Wrap-around Project to surface

[Anonymous]

Hi,

    I'm trying to wrap an 'M' shape around a simplified body (a cylinder) and I'm not getting the results I was expecting. Firstly, not only is there a front projection, but there is one from the back and secondly both projections have merged (as well as producing some spurious points).

    When I did this with a smaller object to be projected that didn't have wrap around, this worked fine and I could simply delete the back copy, but things are more complicated with a wrap around situation and I don't know how to untangle them.

In the corners of the M (the circles) I want to drill holes into the cylinder so the wrapping will help me know where to pre-locate the holes. I'm quite new to Fusion 360 so your help and guidance is appreciated, whether it is how to turn off the back projection or a better way of skinning this cat.

Sincerely, Paul.

[Anonymous]

Hey there @Anonymous

I'm not an expert with Fusion, only been using it for a month or so, but I'm going to try and help you, maybe what i'm thinking works.

I'm not sure if you plan to extrude the M from the cylinder, I would assume so. If you are, I would approach this in three different ways:

1. if you don't want the projection on the back, Instead of using the cylinder primitive, I would make two splines, one for the back and one for the front, and extrude them in the Patch work space. This will give you two surfaces (back and front). From there you can try to thicken them so they become solid bodies and then try to project your spline only to the front. After that you can do what's needed to make everything a solid body again.
2. you can also select your M profiles and use Extrude in the model work space and in the call out you can select to extrude from another face, you can try selecting your body and extrude. You avoid the step of projecting the sketch to the surface.
3. Maybe you can split the cylinder primitive in half and then do the same projection to the front body only, this is probably the easiest way. 

If you share your scene I can give it a shot and see if any of my solutions work for your needs. Always eager to help.

[TrippyLighting]

There's not really a good wrap function in Fusion 360, but you can "cheat" brilliantly with the sheet metal tools.

Design is attached for study.

[Anonymous]

Thanks Peter,

    Your example looks perfect, unfortunately my cylinder was a trivialized example. My real equivalents as high density meshes of Bones that can't be unrolled like a cylinder. I'd looked at the sheet metal tools briefly a few days ago, but figured I'd only get a very rough approximation if I had to manually extrude and flange/fold my way around the surface. One advantage is rather than designing the 'M' shape and wrapping it and seeing where the screws need to go I could instead place the screws optimally and reverse back from that what the 'M'-like shape should look like when the sheet was unrolled.

   Thanks for the post, you've given me some more incentive to dive deeper into the sheet metal working tools...

Sincerely, Paul.

[TrippyLighting]

For that sort of "wrapping" what you really are looking at is UV-unwrapping, something that Fusion 360 does not offer, but is natural to many Sub-D modeling software packages.

Also, as you are working with high density meshes, you should consider re-topologizing the bone and work with the surface derived from that. There's also a chance that you might be happier with a tool like Meshmixer, which handles such meshes much better than Fusion 360.

However, the application you are somewhat hinting at is vert interesting. Could you elaborate on what exactly you are trying to accomplish ?

[Anonymous]

Hi @Anonymous,

    Thanks for the response =). I've attached the .F3D file in case you feel like having a tinker with the file. I was trying to avoid variations that required splitting the object into a front and a back as I know the wrapping object will extend past half way so I would clip the wrapping (as far as I can tell). The Cylinder was just a simplified example. The more complex example I'm working with is more organic in nature (bone).

    You can see I also had another problem in that the wrapping shape was disappearing between the two bones so I had to make a loft between them from nearby perpendicular cross-sections and then fusing the whole thing together. The wrap around polyline looks better than it started only because I started manually deleting the duplication at which point I figured my time was better spend hunting for some people smarter in this program than I =).

    If you come up with a nice process I'd love to hear it =).

Sincerely, Paul.

[Anonymous]

@Anonymous

The file you sent is just the cylinder. I wonder if it might be worth it to get a cylinder from the sculpt environment, try to wrap the M to it and extrude, and then use the pull function in Sculpt to make it conform to the shape of the bone.

Otherwise I think @TrippyLighting is absolutely right. What you are trying to achieve would be done in UV mapping with a displacement texture

[Anonymous]

Peter,

     The UV-unwrapping is a good idea also, I'll have to try it out. The nice thing is I could optimally place the holes in the bones, unwrap it and then trace the paths between the bones while the surface is unwrapped. I know that a straight line while unwrapped will produce a curved surface while wrapped which i'm not sure will be good or not, but its something to tinker with =).

    I installed Meshmixer at the same I did the Fusion 360 trial and have only used it to down-sample a correct mesh mistakes before importing it into Fusion 360 otherwise it ground to a halt from the mesh density. Once I got it imported I figured I'd try and stick to the one tool and I'd heard good things about Fusion 360, but the learning curve with these things is always so high, but worth it (eventually).

    I'm working on synthetic custom designed ligaments...

Sincerely, Paul.

[Anonymous]

@Anonymous,

    Sorry about that. I hadn't exported before and forgot to check the file before sending it. It figures that it only exported the Highlighted item now that I think about it. I've attached another, see if this is better. I'm still getting used to the different environments, but pulling from the cylinder to the bone surface sounds interesting. I'll give it a try and perhaps post a file with some bone data also.

Paul.