Sites

[Sawyer]

I have had a problem with a project.

This is a large house cut into a hill with a driveway cut into the hill. What civil sent me was really weird, using the topo command created a lot of ugly hills where the cuts into the site just created horrible triangles and lines.

 

I was told the civil went their own way on a few things, didn't get it right and I needed to fake it anyway. I basically approximated the lines and booleaned out what I was a cut (power booleans).

 

SO I was able to fake it but it was goofy and I have 3 more to da (they are not designed yet so I have time). What am I missing? What happened to make the terrain command fail like that? I have never done a site heavy job before how do you do it?

 

Thanks

[siliconbauhaus]

Welcome to the crappy world of making terrains mate

 

I did see a post somewhere that a guy mentioned about using plines for your levels and using lots of segments for each. Then when you go into max use the normalise modifier to make sure the segements are the same number. Then go ahead with the terrain command.

 

From a personal point of view I generally tend to refer to the civils dwg but make my level lines more suitable for 3d purposes.

[Chad Warner]

Yeah-Terrains pretty much suck.

I know for retaining walls and that sort of stuff, the contour lines that I get from civil engineers just stack the lines on topof each other (which is what they should do), but the terrain command can't handle the lines like that. I normally will go back in and refine all the topo, then use the shapemerge command to do my cuts.

[Tommy L]

Im about to do a project just like the one you described (a few semi-subterranean eco-houses in the side of a hill in the Dales, could you keep us posted on your progress? I was going to raise the contours from the site survey and use the terrain command then boolean out the cutaways for the buildings.

However, Im beginning to think i might be better to close the contours and use them to control a loft? I think i will keep more control with a loft.

By the way, 'Glue' tool can be very helpful for contoured sites. ( dropping on foliage/fences/roads etc)

Anyhow, it would be good to share knowledge on this one if at all possible.

Many thanks,

Tom.

[Sawyer]

So here we go. This is a screen grab and a rendered terrain. This is how the civil sent it. I came up with a different solution but it is no where near exact enough. Please also note that civil placed their elevation text in model space and trimed the topos around the text.

 

Also the designer wants me to "be able to change everything if he doesn't like it". Meaning he wants to be able to move retaining walls, driveway etc.

 

Side note I tried this in Revit but all that was exported to me was a 2d plane. Has anyone gotten that to work?

[Tommy L]

Could you post the .max file? or email all you've got to me at thomas@3dcom.co.uk

cheers.

[bjornkn]

Or maybe post the dwg file?

Fom the screen grab it looks like it should be quite easy to make a smooth terrain from it in SketchUp, which doesn't read max files...

[Sawyer]

The files I have are larger than 100kb which I thought was the largest we could post. Anyway anyone who wants can go to

 

 

http://sfrendering.com/index-login.html

 

password is site.

 

Should be able to DL the dwg/max files. Cad file is 2004. I will only have these files up for about 1 week so keep that in mind when you are reading this.

 

Thanks in advance to anyone who tries their hand at this.

 

 

Please note however that these files were just recreated/modified today for this. I have not been working on this site for a while now so I tried to go back to what I had to begin with. Anyway let me know if you have questions. Thanks

[Andrew Schroeder]

I work in both worlds, and what you're after isn't the contour lines so much as the original DTM of the site. All civil surfaces contain a TIN (Triangulated Irregular Network) comprised of the orginal survey points, and the proposed grading lines. The contours are only an interpretation of the DTM. I would recommend asking your civil guys for the TIN. From there you won't (shouldn't) have excessive triangles, and should have a much easier time with the modelling. Of course, you could always ask them for the 3D faces.

[Brian Cassil]

Can you import a TIN or DTM into max?

[bjornkn]

It's definitely different from the topo files I usually get, but this is how it looks after spending about 30 mins on it in SketchUp.

it's certainly not a click-a-button-to finish topo, but with a combination of using automatic skinning and hand editing while snapping at points and edges of the contour lines IMO SketchUp is quite a useful tool for the job.

[Sawyer]

bjornkn:

 

That looks pretty good. Looks like the open places are where the retaining walls would go.

 

Andrew:

 

Yes I was given triangulated faces and I didn't know what to do with them. They looked horrible rendered, and there were so many of them I didn't know what to do with them. I talked to some one about them and they thought that the faces were just for "civil stuff that didn't pertain". I can find those again if anyone wants I can upload this: (maybe I should have uploaded the civil file as it came to me not as I corrected it doh!)

[Andrew Schroeder]

Yes you can. When the civil guys create the surface, they can choose an option (in the Terrain menu) to "Import 3D lines" to the CAD file. When they do that, it'll import the TIN as lines. These could then be used to build the surface in VIZ.

