topic Re: Modeling a terrain (solid, not a mesh) with a soft surface in AutoCAD Forum

Modeling a terrain (solid, not a mesh) with a soft surface

teocruz105 — Sun, 03 May 2020 17:21:15 GMT

Hi,

I need to model a solid terrain in autocad. I created the level curve in AutoCad 2020. Then, I imported the file to Autocad Architecture and create a mesh, with a very good looking surface. Since I need the terrain as a solid, I converted the mesh into a solid and imported it back to AutoCad 2020. The issue is that the solid had a very bad surface when I imported it and delete the polylines. And it looks veven worse when I convert the file to an STL. How can I create a terrain in AutoCad with a very nice furface, but still a solid?

Re: Modeling a terrain (solid, not a mesh) with a soft surface

j.palmeL29YX — Sun, 03 May 2020 17:52:09 GMT

Can you post the files (the mesh, the solid) here?

And maybe two images (poor quality, good quality).

Re: Modeling a terrain (solid, not a mesh) with a soft surface

Alfred.NESWADBA — Sun, 03 May 2020 18:31:57 GMT

Hi,

>> looks veven worse when I convert the file to an STL

Try to set FACETRES to 10 (default value is 0.5), then run command _REGEN ... better? (also the export to STL is more fine).

>> How can I create a terrain in AutoCad

I would use Autodesk Civil 3D, depends on if you have access to it.

- alfred -

Re: Modeling a terrain (solid, not a mesh) with a soft surface

teocruz105 — Sun, 03 May 2020 19:16:06 GMT

Here you have the file as a mass, I convert it to a solid and the surface does not look good. If I use the command Smooth, it will become a mesh...but I need it as a solid and looking well. I have attached a stl file as well.

Re: Modeling a terrain (solid, not a mesh) with a soft surface

Alfred.NESWADBA — Sun, 03 May 2020 19:02:22 GMT

Hi,

[EDIT]deleted[/EDIT]

- alfred -

Re: Modeling a terrain (solid, not a mesh) with a soft surface

teocruz105 — Mon, 04 May 2020 00:25:05 GMT

Yes, I did. I set it to 10 and then I did a regen, but it remain more or less the same.

Re: Modeling a terrain (solid, not a mesh) with a soft surface

j.palmeL29YX — Mon, 04 May 2020 02:50:17 GMT

@teocruz105 wrote:

Here you have the file ...

I have attached a stl file as well.

No attachments here 😕

Re: Modeling a terrain (solid, not a mesh) with a soft surface

teocruz105 — Mon, 04 May 2020 16:04:02 GMT

Sorry, here are the attachment. As I said before, I need to have this terrain as a solid, with a smooth surface. When I converted to a solid, and erase the original mesh, aspect of the surface changes. And that aspect is the one I will see as a stl file, too. If I select "No" to erase the original mesh when converting it to a solid, it will look fine, but that is only because the mesh is still covering the solid. But when I export it to stl, only the solid will be converted, so the aspect will look bad. I have attached a stl, too.

Re: Modeling a terrain (solid, not a mesh) with a soft surface

j.palmeL29YX — Mon, 04 May 2020 18:20:01 GMT

@teocruz105 wrote:

... and erase the original mesh,

Can you upload the "original mesh" too?

Re: Modeling a terrain (solid, not a mesh) with a soft surface

teocruz105 — Mon, 04 May 2020 19:10:45 GMT

Here it is...the file with the original Mesh

Re: Modeling a terrain (solid, not a mesh) with a soft surface

j.palmeL29YX — Tue, 05 May 2020 13:11:15 GMT

@teocruz105 wrote:

Here it is...the file with the original Mesh

Aha. Your "Mesh" is an AEC_Mass_Element. That's a completely other world.

I'm not familiar with those products, but I guess, this Surface only LOOKS good, the VISUALISATION is smoothed, but intern it is modeled always as a lot of small triangles. (maybe someone will correct me).
To get a smooth AutoCAD-3DSolid, you must create a smooth modeled element.

In the attached dwg (coming soon, 100+ MB) I did this:
- Explode the AEC-object to get a 3D-Solid
- Slice the 3D-Solid into small disks
- Extrakt the upper conture of this disks as Splines
* Xedges command
* Delete all not needed lines
* join the lines of the upper contoure to a polyline
* Smooth the polyline (pedit -> spline)
=> result a bunch of Splines (green)
- create a lofted surface using this splines.
- create a box and slice the upper part of the box using the lofted surface
=> the yellow 3DSolid.

To improve the quality of the Loft may add some splines to use as Guides (here 3 blue splines).
=> the red 3DSolid.

I know this involves some effort, but perhaps it will help to achieve the desired goal.

If my reply solves your problem, click the "accept as solution" button. This can help others find solutions faster.

Re: Modeling a terrain (solid, not a mesh) with a soft surface

j.palmeL29YX — Tue, 05 May 2020 14:08:17 GMT

... and >>here<< the missing file.

Re: Modeling a terrain (solid, not a mesh) with a soft surface

teocruz105 — Tue, 05 May 2020 15:47:53 GMT

Thanks for the suggestions. I seems autocad does not have an easy way to do this. I'll keep trying this steps. If I solve it this way, I'll post it here.