Topography and building heights

ENVI-met Monde World Editor (BETA)
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marmuebn3
Posts: 19
Joined: Fri Oct 23, 2020 5:16 pm

Topography and building heights

Post by marmuebn3 »

Hello at all,

first: happy and healthy new year!

My question - may be, its about misunderstanding some features: I created a complex city (only DEM and buildings yet) in MONDE in order to simulate some cutouts in different simulations.
To start, I exported a subaerea from MONDE to SPACES (2.5D), in order to add some plants. To my surprise I found all my buildings as standing on z=0 so that they are more or less covered by the topography. For example, a building of 15m height, placed on an area where the DEM provides an elevation of 12m, the building height is 3m (obove ground level). I expected the building-top to at 15m + 12m = 27m.

Building heights have been imported from OSM. At that time there was no knowledge about DEM ground levels. Grids in z-direction are fine enoughis fine enough to represent the typical building heights.

How can I correct MONDEs behavior to get the results that I expected. Do I have to export to 3D?

Tim
Posts: 1989
Joined: Mon May 15, 2017 3:46 pm

Re: Topography and building heights

Post by Tim »

Hi,

Happy New Year to you as well!
When exporting the model area out of Monde, go into More Options and disable "Use leveled Buildings for Buildings in DEM".

Best regards,
Tim

sccandy
Posts: 3
Joined: Fri May 22, 2020 1:39 pm

Re: Topography and building heights

Post by sccandy »

Hi,

I have a similar problem. I imported building heights from a shapefile
and the topography from OpenTopography (because it is not possible to
import own topography, right?). I disabled your mentioned option during
the model export, nevertheless, the buildings 'break' along the topography.
Do you know what the problem might be?

Moreover, I have no idea why the walls of my buildings are ribbed.
Is it because of the grid size? But it would be unrealistic to lower
the grid resolution below 1 m..
Ribs and Topo.PNG
Thanks,

Alexandra

Tim
Posts: 1989
Joined: Mon May 15, 2017 3:46 pm

Re: Topography and building heights

Post by Tim »

Hi Alexandra,

I'd recommend you to run this model without DEM, it makes things much easier and the simulation might be more stable. See here for more information: http://www.envi-hq.com/viewtopic.php?f= ... f33#p11603.

However, if you are really into DEM and still want to use it:
Yes, importing own topography is not possible.
In general, the activated option should avoid that buildings are broken along topography, so you would need to activate it if you want that. However, I don't see any breaks in the buildings in your screenshot?
The buildings are ribbed because you chose a suboptimal model rotation (probably no rotation at all). If you rotate the model area by 45°, buildings are aligned with the model area extension and will not be ribbed anymore.

Best regards,
Tim

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