dene maxwell wrote: > Hi Josh > > >> From: Josh Babcock <[EMAIL PROTECTED]> >> >> dene maxwell wrote: >> > Hi Josh >> > I posted on this subject a couple of weeks ago.... there was some >> > discussion as to where the "scaling" of the texture was done >> > Terragear/FlightGear. There were two points; >> > >> > 1) ... when viewed from above a 45deg slope will only seem 0.7071 of >> its >> > true length. Hence a "stretching" issue when viewed from the side. >> > >> >> I was thinking more of stuff between 70 and 90 deg, places that are >> steeper than the angle of repose and would never have trees, let alone >> soil on them. This foreshortening is exactly what happens in real life >> when you look down at a cliff, and it would be appropriate to see the >> same in FG. In fact, the current situation that we currently experience >> in steep areas is a very exaggerated version of the problem that you >> describe. >> > True, the steeper the slope, the more exaggerated the problem. Do you > agree there are two issues, the stretching and the appropriateness of > the face material (ie does your comment " irrigated fields stretched up > a hillside" recognise both issues ro do you see them as one in the same > thing?)
Oh, I definitely agree that there are two issues here. Having inappropriate textures on steep terrain is probably the easier one to fix. Once that happens, it should be possible to improve how those new textures look by changing the way they are mapped onto the terrain. > >> > 2) ... the current terrain is designed to be seen from above... When >> > viewing terrain from the side other factors come into play...your >> > stratum idea and the one I put forward where urban terrain is presently >> > designed from a "birds eye view" ie roof's, when this is viewed from >> the >> > side it should be walls and windows, the roofs always being on the >> > uphill side. This implies left and right handed scenery amongst other >> > perspective issues. >> > >> >> Personally, I like to fly in mountainous areas, ..... > > > my landings need too much practice to skive off and enjoy the scenery <g> Yes, takeoffs are optional, landings are mandatory. > >> .....and I often find myself >> looking sideways at a cliff. Again, I am not talking about flat terrain, >> but vertical terrain. It really ruins the illusion when can look >> sideways at an irrigated field that has been stretched up the >> mountainside. >> >> My point is that perhaps some of the terrain should be designed to be >> viewed from the side, and not above. The trick is teaching terragear to >> determine what that terrain is and assign it a new landcover type: cliff. >> > > .. Agreed; cliff, "right" hilly urban and "left" hilly urban. I'm sure > others will come up with other landcover types. I'm not sure what you mean by right and left. Keep in mind that this is not done at run time, but during scenery generation. Whatever terragear lays down has to look right from every angle. I would also include "scree slope", "river rapids" and "waterfall". There may be a way to do terraced farmland, but that seems like it would get complicated. > > It would be nice if Terragear was able to this automatically, as an > interim solution, if the landcover types were available in FGSD users > could customise areas that they want. Is it hard to add landcover types? > Are there any other issues that I'm not aware of? I don't think so, there are a lot in the raw datasets that are currently ignored just for lack of textures. The harder part would be to have terragear assign new ones on it's own based on the slope angle and the original landcover data in the raw dataset. > >> Since a picture is worth a thousand words, here's two thousand: >> http://jrbabcock.home.comcast.net/flightgear/one.jpg >> http://jrbabcock.home.comcast.net/flightgear/two.jpg > > > I think your pics beautifly summarise all the words written on this > subject. Thank you. > >> >> > Sort of associated with your river issue is the issue of railways and >> > the sections of railways that are through tunnels.... this particularly >> > effects me as two of the longest rail tunnels in the southern >> hemisphere >> > are in my local area and it looks silly to have them placed on the >> > surface climbing 60deg slopes .... I have talked to Fred about being >> > able to resolve this in FGSD but no firm answer yet. >> >> The first step would be to find a dataset that shows where the linear >> features are not on the surface. This is the same issue as with bridges. >> If we can find a dataset that represents this like topographic maps do, >> it will be a piece of cake to have automatically generated bridges and >> tunnels. >> > That would be great. > >> Josh >> >> > >> > Cheers >> > Dene >> > >> >> From: Josh Babcock <[EMAIL PROTECTED]> >> >> >> >> I. Currently the terrain textures are UV mapped onto the terrain from >> >> directly above. This creates all sorts of problems in steep >> terrain. One >> >> of those problems is that cliffs and near cliffs look really bad. >> >> Perhaps if terrain with a slope greater than a certain threshold >> were to >> >> be mapped from the side with a texture bearing strata this particular >> >> case would start to look right. What would be involved in making >> >> particular terrain types be mapped differently? >> >> >> >> II. Another thing I have been thinking about since the new scenery was >> >> released is flattening rivers. The new algorithm certainly makes >> places >> >> like the Grand Canyon look a lot more like they should, but there are >> >> still a lot of rivers that travel up and down like roller coasters. >> >> Perhaps if once the linear database is in sync with the elevation data >> >> it would be a good idea to tell the algorithm where the rivers are >> so it >> >> can increase the number of vertecies along the rivers. On the other >> >> hand, maybe simply getting the linear feature data in the same >> place as >> >> the elevation data will be all that it takes. >> >> >> >> A really smart algorithm would also be able to see when it is laying >> >> down a river on a slope and move it to the bottom of the valley. It >> >> might even be able to figure out the registration error between the >> two >> >> datasets this way and automatically adjust for that. >> >> >> >> Josh >> > >> > > > > _________________________________________________________________ > Read the latest Hollywood gossip @ http://xtramsn.co.nz/entertainment > > > > ------------------------------------------------------- > This SF.net email is sponsored by: Splunk Inc. Do you grep through log > files > for problems? Stop! Download the new AJAX search engine that makes > searching your log files as easy as surfing the web. DOWNLOAD SPLUNK! > http://sel.as-us.falkag.net/sel?cmd=lnk&kid=103432&bid=230486&dat=121642 > _______________________________________________ > Flightgear-devel mailing list > Flightgear-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/flightgear-devel > ------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. 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