topic Converting 3d Scans into models in Fusion Design, Validate & Document Forum

Converting 3d Scans into models

Anonymous — Sat, 24 Nov 2018 02:55:18 GMT

I have been messing with some scans for about a year and have yet to come up with a practical solution so I thought I would ask the community.

My machine shop fabricates some forms for making kydex holsters. These look like aluminum handguns that are split in half, with many holes drilled in them, they are attached to a flat plate and placed on a vacuum table which forms the hot kydex into the desired shape.

The manufacturer I make these forms for customizes their holsters (a lot), so I am constantly reworking them to add lights, accessories or some modification to suite the customer.

Initially, we scanned the base weapon, and intended to turn those into models that could be modified to suit us. I've attached a screenshot of a scan of a Glock 17. The scans are very high quality which is part of the issue since converting them directly fails since the number of facets is too high.

I also do not need the detail that the scans provide; for example, some of the textures are irrelevant, but the details of the trigger guard are very important.

I am trying to understand a strategy for transforming these scans in to something I can work with. I have viewed many of the mesh design tutorials and have a basic idea of how to do what needs to be done, but I thought I'd ask for some opinions about which methods might work best.

The first problem I have been having is figuring out how to get into the sculpt or mesh environment after the latest update to the menu bar. I have stumbled across it, but can't seem to find it when looking for it.

Once there, I like the idea of pulling t-spline planes to the surface and then aligning them with an axis for the flat areas, but that seems inefficient. Creating a loft of the profile also seems workable. Point is that there are a number of ways to do this, and I would like to come up with a procedure for my company that will improve efficiency. By the way, that includes a scanning technique. Do we use high resolution or low resolution? Does converting to quad help? etc,etc.

Any help or suggestions would be appreciated, but in the end, it must be modifiable. Almost everything I have looked at so far is very difficult to modify the timeline (if one exists) to make small adjustments for different holster models. Although it is a different model, I have also included a screenshot of one that was completed, however it was manually drawn without a scan. I can provide the STL of the scan if that helps, but it's pretty big, so I would probably need to share the Fusion 360 project file.

Thanks in advanced,

Robert

Re: Converting 3d Scans into models

laughingcreek — Sun, 25 Nov 2018 02:54:36 GMT

Fusion isn't particularly good at editing mesh models. (understatement) I've done similar things to what your describing using mesh mixer. My work flow is something like this-

-import mesh onto fusion

-create and position solid modifications in relation to the mesh (visually)

-export it all to mesh mixer

-use mesh mixer to combine and blend, add thickness etc.

I like mesh mixer (free). It can do a pretty amazing array of things to a mesh. But there are other mesh editors out there that will work also. Pick your poison.

I don't bother trying to convert the original mesh to anything in fusion. much darkness lays down that path. I just use it as a visual reference. (visually close is usually good enough for this type of thing).

If you can get a good quad mesh from the get go, It may be worth it to import a low res version of that and see if you can work with it. (Make sure triangulate meshes in preferences is NOT checked.) .

Re: Converting 3d Scans into models

jodom4 — Mon, 26 Nov 2018 18:32:54 GMT

Hey bobKP8AA,

The most important thing with this workflow is to convert your triangulated meshes into quadrangulated meshes. Tri-meshes don't play well with solid conversion- they make for large, messy bodies. Quad meshes result in smooth, rational bodies that will be much easier to work with.

Here's a youtube video that might be helpful:

Re: Converting 3d Scans into models

Anonymous — Fri, 30 Nov 2018 19:34:56 GMT

Hi Jon,

I found and viewed that email and tried converting into quads, but couldn't get either method to work. The stl files seem fairly clean, but they have a lot of facets. Do I need some preprocessing before converting?

Re: Converting 3d Scans into models

I_Forge_KC — Fri, 30 Nov 2018 19:50:56 GMT

InstantMeshes is a fantastic open-source (free) tool for the conversion to quads. It has the ability for the user to influence the topology quality by "painting" contours, which results in superior retopology over purely automated functions.

Some food for thought.

Re: Converting 3d Scans into models

Anonymous — Sat, 01 Dec 2018 03:57:43 GMT

InstantMeshes seems like a nice tool. I converted a 1911 Magazine to a quad mesh with it and uploaded that to Fusion 360. So far, so good; now I am trying to edit the mesh and can't find any way to edit the mesh in the new update of Fusion (although I noticed that a new update is downloading). I'm guessing that I'm missing a setting.

Re: Converting 3d Scans into models

I_Forge_KC — Sat, 01 Dec 2018 04:07:29 GMT

Mesh editing in Fusion is... Well...

Go ahead and convert that to TSplines so that you can work with it. You may also want to turn on the pure quad setting in IM to get rid of the triangles which can cause issues.

This is a fairly simple model, so you can tinker and see what's what. In reality, this is pretty orthogonal (cubic) so you could probably remodel from scratch with the mesh as a "guide" with much more fidelity, controllability, and personal sanity.