Point Clouds
The point cloud commands: reading survey files (LAS, LAZ, E57, PLY, text) into the project, cleaning and classifying the points, aligning scans, and getting surfaces, volumes, sections, bench edges and comparisons out of them. Each command has its own section; press F1 over a ribbon button, or the ? in the title bar of a command's window, to open it.
Most commands work on the selected point clouds and change them in one undo step (Ctrl+Z). Long ones run as a background job with a progress bar and can be cancelled. A cloud on a locked layer is not changed.
Import point cloud
Reads LAS, LAZ, E57, PLY or text point files into the project as point clouds and frames the view on them.
Where to find it
Point Clouds tab → Exchange group → Import point cloud (Import).
How to
- Click Import point cloud. In the file dialog choose one or more files. The filter lists LAS / LAZ, E57, Text (
.xyz,.txt,.csv,.pts,.asc) and PLY. - If any chosen file is LAS or LAZ, the Import point cloud window opens (see below). Otherwise, with several files, a question asks "Import the N files as one cloud? Yes: one cloud of all of them. No: a cloud for each file."
- For each text file the Text file columns window opens (see below). Files with the same number of columns and separator as one already checked take its choice.
- The points are read in the background. The clouds are added to the layer Point clouds (created if missing), each named after its file.
The LAS import window
| Area | Meaning |
|---|---|
| 1. Files | Each file's header: LAS version, point format, number of points, size in metres, coordinate system name and the extra fields it has. With several files, a choice A cloud for each file / One cloud of all the files. |
| 2. Classes to read | A box per class 0–18 (number and name) and Other classes (19–255). Points of classes that are not ticked are not read. |
| 3. Thinning | Read every point, Every n-th point (field Keep every) or One point per cube (field Cube size, in m; keeps the first point to fall in each cube, for an even density). The field of the method not chosen is disabled. |
The window remembers your last choice and offers it again.
The Text file columns window
Shows the file name, the separator found (spaces, tab or a character), "decimal comma" if used, and the first rows. Above each column choose its role: X, Y, Z, Red, Green, Blue, Intensity, Class, or — (not used). Import point cloud stays off, with the hint "Choose the columns of X, Y and Z, each once.", until X, Y and Z are each chosen once and no other role repeats.
If something goes wrong
| Message | What to do |
|---|---|
| Could not read the point cloud '…': … | The file is damaged, locked or in an unsupported variant; the reason follows the colon. |
| N line(s) did not read as points and were skipped. | Lines of a text file that were not numbers; check the column roles and separator. |
What next
Point classes · Thin points · Classify ground
Export point cloud
Writes the selected point cloud to a file.
Where to find it
Point Clouds tab → Exchange group → Export point cloud (Export).
How to
- Select one point cloud. If none is selected: "Select a point cloud."
- Click Export point cloud and choose the file name. The format follows the file type: LAS, LAZ, XYZ text, CSV, PLY or COPC (
.copc.laz). - The file is written in the background; on failure: "The point cloud was not written to '…': …".
Cloud from points
Makes one point cloud of the selected point objects. The cloud goes on the layer of the first selected object and becomes the selection.
Where to find it
Point Clouds tab → Exchange group → Cloud from points (Cloud from points).
How to
Select point objects and click the button. If nothing usable is selected: "Select point objects."
Cloud to points
Puts a point object at every point of the selected point cloud.
Where to find it
Point Clouds tab → Exchange group → Cloud to points (Cloud to points).
How to
Select one point cloud and click the button. Point objects are made for up to 100,000 points; a larger cloud gives "The cloud has N points; point objects are made for up to 100,000. Thin it first." (see Thin points). The points are added on the cloud's layer in one undo step.
Thin points
Leaves fewer points in the selected clouds. The thinned points replace the cloud's points.
Where to find it
Point Clouds tab → Processing group → Thin points (Thin).
How to
- Select one or more point clouds ("Select a point cloud." otherwise).
- Click Thin points and set the parameters. Click Thin.
Parameters
| Parameter | Meaning |
|---|---|
| Leave | One point per cube or Every n-th point. |
| Cube size | Edge of the cube, in m (0.001 to 1000, default 0.1). Used by One point per cube. |
| Keep every | Keep one point out of this many (2 to 1,000,000, default 10). Used by Every n-th point. |
The last values are offered again next time.
Remove noise
Finds stray points and removes them, or classes them as noise.
Where to find it
Point Clouds tab → Processing group → Remove noise (Remove noise).
How to
Select the clouds, click the button, set the parameters and click Remove noise.
