Creating a topography 3d solid model

Hi.

I currently have a .dwg with height guidelines.

I want to create a 3d model of the landscape, block like with the topography as surface.

I've tried creating surfaces, one for the bottom (sea level) and then one for each height area. But I can't figure out how to make this a nice block model with a smooth surface.

Maybe I'm doin it wrong to begin with?

Any help is much appreciated.

The final result I'm looking for is one model showing the topography of today, then another model showing how I want it to look. Then make a calcultaion of how much mass I have to remove to make the landscape look like I want.

Welcome to the forum!

What do you mean by "block model"? What do you mean by "height guidelines"? How are you using them to create your surfaces?

With Civil 3D it's easy to get the cut/fill totals between two surfaces. The catch is that you have to build the two surfaces.

By block model I mean I want a solid "piece of earth", as if i cut a square of the landscape and made it to a model. A cube, with the topography on the top side.

By height guidelines I mean that I have lines showing the height in different areas, but no surface to begin with.

I'll add two printscreens to show you what I mean:

Model 1

Model 2

The black border is the bounday, there I want the "walls" of my block to be. The light blue lines is the "height guidelines" I'm mentioning" and the wite lines I added to show how I want it. The thing is that it's now just a wireframe, hollow and with no surfaces. As you can see the blue lines are in the right height, the black borders are at sea level where I want the bottom of my block to be.

I just want to make this into a solid block, with the top surface showing the difference in height (smooth landscape like).

Hope you understand what I mean and thanks alot for you help!

I don't understand why you need these "blocks." If the goal is to find the amount of earth you need to add/remove in an area to get a desired result, you would typically use surfaces.

In AutoCAD, a surface is really a collection of points, each with a location (X and Y coordinates) and an elevation (Z coordinate), along with a set of triangles connecting them. It's not pretty, but it gets quick results. To find the difference between two surfaces, AutoCAD creates a grid. It averages the elevations of a surface in each square of the grid, which effectively gives it a set of blocks of different heights (that's the sort of "block" I originally thought you meant). Then it does the same thing for the other surface. The area of each block is constant, so it's simply a matter of subtracting the height of one block from another, adding them all together, and finally multiplying by the area.

Naturally you can fine-tune the process by adjusting the grid intervals and the surfaces. If you want something pretty, you can draw 3D faces around the surface and render it. It may be possible to create a 3D solid using a surface on the top side, which would give you what I believe you want.

Thank you so much! Since (as I suppose you allready figured out) I'm doing this for the first time I thought that I needed to create a mass from sea level to surface for the current topography, and one for the one I want. Then measure the mass that I need to remove to get the result.

But if I understand it correctly now I only need the surface for the calculation? So I simply make two TIN surfaces from the elevated polylines I got (one surface for the current, and one for the desired topography) and then Civil 3D can calculate the difference in mass?

I'll defenitly try this. If you have any tips on how to do he calculation it's much appreciated. I'm doing this for a school project where I'm doing calculations on how much it will cost to make a planar surface in the environment to build a large house on. I have a "price" per m3 to remove the mass, all I need is to know how much mass I will have to remove. The goal isn't to make a pretty model, just to get the numbers I need.

Thanks again!

Surfaces Utilities Volumes

surface 1 surface 2 = answer