| GIS: Georendering for Forestry Applications
Georendering takes GIS on step further to better communicate sustainability
studies for a lumber company in California.
By Laura Lang Sustainability is today's hot button for describing long-term planning methods that encompass goals of both for-profit corporations and conservationists. Worldwide initiatives asking for scientific demonstrations of sustainability as a funding requirement ensure hundreds of millions of dollars will be spent training staff and developing datasets and methods for producing sustainability plans.
For forestry companies, sustainability means accurately predicting harvest levels and balancing them with forest productivity for decades or even centuries to come. Such deliberate resource conservation ensures a long-term profit base and eases worries of environmental groups concerned about ecosystem depletion.
GIS provides a data warehouse and toolset for sustainability studies, contributing information on tree types, locations, age and health that can be combined into color-coded analysis maps and understood by corporate decision makers and members of the public. Until recently, though, the maps were too static and difficult to interpret for effectively educating or convincing nontechnical viewers.
Enter VESTRA Resources of Redding, Calif., a 20+ person GIS consulting firm making a name for itself these days with innovative analysis and visualization projects. "For some time, we've been applying GIS to help forestry, agriculture and other clients define their responsibilities as land owners and protect public-trust resources," says VESTRA President Art Stackhouse. "Now, we're going one step further with georendering." A New Look-See
VESTRA recently pioneered the idea of georendering, using GIS in combination with a photo-realistic rendering package, to better communicate sustainability studies for The Pacific Lumber Company (Scotia, Calif.).
Pacific Lumber owns 200,000 acres of redwood timberland in Northern California, which includes the 3,000-acre Headwaters Forest, the largest privately held old-growth redwood forest. In addition to trees and lumber, the land is rich in water, wildlife and scenic vistas, all of which must be carefully managed and accounted for as public trust resources by its owner.
The company also has investors who want to know what's planned over the long-term to ensure a stable profit base.
Pacific Lumber has invested millions automating data about this forest and using ESRI GIS technology for long-term decision support to ensure minimal degradation to these public-trust resources. While the GIS data are useful for both economic and environmental studies, the graphics weren't "photo-realistic," - able to capture the imagination and communicate their intentions to the general public.
"The corporation felt responsible to make the information on this public-trust resource more accessible for general audiences," explains Dean Angelides, vice president of VESTRA. "We had to find better ways to portray the outcome of Pacific Lumber's planned activities-our answer was georendering."
VESTRA's analysts spent the better part of a year researching commercially available visualization and animation technologies that would scientifically mimic changes to a real-life landscape. The software would have to import GIS datasets supplied by Pacific Lumber from ARC/INFO and ArcView (ESRI, Redlands, Calif.) and produce lifelike images and animation sequences that could be integrated into a variety of multimedia applications.
Richard Baron, VESTRA's lead georendering analyst, who also has a fine arts background, spearheaded the research effort. "We'd been interested in visualization software for some time, but this was our first opportunity to combine photorealism with GIS on a project," he says.
An initial round of low-end rendering products were rejected because they couldn't support overlaying data. Next, the analysts tried to overlay color texture maps over 3D surface data from a DEM (digital elevation model) but found they could not reasonably render thousands of trees or a surface. Likewise, textured polygons did not deliver the photorealism required. "We were looking for technology able to mimic the look of trees and support data from the GIS," Baron says.
High-end visualization technologies from Silicon Graphics, Wavefront and Alias were explored as options, but their high price became prohibitive.
Through contacts made over the Internet newsgroups (www.alt.3D and alt.2D newsgroups), Baron was directed to an article describing several visualization packages, including World Construction Set (WCS) from Questar Productions (Brighton, Colo.).
WCS has been used extensively in the entertainment industry and computer games industry to create photorealistic graphics, but this is believed to be the first time it has been used for georendering in support of corporate sustainability studies.
For this project, VESTRA's analysts exported colored bitmap images from ArcView into WCS to create fully rendered "ecosystems" of three regions within the Pacific Lumber ownership. Fifteen ArcView files, each representing ecosystem conditions for a decade (a total of 150 years) were imported into WCS to create photorealistic renderings of a watershed. The WCS renderings were combined into a continuous sequence using morphing tools (Media Studio Pro 2.5, Ulead Systems) to smooth changes occurring between individual frames. This made it easier to follow tree density, vegetation, wildlife habitat, and other changes through time.
Explains Baron: "WCS uses each unique red/green/blue (RGB) value from the bitmap image as a match between a created ecosystem and the colored polygons. The ecosystems themselves are an assemblage of one or more photographic images, each representing a user-determined mix of tree, shrub and grass species. WCS's image placement are based on fractals. Each tree is drawn from bottom to top and placed randomly within the polygon to show the correct height and density.
WCS has sophisticated tools not only to specify height, density and species, but also render the landscapes with volumetric clouds, realistic lighting, water reflections and other effects.
WCS also lends itself to creating animation sequences with each ecosystem, perhaps showing the sun rising and setting, or the scene at different times of the year, or a flythrough.
The visualization package also lets analysts attach additional intelligence to the WCS ecosystems so they could indicate tree type changes for different elevation levels, aspect or slope.
The GIS images imported into WCS were used by Baron to generate ecosystem movies for each decade. The images were stored in .avi (Windows) files to run at 75 frames/5 seconds. Morphing tools were used to merge values between the frames, creating a smoothly flowing image throughout.
The WCS output was delivered to Pacific Lumber this summer for use in presenting their forest plans in public discussions and other forums where a lay audience needs to understand the long-term potential of the company's holding.
VESTRA sees this initial project done with WCS for Pacific Lumber as one of many where a combination of GIS and WCS would benefit clients in sustainability and other land planning studies. "Georendering is an emerging technology for improving relationships between geographic data and lifelike visualization," says Angelides. "Specifically, we see potential for using WCS with some of our agricultural clients, like the winegrape growers, who are looking for more realistic ways of portraying how their crops will develop through time," he says.
Visualization and virtual reality are emerging as the "common languages" we can all understand, he adds. "There's no chart, no graph or no map that conveys how the landscape will look in the future as quickly or effectively as these tools. Although ESRI's 3D Analyst (planned for release Q4 1997) will offer similar capabilities, this goes beyond the photorealism offered in ArcView."
While VESTRA has used WCS and GIS to produce preliminary graphics showing locations of prime vineyards within the Napa Valley, more work has to be done with the software to broaden its application, says Baron.
Baron is already exploring ways to make the technologies more useful to winegrape growers and for other land development projects, such as by adding objects into the file like buildings or wind machines, which would need to be shown in their true location within the scene. "That's what we're currently working on," Baron adds, "finding better ways to interchange information between GIS, WCS and other 3D rendering packages to expand interoperability of these tools."
According to VESTRA, this project, though an important milestone, is really just a taste of what georendering, the combination of GIS and visualization, can do for its clients and the GIS industry. About the Author:
Laura Lang is a freelance writer based in Ramona, Calif., whose work has appeared in national and international publications. She can be reached at 760-789-2989. Back |
