How to create spline outline around mesh?

[darawork]

Hi,

I have a road in 3DSMax 2019 that has come in from AutoCad. It started life as a 3D solid.

When I brought it into Max I Freeform conformed it to some terrain contours. Unfortunately, after the conform process it now has no thickness.

As you can see from the pictures attached, the mesh is not at all optimal for an Edit Poly extrusion process, it makes Max hang.

So now I want to outline the mesh with a new closed spline that I can extrude afterwards, into a nice low poly Quads surface.

How can I do this? See the second picture, Unwrap UVW makes a nice outline, that would be prefect if I could just keep the outline.

Any help? 

Thanks 🙂

Non optimal road meshNice outline from Unwrap UVW

[PROH]

Hi darawork. Since your road now is collapsed close mesh with sides without hight and top and bottom at the same place, I really can't see any automated way to do this.

Unless your road got different mat IDs for top, sides and bottom, I would do this:

- select your road and in its object properties set "Backface cull" to on.

- in the editor (mesh or poly) activate face or poly and check "ignore backface".

- go to TOP view an select the top faces with the cursor.

- when done invert selection and delete

- check if there's still some unwanted "sides". If so delete them.

Now you should be able to generate an outline by "select open edges" or "border".

Hope it helps

[darawork]

Thanks for the suggestion Proh,

I'll give it a go tomorrow. I have deleted the original bottom faces already so as to avoid flashing normals in an animation we are doing in Lumion. So I can view the bottom view perhaps instead, and continue with the steps. My screenshot is just a small section of the roads, that's about 1/10th of the entire network. Clicking individual faces all the way around is not ideal, nor fun. 

It's just a bit annoying that I can see the lovely clean seam outline in green with the Unwrap UV modifier, but can not figure out a way to extract the seams from that process. The seams are varying in Z-Value too, so it would be really handy to grab the results and make a very low poly version of the roads. That's what I'm aiming for ideally; a low-poly version of the whole site. I've tried Pro-optimising the roads, but Max locks up calculating the result. Batch Pro Optimise works to create varying percentages as separate files, but they are not as nice as if I was just to create the mesh in Max originally.

The roads having come from AutoCad 3D solids means that there are no 'Border' sub-elements there either.

I think MAYA can do all of this in one click. 😞

[PROH]

Hi. Hmm... not sure I fully understand what you're saying. If you deleted the bottom faces, then there should be a "border" or "open edge" (depending on what kind of mesh you have). If that's not the case, then this would mean that your mesh is doubled and closed OR that you are working with Body-objects. If the last is the case, them why not convert it to edit poly?

Regards