Parameters
| Parameter | Meaning |
|---|---|
| Find noise by | Statistical (distance to neighbours) or Radius (neighbours within). |
| Neighbours | Statistical method: how many nearest points are compared (2 to 64, default 8). |
| Standard deviations | Statistical method: how far from the average distance a point may be (0.1 to 10, default 2). |
| Radius | Radius method: the search radius, in m (0.001 to 1000, default 0.5). |
| Fewest neighbours within | Radius method: a point with fewer neighbours inside the radius is noise (1 to 1000, default 3). |
| Class the noise as Low point (noise) instead of removing it | When ticked the points stay and get class 7 (Low point (noise)); otherwise they are deleted. |
The window notes: Statistical uses Neighbours and Standard deviations; Radius uses Radius and Fewest neighbours within. Noise points are left out of Surface from cloud and similar commands.
Classify ground
Finds the ground points of the selected clouds with a cloth simulation and gives them class 2 (Ground). The clouds are then coloured by classification, and a message gives "Ground points: N of M (P%)."
Where to find it
Point Clouds tab → Processing group → Classify ground (Classify ground).
Parameters
| Parameter | Meaning |
|---|---|
| Cloth spacing | Grid step of the cloth, in m (0.05 to 50, default 1). Smaller follows the ground closer and takes longer. |
| Terrain | Steep slopes (open pit, benches), Relief or Flat. Steep slopes need a soft cloth. |
| Ground within | How far from the cloth a point may be and still count as ground, in m (0.01 to 10, default 0.5). |
The window advises a spacing of 0.5 m or less for pit walls of 60° and more.
What next
Surface from cloud with Ground points only · Crests and toes
Normals and slope
Works out the surface normal at each point from its nearest neighbours, adds the fields Slope of the surface (degrees from level) and Direction the surface falls to (degrees clockwise from north), and colours the clouds by slope (0° to 90°).
Where to find it
Point Clouds tab → Processing group → Normals and slope (Normals).
Parameters
| Parameter | Meaning |
|---|---|
| Nearest points, at most | How many neighbours define the plane (3 to 64, default 12). |
| Nearest points within | Reach of the search, in m (0.01 to 100, default 1). A point with fewer than three neighbours gets no normal. |
| Keep the normal itself (for registration and lighting) | Stores the normal; the cloud is then lit by its normals. |
Click Work out normals. Afterwards: "Normals found for N of M points."
Align by points
Moves the selected clouds so that chosen points on them land on the places they belong. You draw two lines with the same number of vertices (three or more): one through points of the cloud, one through the target places. Vertices pair up in order.
Where to find it
Point Clouds tab → Registration group → Align by points (By points).
How to
- Select the clouds to move and the two lines.
- Click Align by points. The window Line through the clouds' points guesses which line lies on the cloud (vertices within 10 cm of its points); change it if wrong. Click Fit by points.
- A message reports the turn and shift, the root mean square miss and each pair's miss. Answer "Move the clouds?" Yes to apply (one undo step).
If something goes wrong
| Message | What to do |
|---|---|
| Select the clouds to move and two lines with the same number of vertices… | Check the selection. |
| The points on the clouds lie along one line: the turn cannot be found. | Pick points spread out across the scan. |
What next
Fine align
Fits one of two overlapping clouds onto the other (ICP, point to plane).
Where to find it
Point Clouds tab → Registration group → Fine align (Fine (ICP)).
Before you start
The clouds must already lie roughly in place, within the pair distance of each other. Use Align by points first if they do not.
How to
- Select exactly two clouds ("Select two point clouds that overlap…" otherwise).
- Click Fine align, set the parameters and click Align clouds.
- A message gives the turn and shift and the distance to the reference surface before and after (pairs and rounds). If it had not settled, "run it again to go on". Answer "Move the cloud?" Yes to apply.
Parameters
| Parameter | Meaning |
|---|---|
| Cloud to move | One of the two; the other is the reference. A cloud on a locked layer cannot be moved ("The cloud to move is on a locked layer."). |
| Pairs at most this far apart | Largest distance between matched points, in m (0.001 to 1000, default 1). |
| At most this many rounds | 1 to 500, default 40. |
Crop to outline
Keeps the points of the selected clouds inside, or outside, the selected closed outlines.
Where to find it
Point Clouds tab → Edit group → Crop to outline (Crop).
How to
- Select the clouds and the closed outlines (polylines, polygons, rectangles, circles).
- Click Crop to outline. Answer "Keep the points inside the outlines? Yes: inside. No: outside."
