By David Crowther
In a recent training course I was asked if it was possible to update the Terrain in the model created by the Model Builder? For example if a Topo Survey was taken, could this be added into the Model to improve the accuracy of the terrain surface?
In the model below of Shrewsbury UK (created using the in-built InfraWorks model builder) I have removed all other layers apart from the elevation/terrain that the InfraWorks model builder uses. The remaining terrain layer was generated using information from Bing and can be up to 100metres between survey point, making the data a little inaccurate for detailed site work.
Using the DATA SOURCES pane and the ADD > RASTER option you can browse to find more accurate terrain files – for example I have a number of topo survey terrain files for Shrewsbury which have been supplied in ASCI format.
Once opened, the more accurate terrain files are grouped together and are added as one layer in the DATA SOURCES panel. You will then need to configure it by double clicking on the layer and in the Geo Location Tab choose the Coordinate System to use – e.g. BNG.
The updated Terrain Layer (Shrewsbury_Terrain) is then added into the Model, but you may not be able to see it!
Next, from the Create & Manage Model toolset use the Surface Layers tool and you can see that it has added the new terrain under the UN-CATEGORISED folder.
If you now drag the new Terrain layer down the list and into the GROUND SURFACE folder and then switch the layer on using the YELLOW light, you should now see that the Model auto updates to show the new terrain/elevation… which is a more accurate terrain surface.
If you only have one new file for your Topo Survey which could be in the centre of the main site, again repeat the steps above, but this time only open the single tile.
Once configured and moved into the Ground Surface folder in the SURFACE Layers list – you can see that the one (more accurate) tile has been stitched into the model. See below where the terrain has been updated to the left of the Surface Layers tool.
So, if you have a more accurate Topo Survey file, you can do the same to add that to your existing/original InfraWorks model to make the terrain/surface more accurate for your detailed site work.