Fly! II scenery editor - Question.

[Guest 3cffts]

Hi All, Question: Am I correct in thinking that the Fly! II scenery editor (Scenery editortoolsimport scenery) does not handle USGS 7.5min DEMs?When I try this I get a message "Unable to open DEM file".I am still trying to flatten TerraScene2 terrain for a runway that spans two globe tiles and need to use Flattenator. There is no "floating runway" problem at all with the default Fly! II scenery, just with the detailed TS. There is also a break half-way down the runway that prevents normal t/o and taxi. The built-in Fly Slicer will not fix the problem. Have tried many times! So I want to use Flattenator if it will load. Has anyone experience with Flattenator and 7.5min DEMs?.Brian.

[RandallR 444]

Brian,It is my understanding that TerraScene initiates this, but with the standard DEMs only. During slicing, TerraScene accesses the Fly!II Editor and the airport area is flattened to compensate. I believe that if a runway crosses a tile boundary, both tiles must be sliced as part of the project. I recommend complete Global Tiles for a project. Also, if the runway crosses a Global Tile boundary, that tile should be rendered and sliced as a separate project. With both scenery sets in place, that area should be flattened.Remember - the 7.5 DEMs can't be used directly by Fly!II! They can only be used by TerraScene and do not change elevations. They add the appearance of more depth to the rendered images with shadows along the crevasses and varying elevations - quite striking.

[Guest Colins2]

Brian / Randall,>>It is my understanding that TerraScene initiates this, but with the standard DEMs only.As I understand it, TS2 just translates the DEM data into a RAS file.The RAS file is simply a RASter scan, row by row of the data. This is what the Fly11 slicer needs.>>TerraScene accesses the Fly!II Editor and the airport area is flattened to compensate.As far as I'm aware this is a misconception.TS2 doesn't interact with Fly11 or the slicer in any way at all. In fact, apart from file formats, TS2 has nothing to with Fly and is really a stand alone program.What TS2 DOES do, and very well, is to create an image file of the selected area using as much geographically accurate (or fictitious) data as you feed it. The image file produced conforms to Fly11's implementation of Transverse Mercator projection. This is not a 'standard' projection but a compromise to project a moving image of almost any part of the globe as you 'Fly' over it.TS2 also produces a text file which the Fly11 slicer accepts as parameters for the slicing operation.>>I believe that if a runway crosses a tile boundary, both tiles must be sliced as part of the project. I recommend complete Global Tiles for a project. Also, if the runway crosses a Global Tile boundary, that tile should be rendered and sliced as a separate project. With both scenery sets in place, that area should be flattened.Makes sense. I'm not sure about runways crossing globe tile boundaries as I've never had to do one. The problem comes with the interpolation of the DEM data on the boundaries.>>Remember - the 7.5 DEMs can't be used directly by Fly!II! They can only be used by TerraScene and do not change elevations. They add the appearance of more depth to the rendered images with shadows along the crevasses and varying elevations - quite striking.Good point! I would just add that TS2 will translate the DEM data into the a/m RAS file which CAN be used by the slicer. TS2 uses the DEM model internally when applying the shading effects.To summarize:TS2 creates a very large, geographically correct image in the projection that Fly11 uses and also, if asked to, will produce a RAS file from DEM data in the format that the slicer can understand but NOT as a Fly11 grid.The slicer then does all the donkey work of carving up this image into the 64 x 64 grid of ground tiles making sure that the transitions between the tiles are as seamless as possible. It will also interpolate the DEM data from the raster file into it's own grid structure. These two processes are quite different.When the slicer comes to a globe tile boundary it has to interpolate the DEM data to fit in with the underlying global elevation model so that the transition from user data to default data is as seamless as possible. The flattening procedure is part of this interpolation and involves the slicer accessing the airport and runway pods to get the 'local' data.I am not sure about runways that cross globe tile boundaries but I would suggest that if the globe tile that actually holds the airport is rendered first then the subsequent adjoining tile 'might' be interpolated to match.Failing that there are a couple more options to try.Just import the images first for each tile and let the slicer do it's thing. Then feed the slicer with the DEM data to cover the complete 2 globe tiles.The only other solution I could think of is to create a dummy airport in the second tile with the reciprocal runway only and see if that works. You can try this without going through the whole slicing process by simply applying the DEM data to the area and trying to taxi along all the runways.The main thing is that the image data and DEM data are 2 totally different things. The image is 'draped' over the 3D terrain model created from the DEM data. The runways are just another model placed on the surface of the terrain model.If you want to translate the DEM data yourself just do a search for "DEM2RAS". It should be in the library somewhere. This will give you the raw data to play with.I hope this helps a bit.Colin

[RandallR 444]

Colin,Thanks for the input! We are on the same page here, but I was a little simplistic. I was attempting to state that DEM data for elevations gathered by TS2 is supplied to Fly!II. Elevations will change and the airport area, if part of the project, should be flattened.A good example of this for me would be a project I finished a while ago on a global tile on the border of South Carolina and Georgia. Included in this project was the Savannah, GA airport. Before I TerraScened the area, I had updated the airport with a scenery package from Wayne Roberts, which included dynamic vehicles. The vehicles moved along paths that were also defined by the terrain elevation. After TerraScening, with the new elevations applied, the dynamic vehicles were running at the old elevation, appearing half buried in the runways and tarmacs. I removed them. The buildings, however, sat on top of the new elevation properly, and the airport had no flattening issues.Brian, not only would I recommend projects be global tile in size, but make sure that "snap to grid" is turned on to make sure that border areas will be proper.