Working for an Autodesk reseller has its advantages. We were recently gifted with some cloud tokens to test what are the square flows that cost money to compute online.

One workflow that often is discussed within the industry is the generation of a mesh from point clouds. A typical example of this would be in a mine where the mine shaft is scanned and where equipment must be fitted during an automation drive. Generation of shaft elements poses a challenge in some 3D because Civil 3D cannot generate surfaces that overhang. Usually, the roof and the floor of the shafts are constructed as surfaces while their sides are either left out or modelled as some other vertical element.

One of the advantages of a mesh file is that one can clash detect it against other 3D models. One cannot clash detect using a point cloud.

While I do not have mine data that I can share, I can share data from my bicycle which I recently modified. Note that I do not have a laser scanner (which can give sub-millimetric accuracy) or even a high-definition camera. I used a Samsung A315 12MP mobile phone camera in this exercise. The thinking is that the pipes of a bicycle could represent a mine at scale.

The idea is to take photos from various elevations and angles and to use the best image resolution camera available to you.

Open Autodesk Recap Photo. One of two options exists to create a new 3D Project. Aerial and Object. Aerial can generate a point cloud in addition to a mesh, while Object only generates a mesh. Aerial also typically expects a georeferenced image, but if none is available you can go ahead anyway albeit with questionable results.

Choose to create the project with the images taken of the object Using the Object method. I simply took some photos with my mobile camera with the bike propped up between two chairs in the living room.

Hit the Create button.

Choose a project name and save it to the cloud. Note that 4 cloud credits are needed to create the necessary files.

It might take a while to upload the images.

Then your model might wait in queue for a while before it is processed

For comparrison and to have a point cloud available to me, I also create a project usign the Aerial method. Again, 4 cloud credits are needed.

You are notified when the project is ready via email.

The Object (420.8 MB) method results in a much better mesh file than the Aerial (19.5 MB) method. After deleting the parts of the mesh that is not needed, the file looks like this.

Compare this to the point cloud that was generated from the Aerial method. Perhaps the most irritating thing is that the point cloud is not displaying with the correct orientation. I suspect this is because the photos are not georeferenced.

Nevertheless, after some manipulation I managed to insert the point cloud into the DWG I am using to design the bicycle modifications.

Viewed from further away one can see that one might be able to do something with the cloud. It is still an improvement on measuring with a measuring tape, and my initial design would have been more accurate. I eventually hand-crafted the carrier into position and sacrificed handling stability for having the ability to carry bigger loads – the center of gravity of the load is behind the back wheel now.

A better way to generate the point cloud is to export it as a PTS file from the Object method mesh.

Then import that into Recap as a point cloud.

Here is the more detailed point cloud shown in AutoCAD.

One of the questions I have been asked how to get a scan to mesh file into AutoCAD. This is not as simple as it seems because AutoCAD does not import FBX and OBJ any longer, so one must work through a program like Autodesk 3ds Max to export the mesh to DWG. In this case, The Shaded OJB is shown. It appears rather inaccurate.

Also, not the number of facets on the mesh when viewed in wireframe.

When the export to DWG is completed, it results in an empty file, signifying that the export to DWG failed and we cannot therefore work with the mesh in AutoCAD.

If you need a step-by-step instruction to create a mesh from a point cloud, please watch this video.

If you need help adopting the AEC Collection or the Autodesk Construction Cloud in your practice or you are looking to invest in hardware, please contact Micrographics so that we may be of assistance.

Still looking for answers? Start a discussion with other professionals in your industry!