- The cloud keeps only those points. If none are on that side: "No points of the selected clouds are on that side of the outlines."
Point classes
Shows or hides classes of points in the selected clouds. The points are not changed, only drawn or not.
Where to find it
Point Clouds tab → Edit group → Point classes (Point classes).
How to
Select clouds whose points have classes ("Select a point cloud whose points have classes." otherwise), click the button, tick the classes to show (the point counts are given) and click Apply. The current state is taken from the first selected cloud.
Classify inside outline
Gives the points of the selected clouds that lie inside the selected closed outlines a class.
Where to find it
Point Clouds tab → Edit group → Classify inside outline (Classify).
How to
- Select the clouds and the closed outlines.
- Click the button, choose a class from 0 to 18 and click Classify.
Merge clouds
Makes one point cloud of the selected ones. The merged cloud keeps the name, layer, colour mode and point size of the first selected cloud and replaces the sources.
Where to find it
Point Clouds tab → Edit group → Merge clouds (Merge clouds).
How to
Select two or more clouds ("Select two or more point clouds." otherwise) and click the button.
Split by class
Replaces a classified cloud by one cloud per class, each named "name — class".
Where to find it
Point Clouds tab → Edit group → Split by class (Split by class).
How to
Select one cloud with classes and click the button. If all points are of one class: "The points of this cloud are all of one class."
Erase points
Erases the points inside or outside an outline you draw in the 3D view.
Where to find it
Point Clouds tab → Edit group → Erase points (Erase).
How to
- Select the clouds to erase from. With none selected the command only says what to select.
- Click Erase points to start the tool.
- Click the corners of an outline round the points in the view (three or more); a preview closes it through the pointer.
- Press Enter. Answer "Erase the points inside the outline? Yes: inside. No: outside."
- A message gives "Erased N points."
Esc clears the outline drawn so far. The outline is taken as seen from the camera, through the whole depth of the scene. Click the button again to leave the tool.
Clip box
Shows only the points inside (or outside) a box, or a slice by height. The points are not changed; closing the window shows them all again.
Where to find it
Point Clouds tab → Edit group → Clip box (Clip box).
How to
- Select clouds, or select none to use every cloud in the project ("No point cloud in the project." if there are none).
- Click Clip box. The window opens and the box is outlined in the 3D view; it starts as the whole extent of the clouds. The window does not block the program.
- Change the values; the view follows. Close the window when done.
Parameters
| Parameter | Meaning |
|---|---|
| Clip the point clouds | Switches the clip on and off. |
| Show the points inside the box / outside the box | Which side is drawn. |
| X from, X to, Y from, Y to, Z from, Z to | The box sides, in m, with − and + step buttons. |
| Slice thickness | Thickness of a slice in m. |
| Slice | Makes a slice of that thickness around the middle of the box height, over the whole plan extent, showing the inside. |
| ↓ / ↑ | Moves the slice down or up by its thickness. |
| Whole clouds | Resets the box to the extent of the clouds. |
The clipped points are also not picked or snapped to.
Surface from cloud
Makes a triangle surface (terrain model) from the selected clouds on a regular grid. The surface is a mesh on the layer Surfaces (created if missing) and is selected.
Where to find it
Point Clouds tab → Analysis group → Surface from cloud (Surface).
How to
- Select one or more clouds. To cut the surface by outlines, select closed lines too.
- Click the button, set the parameters and click Make surface.
Parameters
| Parameter | Meaning |
|---|---|
| Vertices of the surface | Grid: a vertex per cell or TIN: a measured point per cell (keeps one measured point per cell). |
| Cell size | In m (0.01 to 1000, default 1). A finer cell follows the ground closer and makes a heavier surface. |
| Height of a cell | Lowest point, Mean of the points (default) or Highest point. |
| Edge of the surface | Where the points end, Convex hull of the points or Inside the selected outlines. |
| Close holes up to | Holes up to this many cells are closed (0 to 100, default 3). Only where the surface ends with the points. |
| Ground points only | Uses only class Ground, in clouds that have it. Noise points are always left out. |
If something goes wrong
| Message | What to do |
|---|---|
| To cut the surface by outlines, select closed lines with the clouds. | Select closed lines, or change Edge of the surface. |
| No surface: too few points fall in neighbouring cells. Try a larger cell. | Enlarge the cell. |
Stockpile volume
Measures the volume of the cloud inside the selected outlines down to a base, and offers a FastReport sheet.
Where to find it
Point Clouds tab → Analysis group → Stockpile volume (Volume).
