Yes sorry, I meant 50 - I get confused since the lower number is more 
compression.

I would like to revert my in-memory short -> int change and double the compression instead. However, this would mean a terrain height resolution of 2cm. Even though the weakest terrain tool changes in my testing are orders of magnitude greater than this resolution, I'm still concerned about the effect on existing terrains where objects may have been positioned very accurately or where physics may be a factor.

At this point, >327m heights will now work again on 256x256 regions because of their legacy approach of storing terrain data in doubles. However, varregions will still not work with >327m heights because they use Int16 for storage and I haven't changed that.

As varregions are new in this release and have never previously worked with >327m heights, I propose to leave that as the case for now. I do think this is less than ideal, as it means different limits on 256 and varregions (not that we actually police limits), but changing the storage format is not something that I want to do at this release stage and I know quite a few of your concerns centred around this.

It also struck me that if one is using ints then it would make more sense just to use floats. However, I'm trying to do the minimal code changes necessary right now and I was concerned about introducing bugs on double -> float conversions (e.g. [1]).

Also, I want to apologise if you're unhappy that I went and introduced this change without talking with you further. Ordinarily, I would have done this but I was under the impression that you would be away for a while and not picking up e-mail. I was anxious to get the remaining major issues squashed to make the first release candidate possible so just took the plunge. Possibly this was the wrong decision.

[1] 
http://stackoverflow.com/questions/6640742/convert-double-to-float-without-infinity

Regards,

Justin

On 29/04/14 23:53, Mister Blue wrote:
if the variables are going to stay ints, then 200 would just mean more detail.

Actually, if you are going to use ints, might as well go to floats and use a 
compression factor of one. That would give
the range people want and use the same memory as ints.

-- mb


On Tue, Apr 29, 2014 at 12:39 PM, Justin Clark-Casey <[email protected] 
<mailto:[email protected]>> wrote:

    Sounds good.  On another topic, any further thoughts about using a 
compression factor of 200 on terrain for this
    release?


    On 29/04/14 03:29, Mister Blue wrote:

        I checked in changes to BulletSim which default the ground plane to 
-500 instead of zero. There is a new BulletSim
        parameter of "[BulletSim]TerrainGroundPlane = -500" which allows that 
to change.

        I haven't yet finished looking through the terrain loading and storing 
code so there could still be problems with
        loading and restoring negative terrain heights, but it looks like the 
code will work once you get the terrain
        negative.
        Please test.

        If found in my testing that there are checks for zero scattered around 
OpenSimulator. For instance,
        LowerSphere.cs (the
        terrain brush used for lowering terrain) will not lower terrain below 
zero.

        -- mb


        On Mon, Apr 28, 2014 at 3:05 PM, Justin Clark-Casey <[email protected] 
<mailto:[email protected]>
        <mailto:jjustincc@googlemail.__com <mailto:[email protected]>>> 
wrote:

             I don't think there should be too many places.  I know there are a 
few on teleport and MakeRootAgent (as Austin
             pointed out) but it looks like it should be fairly simple to check 
real terrain height, which might already
        be done
             anyway and be masked by the zero check.

             It does work in general as it has been possible with ODE.


             On 27/04/14 18:13, Mister Blue wrote:

                 When I built BulletSim, I build for positive only altitudes 
because I thought that was the rule. The only
                 implementation
                 reason I see for not allowing negative terrain altitudes would 
be finding all the random places where
        code makes
                 sign
                 assumptions.

                 If negative altitudes are needed, it would not be too hard to 
make it happen. I can see the
        geographically oriented
                 people wanting zero to be sea level and allowing land to be 
above and below that.

                 -- mb


                 On Sat, Apr 26, 2014 at 8:11 AM, Cinder Roxley 
<cinder.roxley@phoenixviewer.____com
                 <mailto:cinder.roxley@__phoenixviewer.com 
<mailto:[email protected]>>

                 <mailto:cinder.roxley@ <mailto:cinder.roxley@>__phoeni__xviewer.com 
<http://phoenixviewer.com>
        <mailto:cinder.roxley@__phoenixviewer.com 
<mailto:[email protected]>>>> wrote:

                      Given reasonable constraints, I don't see why viewers 
wouldn't be able to adapt to support
        variable depth. I'd
                      certainly be willing to write a viewer patch if support 
cropped up.


                      On Sat, Apr 26, 2014 at 8:52 AM, David Saunders 
<[email protected]
        <mailto:[email protected]> <mailto:[email protected] 
<mailto:[email protected]>>
                 <mailto:[email protected] <mailto:[email protected]> 
<mailto:[email protected]
        <mailto:[email protected]>>>__> wrote:

                          I wounder how hard it would be to modify varasm to 
allow a start and end to the Z axes so we
        can stack
                 a deep
                          ocean and a space sim to the normal sim :)

                          But then again would the client handle all these 
changes? (partly do)

                          So the solution is to make deep water simulators, But 
any test this? I never been asked to set
        up any
                 sims with
                          deep water so I not experience with "outside the box" 
water :)

                          I was drawn to opensim with the idea of making "pure" 
space sims where you can float around in
        real
                 space but I
                          dug into it and I would have to rewrite so much code 
to do this and after that  would the
        client handle
                 it? So I
                          stuck with making Moon simulators, Low gravity fixed 
sky....   This was a long time ago,  back
        in the
                 early days
                          of opensim.

                          Now times are changing, I think I might dig into 
doing it again since  varasim allow you to make a
                          4096x4096x4096 regions :)



                          On Sat, Apr 26, 2014 at 4:18 AM, Ai Austin 
<[email protected]
        <mailto:[email protected]> <mailto:[email protected] 
<mailto:[email protected]>__>
                 <mailto:[email protected] <mailto:[email protected]> 
<mailto:[email protected]
        <mailto:[email protected]>__>__>> wrote:

                              At 04:09 26/04/2014, drWhiet wrote:

                                  even boat creators must keep an eye that the 
engine does not move below -0


                              Remember the default water level is +20m (adjustable on a 
per region basis)... with a "normal"
                 terrain base
                              of 0m.

                              Maybe its global warming in the metaverse that 
raised the sea level :-)




                              
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