Projecting a curved surface onto a flat plane

Using Sketchup Make 2015

How do you project a curved surface onto a flat plane? I essentially want to create an elevation of the front of a train so I can draw the windows that will be draped back onto it but I first need a flat interpretation of the front curved surface.

Can you post an image of the kind of view you are trying to create in SketchUp? That will make it easier to help you.

Trying to project a flat interpretation of the curved front onto the rectangle in front of it (get the elevation). Once I’ve done that I’m going to offset and edit the resulting shape to form the window which I will then use the drape tool to project back onto the curve.

The drape or stamp tools don’t seem to work in reverse however.

Drape and Stamp might work if you rotate your model so that the direction of the operation is downwards along the blue (z) axis.

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Didn’t work :frowning: - thanks though

I’d use the Projections extension to project the edges onto the flat surface. You can get the current version here: SketchUp Plugins | PluginStore | SketchUcation

Instead of using Drape to project the offset back to the curved surface, I would Use Push/Pull and Intersect Faces. Or I would use the Offset tool from Tools on Surface and not bother with the projection at all.


I’m quite certain Anssi’s suggested method does work.

Share the model and we’ll demonstrate.

What is the scale of your model? If your train is not to full scale problems might arise if very short line segments are involved (<1 mm).!1203&authkey=!AOhWNrDufBiRf9Y&ithint=file%2Cskp

It is to full scale.

The model is in the link above. Apologies for the delay. Just upgraded to windows 10 and had a few issues with the internet. Thanks for the help in advance. J

As Anssi suggested…
Drape works when the model is rotated such that the direction of the Drape operation is downwards.

Albeit, it took a 3GHz CPU some time to complete and the result was neither pretty nor complete.
That is, the Drape operation did not result in a closed loop of edges; there were a number of tiny gaps.
The nose of the train is jagged and asymmetric. That’s reflected in the draped edges on the plane below.

The gaps came from the tiny edges in the model.
The tiny edges are the result of when endpoints in one curved surface don’t quite coincide with the endpoints in the adjacent curved surface.