Before you start
Select a point cloud and the closed outline of the pile (one outline per pile). For a surface base, select the surface too. Without an outline the whole cloud is measured, down to a level or a surface.
How to
- Click the button, set the parameters and click Measure.
- A message gives each stockpile's volume and mass, the totals (area in plan, share covered by points, above, below and net volume, tonnage, the base plane). Answer "Open the volume sheet in the FastReport Designer?" Yes for the sheet, with a plan picture.
Parameters
| Parameter | Meaning |
|---|---|
| Measure down to | Plane through the ground along the outline, Plane through the outline's points, Level at the lowest ground along the outline, Level at an elevation, The selected surface. The first three need an outline. |
| Level elevation | In m; used only by a level at an elevation. |
| Cell size | In m (0.01 to 100, default 0.5). |
| Close holes up to | In cells (0 to 100, default 5). |
| Rock of the pile | A rock from the rock table (with density); gives the bulk density as density over swell factor. |
| Bulk density | In t/m³ (default 1.6); used when no rock is chosen. |
If something goes wrong
| Message | What to do |
|---|---|
| This base is laid along the outline of the pile: select a closed line around it too. | Select an outline. |
| Select the surface to measure down to as well. | Select the surface. |
| Too few points along the outline to lay a base through. | Use another base or a larger cell. |
Compare with surface
Colours the clouds by their distance to a selected surface (the design or an earlier survey) and reports the statistics. Above the surface is positive; points with no surface within reach stay grey.
Where to find it
Point Clouds tab → Analysis group → Compare with surface (Compare).
How to
Select the clouds and one surface, click the button, set the parameters and click Compare points.
Parameters
| Parameter | Meaning |
|---|---|
| Distance measured | Vertical (difference in height) or To the nearest point of the surface. |
| On-surface tolerance | Distance counted as "on the surface", in m (default 0.1). |
| Look for the surface within | Reach, in m (0.01 to 10,000, default 10). |
The report gives how many points are above, below and within the tolerance, the mean, root mean square, range and a histogram of the distances. The field is Distance to surface.
Compare with cloud
Colours clouds by their distance to another cloud (an earlier scan).
Where to find it
Point Clouds tab → Analysis group → Compare with cloud (With cloud).
How to
Select two or more clouds, click the button, choose which one to compare with and click Compare points. The others get the field Distance to cloud and the same report as Compare with surface.
Parameters
| Parameter | Meaning |
|---|---|
| Compare with | The reference cloud. |
| Distance measured | To the nearest point of the other cloud (no sign) or Vertical, to the other cloud's surface (above is positive). |
| Look for points within | Reach in m (0.01 to 10,000, default 5). |
| Cell size | Grid of the other cloud's surface, in m (default 1); used by the vertical method. |
| On-surface tolerance | In m (default 0.1). |
Section along line
Makes a profile polyline of the clouds along each selected line, and optionally a cloud of the points in the strip.
Where to find it
Point Clouds tab → Analysis group → Section along line (Section).
How to
Select the clouds and the lines, click the button, set the parameters and click Make section. Profiles go on the layer Sections (created if missing). If nothing is within the section: "No points of the selected clouds are within the section."
Parameters
| Parameter | Meaning |
|---|---|
| Section width | The whole strip across the line, in m (default 1). |
| Profile step | In m (default 0.5). The profile breaks where points leave a gap of more than three steps. |
| Height of a step | Lowest point, Mean of the points, Highest point. |
| Parallel sections on each side | How many extra lines on each side (default 0). |
| Spacing of parallel sections | In m (default 10). |
| Ground points only | Uses only class Ground. |
| Also make a cloud of the points in the section | Adds a copy of each cloud named "name — section" with only the strip's points. |
Crests and toes
Traces the crests and toes of benches on the selected clouds or surface as polylines, on the layers Crests and Toes.
Where to find it
Point Clouds tab → Analysis group → Crests and toes (Crests).
How to
Select the clouds (or a surface), click the button, set the parameters and click Trace edges. A message gives "Traced N crest lines and M toe lines." Check the lines: spoil heaps and ramps make edges too. If none are found: "No bench edges found: try a gentler face slope or a smaller cell."
Parameters
| Parameter | Meaning |
|---|---|
| Cell size | In m (0.05 to 100, default 1). |
| Face from a slope of | A cell steeper than this is face (5° to 85°, default 40°). A crest is where a bench lies above a face, a toe where it lies below. |
| Straighten lines within | In m (default 0.3). |
| Leave out lines shorter than | In m (default 10). |
| Ground points only | Uses only class Ground. |