Terrain from contours - improve on native 'from contours'?

EarthMover · 25 Apr 2012, 23:01

For a SU plugin, it is possible to handle some cases, but it is probably not very convenient. Here is an attempt I started some months ago but that I stopped because to get acceptable performance you would need to offload some pieces of the algorithm to C / C++ (I am lazy to write C extension which have to work in both Windows and Mac and have no experience in this field).

[attachment=0:2l6fep6v]TopoShaper simple.gif[/attachment:2l6fep6v]

Fredo

To bad that never manifested. That's looks incredible Fredo!

fredo6 · 29 Apr 2012, 00:12

@brookefox
I reworked my experimental plugin to adapt to the rectilinear closure of contours.
Here is the result on a rectangular mesh. I had to fix 2 contours which were not perfectly aligned with other in their rectilinear portion.

Contours Brookefox - TopoShaper.skp

It is still slow, and anyway, if I pursue, the methods to improve the generation of terrain will add up calculation time, in particular:

Use triangulation instead of rectangular mesh (more exactly something like constrained Delaunay)
use a more advanced interpolation technique to get smoother transitions

Fredo

PS: I guess that Trimble will soon add this type of functionality as part of Sketchup (or with a bridge to an external program).

EarthMover · 1 May 2012, 22:43

Fredo, I don't think that is slow at all for what it is doing. This tool has been something I've wanted from day one using Sketchup. I beg you to tidy it up and release it. In the meantime, I could beta test it for you.

fredo6 · 1 May 2012, 23:33

@brookefox and EarthMover,

Thanks for the feedback. I'll see if I can release something beta in the coming days.

Fredo

brookefox · 2 May 2012, 01:27

Fredo, I wish I had something more helpful to say than 'looks great', but that maybe is a good thing. Perhaps the other fellows will stop back by, they seem to have much more experience than I have. As far as interest in and good use for such a plugin, I would say most definitely.

@unknownuser said:

Are the topmost contours supposed to be rounded in their inside or just left as a plateau?

To me they are no different from any of the others. Your results to me look fantastic.

You mention the rectilinear closure of the contours, which was done manually by me to make level faces and which I gather is actually unnecessary and even counter-productive.

brookefox · 2 May 2012, 01:29

11 + 7 seconds for the slow and fancy one.

Too simple... Complexify, make inscrutable options so the ignorant can pester you for answers. You know I'll be back.

EarthMover · 25 Jun 2012, 17:22

@unknownuser said:

@brookefox and EarthMover,

Thanks for the feedback. I'll see if I can release something beta in the coming days.

Fredo

Hey Fredo,

Any chance on seeing this beta plugin in the future? Could really use it on a few projects I'm working on. If not, no worries, I know you are busy.

Thanks.

pbacot · 25 Jun 2012, 18:31

@brookefox said:

@unknownuser said:

Are the topmost contours supposed to be rounded in their inside or just left as a plateau?

To me they are no different from any of the others. Your results to me look fantastic.

That's a valid question. I suppose the plugin has to assume and make some sort of rounding-off based on the lower contours. It's easier for the user to flatten after if needed. Alternately user can add a small contour or point to indicate the peak.

This looks great, I was just wanting something like this yesterday. I try other skinning plugins on contours but they don't do so well and for all the trouble I end up back with Sandbox. Wonderful coding!

fredo6 · 26 Jun 2012, 12:36

@pbacot said:

This looks great, I was just wanting something like this yesterday. I try other skinning plugins on contours but they don't do so well and for all the trouble I end up back with Sandbox. Wonderful coding!

Could you post or PM me your model.

The main reason why I don't release it quicker is because I have not worked too much on the validation of input contours and handling of corrections.
And of course, I have not really tested on real-life models (actually only the one posted by brookefox).

Fredo

pbacot · 26 Jun 2012, 14:18

I'd be glad to PM it to you! Will do today. Thanks, Peter

fredo6 · 30 Jun 2012, 21:47

@pbacot,

By the way, I observe that the native 'From Contours' plugin does a rather good job on your example of terrain.

Because TopoShaper uses a more accurate algorithm (to cope with cases of more abrupt changes of relief and also saddles), the analysis of the contours is more tricky and I'll need some time to write a decent code to handle it.

Fredo

PS: and again, I'm pretty sure Trimble will adress the generation of terrain from contour in a next release of Sketchup

pbacot · 30 Jun 2012, 22:17

Yes sir,

That existing terrain is not too problematic for Sandbox, but I assume a more regular clean mesh, as I think you are after, would serve better for subsequent "regrading". Thank you.

It seems the skinning plugins don't work where ridges twist about as in this case, and SB seems to work that out OK.

Peter

Panga · 2 Jul 2012, 09:40

Fredo,

I'll Join Earthmover and others to say that what you tried to do with this plugin attempt is my biggest dream in SU !! As a landscape architect, you can't imagine how much time I spent to clean the terrain mesh because of SU native triangulation prevent using the mesh for may things...so...I'll be very gratefull if you can give us even an alpha version of it !!

pbacot · 8 Jul 2012, 18:02

For ideas on terrain mesh results:
http://www.formz.com/products/bonzai3d/bonzai3dFeatures.php?init=27

fredo6 · 8 Jul 2012, 18:45

@pbacot said:

For ideas on terrain mesh results:
http://www.formz.com/products/bonzai3d/bonzai3dFeatures.php?init=27

Thanks. That's more or less what was my intention.

This is why I need to write some extension in C to have enough speed for the preview mode.

But I am a little bit reluctant to engage in this because I am pretty sure that Trimble will provide a bridge to a Terrain from Contour program in a next release of Sketchup (I guess this is what field engineers need)

I need to think about if I can make a simple beta release quickly. The version I have currently works on close contours only.

Fredo

tald311 · 9 Jul 2012, 02:45

would LOVE this tool. Very needed. amazing as usual Fredo.

pbacot · 25 Nov 2012, 20:38

With Vali Architects new Instant Terrain plugin.

Contours at height. Sandbox "from contours". VA InstantTerrain.

This doesn't really address the OP issue, but it's a way to apply a regular mesh to the terrain. And simplify--if you use a larger spacing.

I know, the contours have parts missing--just the most convenient example to grab at the moment.

Some berms added with Artisan

pbacot · 26 Nov 2012, 10:48

Using Brookefox model, two things:

The contours do not have enough points for Sandbox. I added 2-3 times as many vertices per curve in some of the countour model.
A picture of the Sandbox result and some of the model run through Instant Terrain at fine setting. [EDIT: I ran Instant Terrain for whole model at 75' spacing--last image.]

fredo6 · 25 Dec 2012, 13:38

I resumed some work on Toposhaper, in particular around the identification of contour zone and interpolation.

Here is the current state on Brookefox' model, with various resolutions on a quadrangular mesh
Toposhaper - Test 24 Dec 12.zip

It still takes many seconds

One issue I came across is about zones bordered by a single contour, either loop contour, or open to the outside. In the current version, I try to figure out a kind a simulated relief based on the surrounding elevations.

Fredo

pbacot · 25 Dec 2012, 18:55

This looks fantastic! I would think it should take more than a few seconds. Did you modify the Brookefox contours beforehand?

Happy Holidays, Fredo! Thanks for sharing your gift. Peter