I'm new to Fusion 360 and still getting nowhere. Mesh this time....

[Anonymous]

I've given up on the idea of importing a dxf of a 2D representation of a boat hull from freeship because it became abundantly clear that it was simply not possible to manipulate the 'lines' to create a 3D frame to work on.

So instead I turned to a 3D mesh, from Freeship, same hull, successfully opened as a file in Fusion 360. I then watched a video that showed how to create a mush section sketch. Great. Only one ENORMOUS issue. What ever I do, I simply cannot select the mesh so any functionality that we might pretend exist in those tutorials does in fact not exist. 

I am determined to actually create an image of the hull that I can get to a 3D printing stage. but so far after a week of trying to achieve even one step I have been thwarted by an application that so far is proving totally useless.

I am happy put the file up with the mesh in it, but because of the total confusion I find myself in, I cannot even find somewhere in the app that tells me where the files are stored.

I am a windows user of decades using many many apps, including Cad and I have never come up against such an awkward app as this

[jeff_strater]

Ship design is not an easy topic.  In my view, you are right to abandon using the DXF approach directly.  However, using a mesh is not the answer.  Fusion is not a mesh design tool.  You can do basic things, but starting from a mesh model of a ship would most likely not lead to success, unless you do not want to make any modifications.  I would do a search here for some relevant threads.  There seem to be a lot of folks here that are attempting what you are also attempting.  Here are just a few:

• slow-performance-and-using-components (ignore the title, it is all about ship design)
• lofting-a-ship-planking 
• ship-hull-from-frames-issue 

If the DXF files are useful, I would be tempted to use those, but convert them to construction geometry, and re-fit native Fusion splines to those DXF curves.  Then, use Loft to create the ship hull.  But, there are lots of ways to do this.

[davebYYPCU]

If you can get the mesh model into Fusion, way better than those DXFs.

I can use the mesh section process with success, need to see what you have done so far.

More importantly, why doesn’t the mesh, print?

[Anonymous]

It's been an interesting few evenings, continuing to try move forward with Fusion 360. I’m being very positive.
By trial and error, I found the mesh export came to the app by File Open quite successfully and a I spent time reading and watching videos on how you could (because there are menu options existing) create a slice through a mesh that enables reverse engineering. This would have been a very good solution. I watched, repeated the task, watched again, repeated again, but in my real world it does not work. It is simply not possible to select the mesh in the tool provided. Another dead end. Maybe it is because the mesh isn't closed. i,e the hull form is open, not a spanner or arm for a fictitious robot part.. Technically though, it is a mesh, it should have worked. I tried to read supposed solutions but too clunky, none sensical, and none of it works.
Then, looking the mesh I decided to have a go at creating form faces in a 3D view to build a few ribs, or splines, or whatever you want to call them. They are in the file I have enclosed, and you can see I used them to build faceted faces on a little model. This was quite successful given that it is not possible to click (snap-to) to a guaranteed point on the mesh.
Working in the 2D plane was poor with the coordinates randomly flicking between one plane and another as attempted to sketch. Another nonstarter.
So, at this point I am, in a fashion, creating approximate rib sections that give something to form a hull shape on. It is a somewhat faltering start.
Then I tripped over the ability to convert the mesh to a forms ‘body’ and this means I have a 3D collection of faces of the hull, which can be edited, so now have the ability to to snap to face edges. I am, for the first time actually achieving something.
But what about fine tuning the imperfect mesh/body that was imported. Yet another mind-boggling lack of functionality. The 3D co-ordinates are only available in a relative sense. So you don't know where you are starting from: 0,0,0 (not the actual location), so you don't know where you are going.
There is nowhere to put in an absolute destination x, y, z. On my mesh/body I can see anomalies caused by the way I built the 3D model in Freeship, but I cannot fix them because I do not seem to be able simply say I want this point at x=1000, y=10,000, z=2,000
There is the inspect tool which will give you absolute reference points and will compare one location to another, but what use is it? Without giving the ability to use those figures to specify the absolute position of X, Y, or Z, and then the relative location of other points around the fixed coordinate is pointless. In my case I see a mistakenly concave hull section but am powerless to fix it in a controlled way.
It might be Autodesk wants me to find the table of reference points and start amending them manually in a character-based or spreadsheet way. I find it hard to believe that this is necessary. This for me is an artistic pursuit, I want to print off what I think is an ultimate form. I do not see my needs are anymore than any designer in this supposed ‘Top down’ topology. I mean, would not any manufacturing, architectural, print, or reverse engineering process want to know and use precise coordinates to work from.
There are tools I have been using in the Fusion 360 UI like 'straighten' which only goes to prove the point that straightening is only as good as knowing where the first and last point you want to straighten between are. I see there might be add-ons that people have created for the numerous people who have asked the same question, but I can bet they will not work with the 'Forms' module.
So. Am I wrong? Can I reference and address fixed coordinate points? nor am about to try straightening edges by visual sight in a 3D perspective view of a model, point by point?

[davebYYPCU]

You did not say why the freeship model does not print.

if you moved to Italy, would you learn to speak Italian?

Your dxf, Data is the Italian dictionary.

Form objects are approximations, 

dxf files have coordinates.

creat mesh section, cuts mesh bodies to reverse engineer mesh models.

There is no easy button, in Italy.

Fusion will make your model, with Fusion (Italian) curves.

Learn to use Fusion, with dimensions from the dxf, 

Said without access to the model yet, back later when I have reviewed you file, and send back an example.

[davebYYPCU]

Couple of surfaces to show it can be done.

Large black dots in the sketches are projected points out of the dxf.

Might help....

[jeff_strater]

Thanks for sharing the model.  A couple of points to bring up:

• This is a quad mesh.  This is both an advantage and a disadvantage.  The advantage is that you can automatically convert it to a T-Spline (Form) body.  The disadvantage is that the Mesh Section tools only operate on triangle meshes.  It's a good thing to familiarize yourself with the different body types in Fusion, as this is critical to understanding the geometry involved, and in moving forward:
  • triangle mesh
  • quad mesh
  • Form (T-Spline)
  • Surface B-Rep
  • Solid B-Rep
• This is a very small quad mesh.  The entire ship is 11mm end to end.  Probably this is a units issue (what units is the imported design in?)  Maybe you need to just scale the mesh after it is imported
  
• The quad mesh here has some issues - the resulting T-Spline has a few errors:
  • some topology problems - as suggested by the error, these can be repaired by Repair Body
  • Even after the repair, the resulting T-Spline has some self intersections.  In the screencast below, I did not attempt to fix those, just deleted some bad faces - you would have to do a better job

But, this is one way to move forward with the mesh that you have.  There may be other ways to work with the data you have, as well.  If you want to use Create Mesh Section, you would have to convert the mesh to a triangle mesh, by turning on this preference:

screencast: