Aligning Datasets

Use this guide to place your datasets at the correct coordinates relative to each other and form a single, coherent Site Model. You need processed datasets uploaded to NavVis IVION.

Alignment happens automatically during processing for most projects. If your datasets do not qualify for automatic alignment, you can align them manually in Dataset Alignment.

Automatic or manual alignment

NavVis IVION aligns your datasets automatically when any of the following applies:

• You processed your data with control points measured by a total station.

• CDA was switched on when the dataset was processed in NavVis IVION Processing.

If none of the above applies, align your datasets manually using the Manual Alignment procedure.

For greater accuracy during the processing phase use control points or CDA, especially for large scans.

Automatic alignment

How Cross-Dataset Alignment (CDA) works

CDA aligns datasets to each other during processing. It uses either surveyed or unmeasured control points. CDA-aligned datasets show a link icon in Dataset Management and Dataset Alignment. The icon indicates that the datasets belong to a CDA group and that NavVis IVION Processing has already aligned and optimized them.

For how CDA-linked datasets behave during manual alignment, go to Working with CDA-linked datasets.

Verify alignment with surveyed control points

Use the Control Point Verification Log to check alignment when you used control points measured by a total station.

1. Go to Data Processing > Processed Data.
   

2. Select the datasets you want to check.

   

3. Click Download.

   

4. Select Control point verification log as the output file.

   

5. Open the log file and check the third column for the difference between each dataset and its control points, to find out how successful the alignment was during processing:

   

   • Less than 4 cm: alignment is successful.

   • 5 to 6 cm: alignment may be acceptable, depending on your use case.

   • More than 6 cm: alignment is not successful.

6. If the alignment was not as you expected or the differences were greater than 6 cm, process the datasets again and exclude the control points with large differences.

Verify CDA alignment

The Control Point Verification Log only covers alignment to surveyed control points. CDA-aligned datasets without surveyed control points do not appear in the log, so a visual check is required.

1. Open Dataset Alignment.

2. Load the linked datasets.

3. In the Top View and Side Views, confirm that overlapping walls and features line up between linked datasets.

4. If the alignment is off, refine it manually using the Transform menu, or click Run automatic alignment on the dataset that needs adjusting.

Manual alignment

Use manual alignment only for datasets captured without control points and not aligned by CDA.

The workflow has five phases:

1. Select a reference dataset.

2. Align datasets on the same floor.

3. Anchor the building to the ground floor.

4. Align the remaining floors vertically.

5. Place the building on the world map.

Note: Save your work after every adjustment. Click Save before moving on to the next step.

Before you start

• Have the floor plan you used during scanning ready, so you can identify which datasets overlap.

• Confirm that every dataset in the building is uploaded.

• In Dataset Alignment, click Show Map. Verify that the datasets are roughly aligned with the building outline on the street map. If they are not, adjust the dataset position manually before continuing.

Working with CDA-linked datasets

During manual alignment, datasets that are CDA-aligned display a link icon in both Dataset Management and Dataset Alignment, and they function collectively as a group.

• Shared color: Linked datasets share a color for easy identification. You can change the group color for QA/QC purposes.

• Group lock/unlock: Lock or unlock all datasets in the group with a single action.

• Run automatic alignment per dataset: If a single dataset within the group needs fine-tuning, you can run automatic alignment on just that dataset.

• Unlinking: Click a dataset’s link icon to remove it from the group. Unlinking cannot be undone. To restore the link, unload the remaining datasets in the group and re-add them from Processed Data.

• Adding a new dataset to a group: Align it manually or with Run automatic alignment. Aligning one entire CDA group directly to another CDA group is not supported in this version.

The View Configuration menu

The View Configuration menu controls the panels you use during manual alignment. Familiarize yourself with each panel before you start:

• Top View:  A bird’s-eye view of the datasets. Most rough alignment happens here.

• Side View (N–S): A cross-section from north to south. The highlighted rectangle in the Top View shows what is visible here.

