This is a good fix (thanks for doing it Melanie!). And, so long as it isn't back-patched into an existing release, only affects people when they upgrade to the *next* release (or those who track daily... and they get what you would expect... daily changes).<div>
<br></div><div>--mic</div><div><br><br><div class="gmail_quote">On Sun, Dec 4, 2011 at 11:42 PM, Melanie <span dir="ltr"><<a href="mailto:melanie@t-data.com">melanie@t-data.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
As I am the one who did it, +1 on leaving it fixed. Items can be<br>
fixed and copy/paste compatibility for new objects coming in from sl<br>
is more important, IMHO.<br>
<br>
Melanie<br>
<div><div class="h5"><br>
On 05/12/2011 04:14, Trinity wrote:<br>
> i say fix it and let the chips fall where they may<br>
><br>
> On Fri, Dec 2, 2011 at 3:55 PM, Justin Clark-Casey <<a href="mailto:jjustincc@googlemail.com">jjustincc@googlemail.com</a><br>
>> wrote:<br>
><br>
>> OpenSimulator commit b6df9e9 (dev code) changed the sit target adjustment<br>
>> to better match that used in Second Life.<br>
>><br>
>> Unfortunately, this has the effect of making all existing sit positions<br>
>> set by scripts using llSitTarget() inaccurate (e.g. avatar ends up hovering<br>
>> above a chair).<br>
>><br>
>> From a user/scripter point of view this is a bad thing. Not only do<br>
>> existing objects with user inventory/prim inventory now have wrong values,<br>
>> but positions loaded from OARs/IARs will now be wrong without adjustment,<br>
>> and OARs/IARs saved in dev code or future 0.7.3 will have wrong sit values<br>
>> when loaded into older OpenSim releases.<br>
>><br>
>> However, I believe that's it's practically impossible to have old objects<br>
>> correctly use the old sit adjustment and new objects the new one. Here are<br>
>> the alternative courses of action and my considered pros/cons of each<br>
>><br>
>> 1. Change sit adjustment with no other action.<br>
>> PROS: llSitTarget() is now implemented correctly. No legacy mess in the<br>
>> code. No extra complexity required. No development work required.<br>
>> CONS: Without adjustment, all region, inventory objects and scripts now<br>
>> use wrong sit values. Wrong sit values in OARs and IARs. Wrong sit values<br>
>> when OARs/IARs/objects moved between dev/future 0.7.3 versions and older<br>
>> OpenSim versions.<br>
>><br>
>> 2. Provide a tool to correct sit values in scripts<br>
>> CONS: Too difficult since requires massive amount of script analysis.<br>
>> Might be possible in a limited way to catch 80/20 cases.<br>
>><br>
>> 3. Use different sit adjustment depending on prim creation date (pre Sat<br>
>> 5 Nov 2011 use old value).<br>
>> PROS: Stops older sit positions from being wrong. Doesn't require much<br>
>> code change.<br>
>> CONS: A user has to know an opaque magic date when the sit position<br>
>> changed. Somewhat messy legacy code. Future upgraders from 0.7.2 will get<br>
>> some prims with 'wrong' sit positions and others with 'right' depending on<br>
>> when they were created, which is in the long term possibly more confusing<br>
>> than everything needing adjustment.<br>
>><br>
>> 4. Revert llSitTarget() behave and create an osSitTarget() using the new<br>
>> adjustment instead.<br>
>> PROS: All existing sit targets continue to be 'correct', and old scripts<br>
>> still work correctly in new objects.<br>
>> CONS: llSitTarget() remains wrong for all time (could warn on use and<br>
>> eventually change, but users don't pay attention to such warnings).<br>
>><br>
>> 5. Store new sit positions in a different field on SOP and use this if<br>
>> present with new sit adjustment, otherwise use old field with old sit<br>
>> adjustment.<br>
>> PROS: Works invisibly as long as old scripts don't set new values.<br>
>> CONS: Messy legacy code. Old scripts probably will set new values - then<br>
>> would need to act differently on script item creation date, with same<br>
>> issues as 3.<br>
>><br>
>> 6. Provide a config switch to use old sit adjustment or new.<br>
>> PROS: Administrator controllable. In a future OpenSim release, admin can<br>
>> decide when they are going to flip to using the 'new' value. This might be<br>
>> done anyway for the use case where OpenSim is being used with content in<br>
>> isolation from elsewhere.<br>
>> CONS: Encourages the creation of more objects using the old sit values,<br>
>> encouraging a continuous mix of old and new values which can't both be used<br>
>> on the same region.<br>
>><br>
>> Doubtless there are other strategies, but on the face of it there doesn't<br>
>> seem to be an ideal solution. It's made much more difficult by the fact<br>
>> that these values can only be scripts rather than as properties on the part<br>
>> (a decision which I find hard to swallow).<br>
>><br>
>> On the whole, I think that it's better to accept the pain of change as<br>
>> early as possible and move to a world where all values are correct rather<br>
>> than remain with one where things are incorrect or a mish-mash in the long<br>
>> term. As I said to Akira, the alpha nature of OpenSim is meant to be a<br>
>> signal that these things can change as bugs are fixed.<br>
>><br>
>> However, I'm certainly happy to hear alternative opinions or<br>
>> well-researched and intelligent alternative proposals.<br>
>><br>
>> --<br>
>> Justin Clark-Casey (justincc)<br>
>> <a href="http://justincc.org/blog" target="_blank">http://justincc.org/blog</a><br>
>> <a href="http://twitter.com/justincc" target="_blank">http://twitter.com/justincc</a><br>
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