Hal V. Engel wrote: > On Sunday 19 August 2007 01:01, Harald JOHNSEN wrote: >> Hal V. Engel wrote: >>> I am not sure if the invisible tail is a flightgear problem, a problem >>> with the PC-7 model or if it is related to OpenGL or the nvidia drivers. >>> What I am seeing is that as I get closer to the aircraft ahead of me it's >>> tail starts to disappear and as I get even closer more of it will >>> disappear until it is totally gone. At one point I actually got in a >>> position where all I could see was the propeller and spinner which was >>> kind of interesting since I was behind the other aircraft. I would >>> estimate that my apparent distance from the closest part of the other >>> PC-7 when this screen shot was taken to be 50 to 75 feet. Since the >>> view is at a very wide angle things are much closer than they appear. >>> >>> I tried some tests with objects on the ground such as the hanger and the >>> two static aircraft (IE. the 747 that sits on the ground at KSFO) and >>> these did not show the issue. Then I tried the C172 that is always >>> located just off the end of 28L (mpdummy) and it also did not show any >>> signs of this issue. >> Hi, >> >> this is not a problem with the multiplayer aircrafts. You can see the >> same thing with your own aircraft. >> Change the view (v key), then adjust the view distance (with the dialog >> box). Your tail willl disapear, or your wing if you rotate the view. You >> did not witness this effect on the ground. >> I think that the code that computes the zbuffer range >> (http://www.sjbaker.org/steve/omniv/love_your_z_buffer.html) is >> outdated. The near clipping plane is set too far away and that's why the >> view is cut when in air. The problem is not visible when on ground >> because FG sets a 'better' Z-near value when under like 40 ft agl. >> Choosing values for the near/far clipping plane is not easy because this >> can lead to lots of visual artifacts. But I think that we could enhance >> the rendering a bit by reducing both the znear and the zfar values, zfar >> is set to a big number today for no apparent reason (why have a zfar set >> to 120km when the visibility is set to 17km ?). >> >> Sorry for the technical rambling... >> >> HJ. > > OK that sounds like a reasonable explanation that fits my description of the > problem well. Is there any chance that a fix for this will be in the next > release?
How much of a hit is there when changing zfar? (Assuming it can be done dynamically). Would it be possible to tie it to the visibility? Jon ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Flightgear-users mailing list Flightgear-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-users