• Click and drag the rectangle to move the slice; hold Shift while dragging to rotate it.

• Side View (E–W): A cross-section from east to west. Same controls as the N–S side view.

• Hold shift to rotate the highlighted area.

• Perspective Camera: Shows the angle of the point cloud in 3D.

• Show Map: Overlays a street map onto the Top View. You can hide the map if it does not help you align your datasets.

1. Select a reference dataset

The reference dataset is the starting point for alignment. Every dataset aligns to it.

1. Go to Site Setup > Dataset Alignment.

2. Using your floor plan, identify the floor of the building that contains the most datasets. Start there.

3. On that floor, pick a dataset that overlaps with several other datasets and contains features visible across multiple stories (for example, staircases or elevator shafts).

4. In the Datasets list, click the eye icon next to each remaining dataset to hide it

   

   5. Click the star button to set the dataset as the reference.

   

   6. Assign it a color in the color picker.

   

   7. If the reference dataset is not already locked, click the lock button to lock it in place.

   

2. Align datasets on the same floor

Repeat the following steps for each additional dataset on the same floor as your reference. Always work with two datasets at a time: the locked reference (or a previously aligned dataset) and the new dataset you are aligning.

Note: If both datasets belong to the same CDA group, they are already roughly aligned. Skip steps 6 to 11 (rough alignment in Top and Side Views) and go straight to step 13. Run automatic alignment for a final adjustment.

1. Select a second dataset on the same floor that overlaps with the reference. Use your floor plan to confirm overlap.

2. Click the eye icon to unhide the dataset.

3. In the color picker, assign the second dataset a color that contrasts with the reference, so you can tell them apart.

4. Click the lock button to unlock the second dataset. Keep the reference dataset locked.

Note: Keep all datasets locked by default. Only unlock the dataset you are actively aligning.

5. Click Save.

6. Click the Top View label to bring the Top View into full screen.

7. Scroll the mouse wheel to zoom in or out until both datasets are visible. To center on a specific dataset, click the bullseye button next to its name.

8. Using the Transform menu, drag and rotate the unlocked dataset until the walls of both datasets match.

9. Zoom in further and align identifying features that appear in both datasets including stairs, windows, doors, elevator shafts, or pillars.

   

   • Click the Top View label again to return to the split screen, then click a Side View label to enter full screen and check that the floor is also lined up from the side.

   

10. Click one of the Side View labels to enter the full screen and further inspect whether the datasets are roughly aligned. In the images below, you can see what unaligned versus aligned datasets look like from a Side View.

    

    

11. Continue to use the Transform menu to match the datasets in the Top View and two Side Views until the overlapping datasets are roughly aligned in all three views.

12. Click Save.

13. Run automatic alignment to refine the result:

    • Confirm that all other datasets are hidden, the reference dataset is locked, and the second dataset is unlocked.

    • Click Run automatic alignment.

• Select Align horizontally and vertically or Align horizontally only.

14. Read the reported difference between the two datasets. A result of 40 mm or less indicates a successful automatic alignment.

15. Review the result:

    1. • If the walls line up and the difference is 40 mm or less, click Save and go to step 17.

       • If the walls do not line up, click Undo and continue with step 16.

16. If you receive an error message, return to each view, adjust the alignment manually, and run automatic alignment again.

17. After automatic alignment (successful or not), refine the position manually with the Transform menu as precisely as possible.

18. Once you are satisfied, click the lock button to lock the second dataset.

19. Click Save.

20. In the color picker, change the second dataset’s color to match the reference. This makes it easy to see which datasets on this floor are already aligned, and is required for the later vertical alignment step.

    

21. Click Save.

22. Pick another dataset on the same floor that overlaps with the reference (or with a dataset you already aligned) and repeat steps 1 to 20.

23. When no more datasets overlap with the current reference, choose a new reference dataset on the same floor and continue until every dataset on that floor is aligned.

