How to fill "holes" in a surface?

[JamesMaeding]

I understand that civil3d has contraints, and all kinds of things that would cause triangles to not appear.

That is not my question here.

I have the situation where I import a landxml, and its missing triangles here and there.

Its not a bad landxml, they are literally missing from the triangle list so civil3d did it right.

How would I "fill" those though?

My first thought was to generate the 3d edges of the holes, and add those as breaklines.

I generated those, and added but C3D never finished thinking once I did that, it hung.

So that approach is bad, likely because I think c3d treats tri edges in a landxml as all breaklines.

You add one, and it seems to think forever (300k tri surface in my case).

My answer is pull that landxml into other software and fill and re-export the landxml.

That is no good for my buddies who only have civil3d though.

BTW, filling a hole means making a surface from the edges and adding the tris from that.

Could be a single triangle hole, or a huge missing area with 500 edges forming its boundary.

thanks,

[Neilw_05]

Rather than creating and adding breaklines, I suggest using the Add Line tool in the Surface Editing tools. It should form new triangles as you go.

[Jeew-m · Accepted solution]

This video has a lot of data related to fixing holes in a surface.

[Neilw_05]

Nice techniques JEEW. Never thought of adding then deleting points. Works nicely. Learned a new one today.

[JamesMaeding]

@Jeew-m 

Interesting. That is rather one by one so not quite my situation.

I've got hundreds of these going on.

Having said that, I could easily calc the centroid of each hole and make a list of pts to add to c3d.

I'll try a few things.

thx.

[Joe-Bouza · Accepted solution]

Have you tried a show boundary

[JamesMaeding]

@Joe-Bouza 

Yes, and that does work. I was thinking it was one by one, but actually the import objects let's you do crossing window.

Then I thought more, and heck, import all and erase the big outer.

Add those as shows and it's done.

Very good, I'll call that a solution!

[Neilw_05]

There should be borders around the holes. If so, you could just extract those from the surface and use them as show boundaries.

I agree, Joe has a great solution.

[Joe-Bouza]

I was thinking a show boundary around the entire surface

[Neilw_05]

Brilliant.

[Joe-Bouza]

Thanks. I have done it with success.

[JamesMaeding]

@Joe-Bouza 

Your tagline mentions c3d 2018. The big jump in ability for us was how 2019 handles windows high dpi issues much better than 2018. Beyond that, I think in 2020, they added a button back that they took away in 2019, break even 🙂

[Joe-Bouza]

Thanks. we are ramping up to 2022 soon