keep the device steady. - Make more than one pass around these features to improve coverage of all surfaces. - Add a slow turn so NavVis MLX sees all parts of the facade, including ceilings, beams, and underside details. ![A person holding a device near a building entrance, preparing for data collection.](https://cdn.document360.io/bf174766-fa1a-4fe1-a4d7-b1db1e7cb996/Images/Documentation/facade MLX 2.jpg?sv=2026-02-06&spr=https&st=2026-10-14T07%3A48%3A47Z&se=2026-10-14T08%3A48%3A47Z&sr=c&sp=r&sig=5fM3EFI9aQwfwspmIuT9Y6kFnqSXvrQcmm3f3JXQlTI%3D) ## 4. Finish with overlap at your starting point - Return to your starting location, but ensure there is some overlap rather than just touching the start point. - If scanning inside as well, re-enter and end the scan near where you began. This loop closure is important for alignment. **View this short video on scanning a facades:** [Scanning a Facade with the NavVis MLX](https://player.vimeo.com/video/1159663423?h=88433b0fce&badge=0&autopause=0&player_id=0&app_id=58479) --- ### FAQ #### What is the purpose of this guide? This guide is designed to assist users in scanning a building facade for the first time with NavVis MLX, particularly when dealing with challenging elements. #### What should I analyze before going on site? You should analyze the building plan to identify all facades to capture, noting features like corners, doors, and large glass areas. #### How do I choose a clear start point for scanning? Select a spot that is easy to find again, such as a main entrance, preferably with features that help align neighboring scans. #### Is it necessary to walk the perimeter of the building? Yes, walking the perimeter while keeping the facade in view is crucial for effective scanning. #### Should I make return passes on long, straight sides of the building? Yes, adding return passes helps improve the coverage of the final point cloud. #### What should I do in areas with depth changes? In such areas, slow down, keep the device steady, and make multiple passes to improve coverage. #### Is it important to finish with overlap at the starting point? Yes, ensuring overlap at the starting point is important for alignment, especially if scanning inside as well. #### Can I view a video on scanning facades? Yes, there is a short video available that demonstrates how to scan facades.