24. Click Publish once the floor is fully aligned.

3. Anchor the building to the ground floor

This step positions the building so the ground floor sits at the correct height Move the building as a whole. Do not adjust the alignment between datasets.

1. Go to Site Setup > Dataset Alignment.

2. Click the eye icon next to each aligned dataset to unhide the datasets you want to include in your Site Model.

3. In the Side Views, check whether the ground-floor datasets sit on the gray line. If they do, you can go straight to Auto-generating your Site Model.

4. If the ground-floor datasets are not on the gray line, click the lock icon next to the building label to unlock the entire building.

5. Use the Transform menu to move the building onto the gray line:

   • Use the rotation buttons to rotate in small increments.

   • Use the left and right arrows to move in small increments along the x, y, and z axes.

6. Once the building is on the gray line, lock the datasets again.

7. Click Save.

8. Click Publish.

4. Align floors vertically

Align one floor at a time, working outward from the floor you anchored. Always align a new floor to a previously aligned and locked floor.

1. Choose a floor vertically adjacent to the one you just aligned. For example, if you aligned the fourth floor, work on the third or fifth next.

2. In the color picker, assign every dataset on the new floor the same color, so you can clearly identify which floor each dataset belongs to.

   

3. Click the eye icon next to both floor names to unhide all datasets on both floors.

4. Unlock only the datasets on the new floor. Keep the datasets on the previously aligned floor locked.

5. Click the Top View label to enter full screen.

   

6. In the Top View, use the Transform menu to drag and rotate the unlocked datasets until the walls of both floors match.

   

7. Zoom in and align identifying features that overlap between the floors, such as stairs, windows, doors, elevator shafts, or pillars. This makes the Side View alignment easier.

   

8. Click Save.

9. Return to split screen. The floors are now aligned in the Top View; you still need to connect them in the Side Views.

10. In the View Configuration menu, switch on Side View (N to S), Side View (E to W), or both. A clipping rectangle appears in the Top View.

11. Use the rectangle in the Top View to control what appears in the Side View below:

    • Scroll over the rectangle to resize it.

    • Drag the rectangle to move it.

    • Hold Shift while moving the rectangle to rotate the slice

      

12. Once the feature you want to align is in focus, click the Side View label to enter full screen for a better look.

    

13. Using the Transform menu, move the unlocked datasets so they connect to the locked floor.

    

14. Click Save.

15. Switch to the other Side View and double-check that the floors are aligned there too. Return to the main split-screen overview.

Note: Each story should have a small gap between the floor of one dataset and the ceiling of the dataset below. If a gap is not possible, cut off the ceiling rather than the floor.

16. Lock the datasets you moved.

17. Click Save.

18. Back in the Top View, check the floor you just connected for alignment errors:

    • Start in the middle of the building and confirm that overlapping features like staircases and windows match.

    

19. The outlines should match between floors.  If they cannot, distribute the error across the building rather than concentrating it in one area.

    

20. Click Save.

21. If you find misaligned areas, choose a new reference dataset on that floor and repeat the same-floor alignment steps. Then use the Transform menu to refine the result.

22. Once you are satisfied with the two floors, move to the next floor and repeat. For example, if you have aligned the fourth and fifth floors, align the sixth floor to the fifth next.

23. Click Publish once you have finished aligning the datasets.

5. Place the building on the world map

Skip this section if you already placed your site on the world map using site coordinates. Otherwise, anchor the aligned building to its real-world location:

1. Select all datasets.

2. Open the Top View.

3. If the Top View does not show a map, enable Show Map in the View Configuration menu.

4. To make positioning easier, click the eye icon next to Site Base Point to make the base point visible.

   

5. Unlock all datasets so they can be moved as a group. A bounding box appears around your datasets.

   

6. Drag the bounding box to the correct location on the map. If necessary, use the rotation arrow to set the correct angle.

7. Click Save.

8. Click Publish once you have finished aligning the datasets.