Creating a landscape from spot levels

Stewy · 18 Dec 2008, 17:44

Hi everyone, I am a new Sketchup user and have gotten myself into a bit of a fix. I am a town planner and building designer in the UK and use Caddie 9.1 as a tool - quite happily. I have been playing with SU as a way of illustrating building designs in 3D and i just love using it. My current project, and my first real SU job, is to draw a couple of existing barns - I have good survey data and have quite happily elevated them. I now need to create the topogtaphical base and drop them in (sounds easy!!!). I have a 2D spot levels DXF plan which imports fine but without the actual levels text. I also have beens sent by the survey company a 3D level plan, which also imports fine and has each point at the right level relative to one another. However, i can't figure out quite how to take those spot levels and create a 'terrain plan' onto which I can insert the buildings. I am sure that Im just being dim and that there is a simple way of doing this.

Any suggestions or help would be gratefully received, the forum looks great by the way, I can see me being in here often,

Stew Rowe

tomsdesk · 18 Dec 2008, 19:39

Welcome, Stew. If I understand you correctly: just connect the dots with triangles.

Chris Fullmer · 18 Dec 2008, 20:18

What is imported? is it actual lines or soemthing? You can create a TIN using the sandbox tools. First go to Preference>Extensions and turn on sandbox tools. You get some more icons and one is "from contours". Select all the lines or dots and then run that script. It will work on non contours too.

There is also a cloud.rb script that makes a terrain from a list xyz points. I have no clue how to use that script because I never get that kind of raw data.

What you want is definiately possible. Play around with the suggestions and post back with any further questions, images, models,for us to check out. Good luck,

Chris

Gaieus · 19 Dec 2008, 07:02

Yes,it all depends on what kind of geometry - linework, guide/construction points, "crosses" or whatever you received. There are tools for everything just let us more precisely know.

Stewy · 19 Dec 2008, 19:24

Hi guys, thanks for the help to date. The imported topo' data is a series of crosses in the horizontal plane and then when I rotate around they are at different heights relative to one another. I did try linking them in a series of triangles and colouring each plane green, which looked great. I was then going to sort of round it all off somehow. However, it occurred to me that depending how I linked the points together I could produce different terrain from the real one - or am I being dim.

I then thought that I could bring the topo crosses over the sandbox and pull up ground to each point and then somehow smooth it all off but Icouldn't work out how to actually do it.

My final thought was "join the Sketchucation forum"!!! and here I am...

As an aside, I am really really pleased with the barns and the product is outstanding and easy to use, I look at the work you do and it is inspiring and makes me want to get better and better.

Any help would be really appreciated,

Thank you for your time,

Stew

Chris Fullmer · 19 Dec 2008, 21:15

for the sand box tools, its like I said before. Select all the crosses and then activate the "from contours" tool. That should do the work for you though you might need to clean up the edges.

Chris

Stewy · 20 Dec 2008, 00:10

Hi,

Ive attached the file that I have so that you can see what Im seeing, can I work with it in SU?

thanks,

Stew

levels base plan.skp

Chris Fullmer · 20 Dec 2008, 01:23

[flash=812,612:2byhrfit]http://chrisfullmer.com/forums/terrain from dots.swf[/flash:2byhrfit]

There you go. Thanks for uploading the file. That genereally solves most problems The problem was that each point was grouped. So the key is to select all and ungroup them. Then run from contours.

Chris

Gaieus · 20 Dec 2008, 08:33

The basic idea would not be bad, Chris, except for the fact that these crosses should represent 1 co-ordinate point each and the way you create the mesh will add significant amount of extra triangles due to the actual geometry of the crosses.

What we should do here is to turn the components (each cross is an instance of the same component fortunately) into guide points and run a nifty plugin called points_cloud_triangulation.rb.

We will actually need three plugins altogether - for the convenience I have zipped all here - due credits can be found inside the ruby files. Unzip the files into the Plugins folder under your SU app (as I see you are running SU 5 but these plugins should work just fine there, too).

The necessary three plugins

So the steps involved after installing the plugins and restarting SU are

Edit any of the "cross" components (double click)
Select all inside and go to the Plugins menu > "Set center point"
(this will set a guide point (construction point in SU 5) inside each cross component)
delete the cross geometry but leave the construction point > exit the editing context of the component.
select all instances of the component > right click > Explode
This will keep all the guide points still selected so now go to the Plugins menu again and select "Triangulate points".
You will be prompted by a question if you wish to put the new mesh onto a specified layer. If you wish,you can answer yes and go on creating a new layer now.
After the triangulation, you end up with your mesh that is

neither grouped
nor softened

so you may want to triple click > right click > group and/or soften.
See file attached.

Grouped, softened

Stewy · 20 Dec 2008, 10:24

Hi Chris and Gaieus,

Outstanding! thanks, Chris, the video is really helpful and has inspired me to get it right. I spent many hours yesterday evening playing with the various plugins and searching the archives for guidance - I didn't get it to work but I have learnt a lot more about SU!.

I understand what you mean Gaieus about the crosses needing to be converted to into guide points and will lead the plugins that i haven't already later today. At the moment my wife has plans for me with the hoover and some more christmas decorations!.

I'll let you know how I get on later today - with SU not the hoover!

Thanks again and a merry christmas to you all,

Stew

Gaieus · 20 Dec 2008, 10:25

@stewy said:

I'll let you know how I get on later today - with SU not the hoover!

Howard leslie · 20 Dec 2008, 11:27

Stewy,
This Tutorial may help also:
http://www.sketchucation.com/forums/scf/viewtopic.php?f=18&t=4276
.......
Regards
Howard L'

Chris Fullmer · 20 Dec 2008, 13:30

Ahh, thats a good point about the extra geometry Gaieus, I didn't look at it with hidden geometry on to notice it, but i'm sure your right.

A solution without the plugins would be to go in to one of those components and just draw a single line straight down from the center. Then delete the cross, leaving just a vertical line. The top of the line must be the old center of the cross.

Then do the same of exploding them and running from contours. It will make the cleaner geometry.

If you really needed to save the original crossees that is workable too. make a copy of all of them and move it straight up on the blue axis 50m or as large as needed (but in your model 50m is perfect). Then right click on them (with all of the new copies selected stiil) and choose "make unique". This will turn all of the selected identical components into a single new component, thereby saving your original x component. Then go edit one of the ones down below as explained before with the straight line. Then explode the lower lines, and run from contours on them. You get the terrain and still have all your crosses floting above in the air. Then go select all the crosses and move them down to the terrain - precisely 50m.

Anyhow, slightly more complex to do it this way - with editing the X component, but Gaieus is definitely right that the other way created too much geometry. But this way you dont need any extra plugins. (Not that plugins are bad, they are quite great really. Just sometimes its good to know how to do stuff without them.) Anyhow, good luck!

Chris

Anssi · 20 Dec 2008, 13:53

I once posted to the forum an Autolisp file that did something similar in Autocad to spot heights that were simple text objects (common in survey files here), but I didn't realize that a vertical line would be much better than a horizontal one. I must try to correct that. Thanks Gaieus for pointing that out.

Anssi

Gaieus · 20 Dec 2008, 14:19

@anssi said:

Thanks Gaieus for pointing that out.

Anssi

That was actually Chris - and yes, that's an ever easier way I didn't think about. The from contour tool works only with real geometry (thus it cannot handle guide points) BUT by using vertical lines we can fool it since it will only take into consideration the top point of them.

baz · 1 Jan 2009, 04:52

Great thread guys, Ive been trying to get my head around contours from points and the triangulate points plugin and this thread has done it for me.
hope you all have a great year.
baz