Why is default terrain not flat?

[Milos.V]

Really need this one figured out. I need to make terrain flat but default without any elevation data is still showing random, height changes.

Why? how do I just make a flat terrain that I can stick my roads onto. I need exported terrain geometry to be flat.

[Karsten.Saenger]

Hi @Milos.V

how did you create the terrain in InfraWorks?

My suggestion is to create a flat terrain in Civil 3D for your area of interest and import it into InfraWorks via the IMX format.

(Basically, InfraWorks is not made to "create" base data, but to use existing base data such as terrain.)

Alternatively, use the Model Builder to create your base model and the "Land Area" tool to patch a flat terrain on the existing Model Builder surface (SRTM data).

before

after

Note:

A Land Area is draped on the terrain and will cover contour lines and imagery. You can set it transparent to see the images, but contour will not be visible still.

Regards,

Karsten.

[Milos.V]

Hi,

Terrain was not created at all, just aerial image was imported. this is default terrain I assumed would be flat.

In another post I used land area to flatten the elevated area but it still doesn't provide a flat solution. if reduces land to be within 300mm but its not flat.

To obtain Civil 3D just so I can create a flat area seems a vit unreasonable but I'll try the trial version maybe.

[Karsten.Saenger]

Hi @Milos.V

if you only import an aerial image into an empty InfraWorks model it will be draped on a "dummy" terrain that is flat.

There will be no terrain object created. So, if you have terrain there must be other data imported as well.

Please not that InfraWorks expects to have terrain data as base data for all models. It's like in the real world, you need a terrain (earth) to put something on it.

Regards,

Karsten.

[Milos.V]

We have created custom height map created from satelitte data and made sure terrain is just pure white (in black & white elevation map) and water as black with gradient between to act as gentle sloping of land mass into water.

Infraworks still shows is as bumpy terrain. this is using an elevation map. I don't think your description is the issue. I think Infraworks adds bumps to elevation data for no reason. in this case making the export unusable.

[Karsten.Saenger]

Hi @Milos.V

after looking at your initial screenshot again, it looks like the "additional" contour lines are along the tile borders that InfraWorks creates for pre-rendering.

I hav never noticed an elevation change along the borders for a flat terrain.

Is it possible to send the sample data you have created, so that I can take a look as well?

Regards,
Karsten.