How to drape a part of the site's terrain only



Hi. I’m wondering how you can drape a particular section of a terrain model. I’ve watched tutorials where part of the site is ‘cut out,’ then the image is draped onto that section of the model. However, I wonder if there is a way to drape an image over a part of the terrain without having to excavate part of the site in Sketchup first. Hope what I’ve written makes sense. Thanks in advance for answers.


Sharing a photo or the *.skp model file would help us better understand your question.



A bit more effort in describing what you’re working with and what you hope to achieve would save us both considerable time and effort.

From what I can tell from your additional (albeit wordless) description, you have an image of a site plan drawing applied to a Face positioned above a terrain model.

Do you want to incorporate the image of the site plan drawing into the existing aerial image of the terrain model?



You’ve already posted that image. How about giving some additional information to help clarify what you want? Don’t make it hard for others to help you.


Something like this?


Apologies for the lack of detail. The inquiry got a bit rushed. I want to incorporate the image of the site plan drawing (2D) into the existing terrain model (3D). So that the 2D images becomes draped over the 3D terrain exactly where the site plan corresponds with the ground.

I’ll try what you’ve suggested Chris Dizon. I’ll reply to tell you how it went. Thanks a lot for the tip.


Hi again.

The method suggested above did not work. I’m not sure what the exact cause is. Is it that the terrain model is different to the one in the example video above?

The terrain is a Group. The site plan massing is a Group. I tried intersect faces with model. That did not work.

Here’s what the terrain looks like:

Not allowed to post image?

When i try to intersect, the Sketchup file freezes:

Not allowed to post image?

I’ve got the sandbox toolbar. Can I use one of those functions to get the job done? My suspicion, as mentioned, is that the issue has to do with the type of terrain - which has mutliple faces/mesh (not sure about the technical terms so please check the screen shots).

Not allowed to post image?

Any suggestions would be much appreciated. Thanks.


Ok, so I got the method to work (Sketchup stopped being frozen). The only issue is that the method is pretty labourious since you have to paint each face within the outline of the site plan massing. I’ve painted a small portion so far:

So I’m still wondering if there is a much simpler way of achieving the same result, using the drape tool or something.


In image that gives an indication of how time-consuming said method would be:


This does not have to be the case. You can paint all of the surfaces at one time. The terrain surface is probably not soften/smoothed correctly. If done right, SU should see the cutout as a single surface to paint.

Can you upload or allow us to download your model so we can take a look?



I’ve uploaded the smaller siter terrain model. I only want to paint onto the Surface within the polyline that is clearly visible ontop of the terrain. I’ve deleted the 3D massing with the site plan as I’m not permitted to share that. Thanks for the help!


Ok, so I don’t seem to be able to upload the Sketchup file. Why is that? I could share the model via the file transfer program Sprend, for example, if you wish to send me your e-mail adress.


I have PM’d you. Either email me or reply to the PM with the model download information



There are a few items that were not correctly set so hopefully, the following points will help you out.

  1. Your Style settings were not correctly set to help you with what you were wanting to do. Your Style only had Profiles active while Edges were turned off. You want the edges ON while you are modeling. This way you can visually see how the modeling procedures are affecting your geometry. Read further as this may become apparent. In your scenario, you want to see the linework while performing interecting.

  1. Now that you can see the triangulation, you will want to smooth/soften the terrain. The need for this is to make SketchUp treat the terrain as a single surface and not a bunch of triangles. This is critical!

–> Open the Soften/smooth dialog (Window > Soften Edges )
–> Select the triangulation you want to soften/smooth.
–> Once selected turn on both Smooth Normals & Soften Coplanar … use the slider bar to make the terrain smooth. It should take a lot.

Now that you have soften/smoothed the terrain, SU will treat the terrain as a single surface. You can see this by using the select tool and if you perform a single click on the terrain, the entire surface should be selected. NOTE: The terrain is still made from triangles but it visually displayed to you as a single surface. You can see the triangle if you turn on Hidden Geometry.

  1. Intersecting. – It looks as though you did not perform the Intersect in the correct context.
    By using the intersect feature, you are wanting to cut into the terrain to issolate a particular section of the terrain that will use your new texture. The intersecting line work you produced was create outside the terrain group and not IN the terrain group.

When you have the cutting shell positioned, you should enter into the context of the smoothed terrain group. Once inside, select the terrain surface and use Intersect Faces – With Model. This will create the nessessary linework to break the surface.

Here is the finished intersect. Note that the surface is now broken into two surfaces.

02 PM

  1. Texturing the isolated surface

With the new texture image positioned above the isolated surface you are almost ready to apply the texture.
First - be sure the texture is a PROJECTED texture. To check, right click on the texture and select TEXTURE > PROJECTED

18 PM


Go back into your terrain context … Sample the image texture … and apply to the isolated surface.


Now you can use the soften smooth again to re-establish a single surface or reset your STYLES for presentation purposes.

I hope this helps. Be sure to go to YOUTUBE for more information on how to work with terrain and textures.



Hello Chris.

Thanks so much for the advice.

I have tried to follow the steps for the full model. The terrain in this (other) Sketchup file is a component. When I choose to edit the component, the entity info does not show options to smooth/soften edges. Do I need to explode the component first? Unsure what I should do. Appreciate the help.


Med vänliga hälsningar

Carl Stjernström


could you try uploading the image again? It didnt come through.

The Soften/Smooth option is not in the entity info area. It is its own dialog launched from either the window area or from selecting the geometry and then context-click (right-click) on the selection.



Hello Chris.

I right-clicked on one of the lines (see attached image), then the entity info became visible on the right side of the screen.

I understand that I then need to tick the boxes ‘Soften’ and ‘Smooth.’ However, I have only selected one line. How do I select all lines to get the desired effect for the entire model? You seemed to have been able to achieve such a result in your previous example, so I don’t know what piece of information I’m missing.

The terrain is within a component. I don’t seem to be able to explode the component without Sketchup crashing.

Please let me know if you would like any further information.




To select all… Edit > Select all (Windows CTRL-A) (Mac Command-A) or you and do a triple click … or you can do a window sweep selection

Here is a video pertaining to the SketchUp Select tool

Do not use the entity info soften option. Use the Window > Soften dialog. This will give you more manipulation options



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