topic Re: Flood Simulation in ArcGIS CityEngine Questions

Flood Simulation

ziadfilfili — Tue, 08 Jan 2013 08:41:01 GMT

Hello,

I saw on Facebook this video.
I was wondering if City Engine can do flood simulation as found under the link below?
Or Was that real flow ?

http://www.youtube.com/watch?v=JcGXGTiV0Zw

Regards,

Re: Flood Simulation

MatthiasBuehler1 — Wed, 09 Jan 2013 15:59:42 GMT

Hi !

This was done with RealFlow.

CityEngine is 'just' a procedural modeling application, so it has no 'flooding' or other animation features.

I've been playing a lot with RealFlow in past and have been thinking of creating a similar thing, but there are some limitations in RF to create something really convincing on such a scale.

Need flood sims for work or would it be rather a hobby project ?

Re: Flood Simulation

ziadfilfili — Thu, 17 Jan 2013 06:42:48 GMT

Hi,

This is what I thought.

Would be glad if you can assist me with some flood sims.
Any tutorials ?

Regards,

Re: Flood Simulation

MatthiasBuehler1 — Thu, 17 Jan 2013 15:02:33 GMT

Hi !

It's an interesting topic.

The main thing I need to know is :

Is it rather a VFX project, where you:
- work with CFD (computational fluid dynamics) techniques with 'particle based' / 'grid based' techonolies ( using RealFlow, PhoenixFD, Naiad, [FlowLine] or an other software )

or if it's more an engineering project, where you're :
- basically just interested in the scientific 'end result'.

Based on this, the approaches may be entirely different.

Lemme know. 🙂

Matt

Re: Flood Simulation

ziadfilfili — Fri, 18 Jan 2013 05:41:59 GMT

Hi,

Its more for an Engineering project and want to show flood sims scientific result and how would they act towards buildings, streets, and valley nearby as well.

Btw can't I use a mix of both, the scientific result and vfx together ?
I can make some visual effects in a later on phase using Autodesk Maya and some after effects techniques.

Thanks,

The main thing I need to know is :

Is it rather a VFX project, where you:
- work with CFD (computational fluid dynamics) techniques with 'particle based' / 'grid based' techonolies ( using RealFlow, PhoenixFD, Naiad, [FlowLine] or an other software )

or if it's more an engineering project, where you're :
- basically just interested in the scientific 'end result'.

Based on this, the approaches may be entirely different.

Lemme know.

Re: Flood Simulation

MatthiasBuehler1 — Fri, 18 Jan 2013 13:25:00 GMT

Hi !

Something like this ?
https://www.youtube.com/watch?v=W_wJ8vYtMmU
🙂

If you want scientific precision, I'd use the ArcGIS tools which were built specifically for this task that calculate those things with raster files ( using an image based process ) to calculate the height of the resulting flood water above terrain at each point in the city.

You could use that image and create a new terrain layer in CityEngine and use this as base for an animated water shader *. It seems the above user did something very similar in that video above.

*) using something like 0:45 here : http://vimeo.com/55865390#at=0

If you want to go without image-based process but rather particle based, I guess you would lose some scientific rationality because the way how these simulations are run are always a little unpredictable and only hardly properly measurable (m3, flood level) because the only real output usually is a polygonal mesh which can only hardly be converted to a comprehensible hazard-zone map.

So the rendering / visualization of the flood is 1 task - the display of the raw statistical data (maps & metrics) is an other.

Cheers !

M.

Re: Flood Simulation

ZorkoSostaric — Sun, 20 Jan 2013 23:17:39 GMT

That video got me intrigued too so I have tried RealFlow and local data exported from CityEngine. Results look good but for better simulation (not focused on VFX) that accounts building's structural "resistance" a XFlow from the same company was recommended. I haven't tried it yet as I hoping to get an evaluation version.

In any case simulation is going to take a while...

Re: Flood Simulation

MatthiasBuehler1 — Mon, 21 Jan 2013 18:33:21 GMT

Hi Zorko !

Cool you're interested in this too !

I have not tried xFlow yet, I just have some experience with RealFlow.

Have some doubts that xFlow will perform well on the scale of a city.. But if you try it, let us know how it goes !

Matt