besides everything said, this nails it down : "... but declaring the Metaverse to simply end at 0 seems very random. " I should make this my new email signature .. well said, Jim .. it's the metaverse .. no boundaries ? with future physics not working below -0 ther will be no underwater worlds .. no submarines .. even boat creators must keep an eye that the engine does not move below -0 ; ? best regards Wordfromthe Wise
_____ Von: [email protected] [mailto:[email protected]] Im Auftrag von Jim Williams Gesendet: Freitag, 25. April 2014 02:17 An: [email protected] Betreff: Re: [Opensim-dev] Negative z values Seems to me that 0 is a completely arbitrary number and that a cut-off for any reason other than hardware/mathematical limitations is unwarranted. I could see taking an "oh well" attitude about things that don't work with -z, but declaring the Metaverse to simply end at 0 seems very random. On Thu, Apr 24, 2014 at 6:46 PM, Melanie <[email protected]> wrote: I have never seen a Z < 0 build. I see lots of problems that may be possible with this, but I think that quite beautiful and interesting builds could make use of this and would support keeping it. The change in the viewer is recent and likely trivial to undo. - Melanie On 25/04/2014 00:32, Justin Clark-Casey wrote: > Hi folks. Historically, whether by accident or design, OpenSimulator has allowed negative Z values for terrain, objects > and avatars (e.g. <130, 50, -45>. I have seen people use this facility to build fully underwater or partially > underwater structures (e.g. oil rigs, sunken ships, etc.) which are conceptually far below the water line without having > to set that water line at a level that may be way above that of surrounding regions. > > However, at least on Singularity 1.8.5 on Linux, fog effects do not work properly when z < 0, where all view distances > have very high fog no matter what the fog settings. This may be a recent change - I remember fog working properly at > negative z values in the past, though the fog issue still occurred past a certain -ve z. There may be other issues of > which I'm not aware. Arguably, these are not bugs since the Linden Grid does not allow z < 0 (though one could make the > same argument for var regions, etc.). > > With in-world testing of current development code, BulletSim appears to have a hard-coded check where I can't move my > avatar below z == 2 whether terrain is z < 0 or not (this should probably at least be fixed so z = 0 is possible). ODE > has allowed and still allows the avatar to descend to negative depths. > > One argument is that in the light of such bugs, it would be better to consistently enforce z >= 0 and require people > with -z builds to either move them and the water level up using OpenSimulator commands (e.g. "translate scene") or never > update their OpenSimulator installation. > > However, I think there is a real value in keeping the -ve z ability. It allows people to extend deep water builds > without having to adjust any neighbouring sims for consistency (which they may not have control over). I'm sure it's > possible to address the viewer-side issues. OpenSimulator could have an allow-negative-z flag which is false by default > to make it explicit that using -ve z may have issues at this time. I accept this is a more complicated solution than > enforcing z == 0, though enforcing z == 0 will also requires many changes to the current code where bounds are not checked. > > If my experience is unusual and -z builds are very rare then there's more of a case for enforcing z >= 0. > > Thoughts? > _______________________________________________ Opensim-dev mailing list [email protected] http://opensimulator.org/cgi-bin/mailman/listinfo/opensim-dev -- No essence. No permanence. No perfection. Only action.
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