Layered Terrain from Contour lines

[peprgb]

Hi,

 

I am trying to get a good-looking layered terrain created with the Compound objects > Terrain option, the contour lines are imported from AutoCAD. I am getting jagged results and although i use Norm Spline (setted to 1 or 2) or Interpolate x2 (or x4) options i get this bad result. I had followed the steps from the two books from 3dats and in this case the closed polylines didn¡'t help.

 

I have some ideas to better this result, converting the polylines to splines in AutoCAD is one (maybe either with "fit" too). In Brian's second book he had arc-polylines and this is cool stuff but i cant get this directly without another app (as far as i know), another one consist on moving the polylines cause if they are so close one from another jagg occurs yes or yes.

 

I would appreciate some ideas of differents workflows....

 

Regards,

[Stephen Thomas]

Why not just extrude each spline individually instead of bothering with the terrain tool? You may need to add a little to the linework in order to make each layer a closed spline but it'll give you a much cleaner result.

[Brian Smith]

Jose,

Sorry, but the limited information you have provided makes it impossible to diagnose the problem. You will need to describe step by step what you're doing and screen shots along the way. There are too many things that could go wrong.

 

The tutorials work exactly as described...have seen many people worth through the books while I watch over their shoulders. I just can't help you without more info.

[peprgb]

Yes....this would be the third option, maybe it takes a lot of time, but on the other hand, with the work i am getting editing vertices, tests converting to splines, 2d pol, fit.... and terrain tool tests..... it seems a good idea

 

Your option is better either viewing the middle part of terrain (in blue) that is very very vertical and i suppose this would be practically impossible with Terrain tool [The first's post image is the part of the left (in green).

 

Thank you very much,

 

Regards,

 

p.d.: sorry my bad/poor english!!

[peprgb]

Ok my fault, these are the steps:

 

1_ Contour lines in AutoCAD each 1meter, simply polylines [image.1]

 

2_ Converted to Splines for smoother results. [image.2]

-Now called "2d polyline"

-More vertices

-The shapes are moved > less accurate (but half-fixed later with "Norm Spl" [image.2.1]

 

 

3_ Imported like "autocad drawing" in 3ds max (tested with "legacy.." with worse results) [image.3]

 

4_ Select all and Norm. Spline modifier setted to 2

 

5_ Terrain tool from Compond Objects > Layered

 

6_ (Trying interpolate x2 or x4 the result is a bit better but heavier)

 

Thanks Brian

Edited February 17, 2010 by peprgb

[Peter M. Gruhn]

OK, I tried a little test and I got something that looks similar.

 

All sorts of problems actually. Quite the mess.

 

It looks like some sort of vertex proximity thing is going on. Scale one contour and it's connection to the layer below will pop in and out of "sawtooth" at various locations. "Oh, that spot belongs on this contour, no that, no this..."

 

Graded solid looks better until you notice that some of the polygons are connecting to the level above - consistent with the errors in the layered solid.

 

I scaled the spline operand up a few thousand because my initial drawing was small. Did not change anything (eliminating the idea that it's a snap distance thing).

 

Switching from No to *2 make all the glitches go away on the simple linear terrain.

 

Graded surface does some optimizations. Allows some turned edges, running some faces up the slope across contour limits. Surface still looks fine. These changes are kept when switching to Layered Solid. They should not be. Retrianglulate helps but does not cure. Seems to be a response to vertical slope.

 

If so, then... nope. Tried scaling verts in source A WHOLE LOT only in x and y to make it more flat. The vertical areas, while flat like Houston were still recognized as vertical. So bad that even *4 is not solving.

 

Attached a cap of the near vert surface (no overlaps) showing how it looks as a graded surface.

 

The short answer is "Hey, Max, don't connect verts across non-adjacent contours".

 

I can "solve" the problem by insterting lots of extra verts in the troubled spots using Refine. That feels like the "wrong" answer.

 

Here's something. Look at this nice bunch of teeth. See how the spline verts are all slopeylike? OK, now watch what happens when I line them up.

 

Ah, but that's not going to work so well on the simple sample. There ARE no verts to line up.

[peprgb]

Thanks Peter, finally i made this part (the green one) with the Stef suggestion, is more time no doubts, but the result rocks, before i was managing at least 400.000 faces terrain (interpolating x2: 800.000, with polys converted to splines in autocad around 800.000 too), now i have around 40.000 and the viewport is flying

 

Is harder but i will finish the rest of the terrain with this simple method (someone said something like "the simplest answer is normally the good one" )

 

Now i only have an issue with smoothing the result, the "smooth" seems to work only with indidivual layers, attaching all or selecting all an applying didn't work...

 

Regards

 

p.d.: a bit off topic: loving the Civil 3D contour lines interpolation options (i knew about it yesterday...)

Edited February 18, 2010 by peprgb
Adden info