Frustration from CAD site plan to sketchup workflow

[suace]

To achieve an accurate context for a model, I tend to import the civil site plan for the project to grab curbs, roads, sidewalks, etc. This allows me to drape the drawing on to the geolocated site and extrude these site details without having to redraw the entirety of the site plan in sketchup. This is usually my end result, and what I am currently trying to achieve with this new project.

On previous projects, there was some major cleanup involved with preparing the cad for import and cleaning up the lines in sketchup. This time consuming cleanup was solely done to fix the issue of apparently closed shapes not forming/cutting surfaces on the draped terrain (1), a common issue from a cursory read of this forum.

Now, I am having an issue with previously curved polylines/arcs in autocad not draping on to the surface (2). (If anyone has a suggestion on how to prep curved polylines in cad to import into sketchup without having to redraw might solve this). Not only does this occur on the terrain surface, but on regular surfaces as well.

However, I need a new workflow for this. The first issue was tolerable, but combined, these pose a major time issue for this current project. In fact, the cad itself is not complex nor large, it just incorporates a generous amount of curved sidewalks. So I want to know: how do you provide the site in your model?

Am I really forced to use the blurry google earth texture as the ground for my models? Is it preferable just to redraw all sidewalks, curbs, and roads even though I have cad already drawn of this? Certainly this can’t be the case.

Please let me know if more context needs to be provided.
(1) This example is of a curb off of a house on the site plan that was draped on a flat terrain surface. Even though these lines intersect, they refuse to form a closed shape on the surface without being redrawn at multiple intersections, even though they were confirmed intersecting in the cad.

After fixing:

(2) Lines are not being draped from the imported cad.

[RTCool]

I’m not entirely sure what to say. Imported DWG files sometimes become trouble without a clear reason why.

• Is your terrain strictly from geolocation or do have contours from a surveyor’s survey?
• Have you tried Placemaker at all?

One diagnosis tool is to turn off textures, and turn on Show Hidden Geometry. You can see the complexity created by the intersection of your draped geometry and the hidden geometry of the land form.

[suace]

Thanks for the response! I think I can address both of your questions: I apologize for being nebulous about what I refer to as “terrain”. What you see in the images posted is of the flat, geolocated surface. Smart idea about hidden geometry, but this issue still occurs with typical flat surfaces (1). Therefore, I think the same issue would prevalent with topography from contours and imported GE imagery from placemaker.

My sole goal is so not redraw the entirety of the site and just use the true linework already given by civil. For a model with multiple buildings on a developed civil site plan, what is your workflow when modeling the site regarding sidewalks, curbs, and details?

(1) This issue occurs with all types of surfaces:

[mihai.s]

Have you tried Drape, but in pieces, not for the entire model?
Did you import the model at the correct scale?
Have you also tried extruding the edges, and then Intersect Faces, instead of Drape?

@suace

What you see in the images posted is of the flat, geolocated surface.

And if it’s just a flat surface, what are you trying to use Drape for?

[RTCool]

@suace

My sole goal is so not redraw the entirety of the site and just use the true linework already given by civil. For a model with multiple buildings on a developed civil site plan, what is your workflow when modeling the site regarding sidewalks, curbs, and details?

Oh, for the sake of just outputing a an orthographic plan view with the engineer’s linework included, I float the whole drawing above the model like a layer.

Orthographic plan view:

What it really looks like:

[suace]

@mihai.s

And if it’s just a flat surface, what are you trying to use Drape for?

Masterful point. I think this solved the issue with getting this on to a surface, but I feel as though this may come up if I drape with the same linework in the future. Your method of just showing the site on the model may work for for a first deliverable, but I will be developing final renders eventually.

Therefore, any solution as to why this won’t form a closed surface? Using an endpoint extension, all points are closed (shown in red circles)! I may need to create a new topic to address this. Is this an autocad based issue? Why is the interior line cutting, but not the outside line?

[paddyclown]

Hi, what units are you using ?
Often times it’s worth scaling up 100 or even 1000x so as to avoid creating minuscule curve segments that frustratingly don’t join up.
And welding curves before draping often helps.
One thing that often messes things up is draping a dwg that is bigger in area than the “site, or terrain” object.
I wish this whole process were less painful too !

[suace]

See the above replies regarding the drape. If the linework is already flattened, then copying to a flat surface is the equivalent of draping for my needs.

This being said, you are correct: scaling to a larger size usually improves on these issues, but does not solve them. I am convinced the drape tool is either bugged or straight up broken, as I have even gone through the effort of simplifying all “curved” lines to a fraction of the vertices that they were before and it still cannot get it right (there aren’t any minuscule line segments). It is as if the lines themselves are corrupted. Hunting down the hundreds of gaps between lines is not valuable to my client.

This is a major failure in sketchup for me at the moment and I am extremely disappointed.

[paddyclown]

Indeed.
You might like to try Tig’s plugin “superDrape” - SketchUp Plugins | PluginStore | SketchUcation
It may perform better; honestly I can’t remember, as I haven’t had to do this kind of thing for a while (thankfully) !

[suace]

Thanks for this. I will close out this topic for now, as the linework is now draping accurately.

However, I will be creating a new one in reference to this issue that I am still having. Closed lines are not forming/cutting surfaces.

Frustration from CAD site plan to sketchup workflow

Masterful point. I think this solved the issue with getting this on to a surface, but I feel as though this may come up if I drape with the same linework in the future. Your method of just showing the site on the model may work for for a first deliverable, but I will be developing final renders eventually. Therefore, any solution as to why this won’t form a closed surface? Using an endpoint extension, all points are closed (shown in red circles)! I may need to create a new topic to address thi…

Therefore, once this is solved, I will reopen this topic if I have further issues with draping. For example, I noticed that the parent surface was exploded after the tool was run, which would be catastrophic for a surface that isn’t flat like terrain.