You signed in with another tab or window. Reload to refresh your session.You signed out in another tab or window. Reload to refresh your session.You switched accounts on another tab or window. Reload to refresh your session.Dismiss alert
Copy file name to clipboardExpand all lines: tutorials/point_cloud_to_mesh.md
+12-12Lines changed: 12 additions & 12 deletions
Original file line number
Diff line number
Diff line change
@@ -21,7 +21,7 @@ After installing, open CloudCompare and import your point cloud file by going to
21
21
Depending on the number of points in your point cloud, this could take several minutes.
22
22
Once loaded, you should see the following tunnel section:
23
23
24
-
24
+
\image html files/point_cloud_to_mesh/cloudcompare2.png
25
25
26
26
Many 3D scans will be composed of millions, sometimes hundreds of millions of points.
27
27
Converting a scan to a 3D model with that many points would be very difficult due to the number of polygons that would be created and the long processing time necessary to compute the normals.
@@ -35,21 +35,21 @@ We'll still walk through reducing points, however, to make the process quicker.
35
35
36
36
To reduce the number of points in your cloud, click on the tunnel so a yellow cube outline appears around it, then go to `Edit` > `Subsample`.
37
37
38
-
38
+
\image html files/point_cloud_to_mesh/min_space.jpg
39
39
40
40
The number you will need to enter in the `min. space between points` field will vary depending on your point cloud.
41
41
A value of .01 was sufficient to bring our point cloud to an easy-to-manage 1 million points.
42
42
Point count is visible in the `Properties` window on the lower left side of the screen.
43
43
44
-
44
+
\image html files/point_cloud_to_mesh/properties.png
45
45
46
46
How many points you reduce down to will largely depend on how long you are willing to wait for the point cloud to be converted into a mesh.
47
47
The more points you start with, the longer it will take to compute the normals and create the mesh.
48
48
49
49
After the operation is complete you’ll have two clouds in your scene: the original point cloud and your subsampled point cloud.
50
50
Most operations in CloudCompare will create new point clouds and keep the original, so make sure that you have the new point cloud selected before running an operation.
51
51
52
-
52
+
\image html files/point_cloud_to_mesh/secondcloud.png
53
53
54
54
### Create a Polygonal Mesh
55
55
@@ -60,7 +60,7 @@ A normal is essentially the direction a polygon is facing.
\image html files/point_cloud_to_mesh/compute_normals.png
64
64
65
65
You’ll see various options in the dialog box that appears.
66
66
The main thing you’ll want to consider is what `Local surface model` to use.
@@ -73,7 +73,7 @@ Now we get to actually convert our point cloud to a mesh.
73
73
To do this go to `Plugins` > `PoissonRecon`.
74
74
You'll see this dialog box:
75
75
76
-
76
+
\image html files/point_cloud_to_mesh/outputdensity.png
77
77
78
78
The value you enter in the `Octree depth` field will determine the polygon count of the created model.
79
79
You may have to run the surface reconstruction a couple times with varying values before you land on a polygon count that is suitable for your needs.
@@ -94,18 +94,18 @@ Our tunnel has turned into a blob shape.
94
94
This is because the mesh that CloudCompare creates will always be water tight even if it has to add polygons where there are no points.
95
95
We just want our tunnels, though, so we need to remove those unnecessary polygons.
In the mesh's `Properties` window go to `SF display params` and take the left handle in the graph and drag it to the right until it hits the area where the bulk of the scalar field starts.
\image html files/point_cloud_to_mesh/sf_display.png
103
103
104
104
This will display only the polygons that were created from the point cloud and hide the polygons used to make the model watertight.
105
105
The polygons are only hidden however.
106
106
We still need to actually remove them.
107
107
108
-
108
+
\image html files/point_cloud_to_mesh/hidden_polygons2.jpg
109
109
110
110
To remove the hidden polygons go to `Edit` > `Scalar fields` > `Filter By Value`.
111
111
@@ -114,11 +114,11 @@ Hitting export will simply export the mesh within that range.
114
114
Instead, we'll hit `Split` to create two meshes.
115
115
One with the polygons inside our specified range and one containing polygons outside that range.
116
116
117
-
117
+
\image html files/point_cloud_to_mesh/split.png
118
118
119
119
It is possible that you will get error "Visibility table not instantiated". This error causes only the "wanted" part of the mesh to be created when splitting, while the other ("unwanted") part will not be generated. But that is not a problem for our use-case.
120
120
121
-
121
+
\image html files/point_cloud_to_mesh/error.jpg
122
122
123
123
### The Completed Model
124
124
@@ -128,6 +128,6 @@ Your file format will depend on the software you want to use but `.obj` is a wid
128
128
129
129
Before exporting, check your mesh for holes. If still checked, disable display of the pointcloud, so that only your output mesh is shown. Inspect ground parts of the mesh (or any other parts you are most interested in) and check if there aren't holes in it. If there are some, you can try to repeat the trimming step with more relaxed threshold.
\image html files/point_cloud_to_mesh/complete2.png
132
132
133
133
You can find more information on CloudCompare and a more in depth look at the tools we used in this tutorial on [the CloudCompare website](https://www.cloudcompare.org/) and the [CloudCompare wiki](https://www.cloudcompare.org/doc/wiki/index.php?title=Main_Page).
0 commit comments