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Re: [WCS] VNS - visualization of forest growth for many stands

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  • Chris 'Xenon' Hanson
    ... Because traditional GIS doesn t really think in the fourth dimension (time), there are no real accepted methods for coding one dataset with multiple
    Message 1 of 3 , Oct 15, 2007
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      Daniel Laubhann wrote:
      > I work with VNS 2.86 (with forestry wizard) and try to
      > animate/visualize forest growth over a period of at least 50 years for
      > many different stands. I have calculated different growth curves for the
      > stands and want to visualize the growth depending on that curves (for
      > schools and decision maker). I tried the visualization for a single
      > stand and only for changing density (later also high and maybe tree
      > composition should change) by setting keyframes at different density
      > values (stems/hectare) for different times (e.g. 0, 10, 20, 30, 40 and
      > 50 years) (aligning timeline to the growth curve). That work well for a
      > single stand, but is very time consuming for many. Is there a
      > possibility to read out densities of a database for different stands and
      > different times simultaneously?

      Because traditional GIS doesn't really "think" in the fourth dimension (time), there
      are no real accepted methods for coding one dataset with multiple time-slices of data
      representation. You could have multiple attributes for each parameter, IE:

      DENS0, DENS10, DENS20, DENS30, DENS40, DENS50 for density at each of the time periods.
      But, the forestry wizard doesn't really know this schema automatically, and can't automate
      the process.

      You could have multiple shapefiles, each with the same polygons but different sets of
      attributes, and use Scenarios to swap them out. This would allow you to easily automate
      production of each time-period, but you can't animate between them. You could only produce
      stills of each time period and make a slideshow where you fade between those stills. I
      think this method is a common workaround for situations where the project doesn't merit
      the amount of labor needed to setup real animation as you did above.

      > The other way I tried, was with the material gradient driver of the
      > ecosystem: I set one material gradient at 0% position and linked it with
      > one database (thematic map) where all stand densities were listed for a
      > given year. A second material gradient I set at 100% linked with a
      > database where all stand densities of a later year were listed. But when
      > I run the animation the densities seems to change correct but trees
      > disappear and appear randomly.

      I believe this is to be expected. There's no internal correlation between the two
      materials, so VNS's normal magic for keeping distribution stab;e during a density increase
      or decrease can't do its job.


      Your questions are very good, and show a serious appreciation of what VNS can do. It's
      just that automating the complex process is not yet practical.

      > Thanks in advance!
      > Daniel
      > Dipl. Ing. Daniel Laubhann
      > University of Natural Resources and
      > Applied Life Sciences
      > Dep. of Forest- and Soil Sciences
      > Inst. of Forest Growth and Yield Research
      > Peter-Jordan-Straße 82
      > 1190 Vienna
      > AUSTRIA
      > Tel.: 0043 1 47654 - 4208 (Tue - Fri)
      > Fax.: 0073 1 47654 - 4242

      --
      Chris 'Xenon' Hanson | Xenon @ 3D Nature | http://www.3DNature.com/
      Virtual Globe: http://virtual-globe.org/
    • Daniel Laubhann
      Thank you Chris for your quick answer! So, I will do it with a slideshow. Good to have a comment on my questions from am VNS-Pro for justifying to our
      Message 2 of 3 , Oct 15, 2007
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        Thank you Chris for your quick answer!

        So, I will do it with a slideshow.
        Good to have a comment on my questions from am "VNS-Pro" for justifying
        to our project partners ;-)!

        Daniel

        >>> Chris 'Xenon' Hanson <xenon@...> 15.10.2007 17:36 >>>
        Daniel Laubhann wrote:
        > I work with VNS 2.86 (with forestry wizard) and try to
        > animate/visualize forest growth over a period of at least 50 years
        for
        > many different stands. I have calculated different growth curves for
        the
        > stands and want to visualize the growth depending on that curves
        (for
        > schools and decision maker). I tried the visualization for a single
        > stand and only for changing density (later also high and maybe tree
        > composition should change) by setting keyframes at different density
        > values (stems/hectare) for different times (e.g. 0, 10, 20, 30, 40
        and
        > 50 years) (aligning timeline to the growth curve). That work well for
        a
        > single stand, but is very time consuming for many. Is there a
        > possibility to read out densities of a database for different stands
        and
        > different times simultaneously?

        Because traditional GIS doesn't really "think" in the fourth
        dimension (time), there
        are no real accepted methods for coding one dataset with multiple
        time-slices of data
        representation. You could have multiple attributes for each parameter,
        IE:

        DENS0, DENS10, DENS20, DENS30, DENS40, DENS50 for density at each of
        the time periods.
        But, the forestry wizard doesn't really know this schema automatically,
        and can't automate
        the process.

        You could have multiple shapefiles, each with the same polygons but
        different sets of
        attributes, and use Scenarios to swap them out. This would allow you to
        easily automate
        production of each time-period, but you can't animate between them. You
        could only produce
        stills of each time period and make a slideshow where you fade between
        those stills. I
        think this method is a common workaround for situations where the
        project doesn't merit
        the amount of labor needed to setup real animation as you did above.

        > The other way I tried, was with the material gradient driver of the
        > ecosystem: I set one material gradient at 0% position and linked it
        with
        > one database (thematic map) where all stand densities were listed for
        a
        > given year. A second material gradient I set at 100% linked with a
        > database where all stand densities of a later year were listed. But
        when
        > I run the animation the densities seems to change correct but trees
        > disappear and appear randomly.

        I believe this is to be expected. There's no internal correlation
        between the two
        materials, so VNS's normal magic for keeping distribution stab;e during
        a density increase
        or decrease can't do its job.


        Your questions are very good, and show a serious appreciation of
        what VNS can do. It's
        just that automating the complex process is not yet practical.

        > Thanks in advance!
        > Daniel
        > Dipl. Ing. Daniel Laubhann
        > University of Natural Resources and
        > Applied Life Sciences
        > Dep. of Forest- and Soil Sciences
        > Inst. of Forest Growth and Yield Research
        > Peter-Jordan-Straße 82
        > 1190 Vienna
        > AUSTRIA
        > Tel.: 0043 1 47654 - 4208 (Tue - Fri)
        > Fax.: 0073 1 47654 - 4242

        --
        Chris 'Xenon' Hanson | Xenon @ 3D Nature |
        http://www.3DNature.com/
        Virtual Globe: http://virtual-globe.org/
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