 

Also, I'm not sure if your versions support it, but consider using LandXML to move surfaces between LDD/Civil3D to VIZ/MAX. I've used this on medium sized meshes with good results.

 

-Edit to Add-

Well, the contours you have are derived by linear interpolation through the DTM triangle edges, so essentially the TIN contains the same information as the contours. Of course, the civil field isn't interested in the smoothing, etc. that we're after, so you will have to do some smoothing of the built surface in order to take the edges off. Off the top of my head maybe tesselate and then smooth. There are new algorithm in the latest version of Civil3D for Krigging interpolation, which will yield smoothed surfaces, but I don't see it taking hold in the Land Development arena, maybe more in the mapping field.

[Chad Warner]

I think there's a plugin for it somewhere.

[bjornkn]

I have no ide how to make terrains in Max, but AFAIk there are basically two types of smoothed terrains, just like with images - vectors and bitmaps.

The terrain model is often called DTM (digital terrain model).

TIN is the triangulated irregular network you get when filling the area between contour lines (elevation lines?) with triangles.

The "bitmap" terrain is made from DEM (digital evelvation model) or similar, which is a grid of elevations - every x,y (or longitude, latitude) have its own elevation value instead of a color.

Just like with bitmap vs vector images you need a lot of small squares (pixels) to get a lot of detail in the image/topo, while with the TIN/vector version it all depends on the details in the terrain. If there is a big flat area, like a lake, there's no need to fill it up with hundreds or thousands of small grid squares. A TIN would contain a few big triangles and lots of smaller triangles around the shoreline where the details are changing faster.

One problem with your terrain model is that it contains only contour lines. The ones I usually get from the Norwegian mapping authorities contains a lot of other lines, like break lines, roads drawn with their edges (instead of being described only by the contour lines) etc, which makes it a lot easier.

The problem with the "topo" command in SketchUp, and apparently also in Max, is that they probably use a straight Delauney triangulation method. This is AFAIK basically a 2D technique which looks at the model from the top and tries to create a network by connecting each point with the nearest 2 points to build a mesh with no overlapping lines. As this doesn't pay attention to the z value of each point it often ends up with jagged topos.

That's why I love the flexibility of SketchUp. It allows you to easily select the lines you want to "skin". In such a terrain it means to skip a lot of the contour lines because most of them carry no information. There's no need to have thousands of small triangles when they all are more or less coplanar, and when a few large triangles would do just the same job. Then you could easily add your own break lines and road edges and have SU skin them. Then you could skin the are between those meshes, and finally do some cleanup by adding or moving points and edges which turned out wrong.

This way you get the details where you need/want them, and can leave less important areas of the topo less detailed.

The quick test I did above contained about 3000 faces, and it was by no means optimized.

I spent quite a lot of time trying to find an affordable program that could make terrains automatically from contour lines. The only one I found was SimuTerra from http://compuneering.com/ , which does a pretty good job.

[Sawyer]

bjornkn

 

That was a good bit of info thanks.

 

I remember what the problem was with the triangles now. They would not subdivide. I couldn't tesselate or mesh smooth or anything with them which I thought was weird.

 

But... I was just trying to recreate these files and I got the cad unknown plugin/proxy warning. I got the same warning in max & listening to everyone I am thinking the problem is I have an invalid mesh or a proxy & I can't play with it.

[bjornkn]

I'm no Max user, but if a mesh won't react to such commands in LW I would use the MergePoints command. Sounds like each triangle uses its own set of vertices without sharing with their neighbours - which in LW is fixed with the merge command. I don't know the name of the equivalent command in Max..

[Sawyer]

bjornkn - you got me there! It is because every triangle is a seperate element and they were not merging together that this was looking so weird. So I just welded all of the vertices within a very small thershold and it work. Now I have 1 elemet & 1 object and I can smooth or tesselate or whatever.

 

Cool Beans!

[bjornkn]

So how does it look now?

Could you post an image?

[Sawyer]

Ok I think I spoke too soon. What I now have is a usable mesh object I still have horrible triangulation. Here is a screengrab and a rendering of the site once I add a meshsmooth or tesselate or smooth everything gets funky.

 

Image 1 is the regular rendering no tesselation.

Image 2 tesselation of selected terrain and meshsmooth

Image 3 screen grab.

[Sawyer]

I think I have it or I have something that could be used and modified for individual views. It is not as nice a site as I was hoping for and because of the scope I was really hoping to avoid subobject modifications to individual edges or faces or whatever but I guess if I have a mesh that requires it I need to do it.

 

 

Thanks to everyone who took time with this. If anyone wants a copy of the final mesh as I "fixed" it let me know. Or if anyone wants me to keep the site files at my ftp site let me know, otherwise I will take them down soon.