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SPT Loader

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Cquote1.png the whole LOD management needs to be reviewed and tweaked to get a bit more control, a (hopefully) simpler UI, plus the 'auto-LOD' I've suggested before. It's on my medium-term ToDo list, but definitely not short-term. If you find nasty things in the area of LOD, I would suggest recording / reporting them, but judge for yourself if it's worth investing time in making changes around the periphery. (Of course if anyone wants to really dive into that area I would be delighted, but best to sync up with Mathias about his SPT work, before writing any code).
— James Turner (2013-04-08). Re: [Flightgear-devel] A collection of questions.
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Cquote1.png I am sure Mathias can be asked for additional hints on the best way to integrate it. His SPT system replaces the tile-scheduling logic with the osgDB Pager, which improve various things, since osgDB would be fully in control of deciding what is loaded, and unloaded when, based on the camera(s) - no more arbitrary dealing with rings of tiles based on visibility parameters.
— James Turner (2013-09-18). Re: [Flightgear-devel] Upcoming Random Buildings changes.
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Cquote1.png the whole world model is already there.

There is the spt model loader that provides this. Load w180s90-360x180.spt
with fgviewer. That just happens when you call fgviewer without model (I
believe, since I have a much further developed version here). You need to
provide a property config that completely switches off shaders to see something
useful. But well, that's all in an early state...
This even works with different altitudes in between. The lod scales in between
need to be improoved. But this will happen gradually I think.


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Cquote1.png I have never described the spt loader, but it is able to provide a

scalable whole world paged scenery. This is similar to google earth or osg's
marble or the like. The scenegraph is done with a quadtree/octree structure
that in the end fits our tile structure of stg files. That should be fast to
cull. We have currently three levels of detail one of which with the recently
added earth texture and croaser tiles. One in between that still uses the same
texture but should use a set of higher detailed ones in the future. and the
third level then contains the stg files.


— Mathias Fröhlich (2012-03-24). Re: [Flightgear-devel] scenery loading cleanup.
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Cquote1.png So what needs to be done here is provide a set of earth textures for the mid

level of detail together with may be associated altitude textures for both
lod's. Then extend the croase ground tile implementation either in a vertex
shader or in static load time geometry generation to make use of the altitude
information. This could in a next step replace the high detailed btg/stg tiles
for far away tiles. And this should build the ground work for seriously enable
using really high detailed btg files but still being scalable.


— Mathias Fröhlich (2012-03-24). Re: [Flightgear-devel] scenery loading cleanup.
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Cquote1.png lease do not steer any lod ranges except may be the lod bias by any property.

That's again cross connecting code areas that do not need to be connected and
that then suffer from updates into the scene graph that are unneeded.
The osg LOD system is simple but effective if used in a sensible way.

The spt loader used in fgviewer also has lod hierarchies built in. You can
already load - may be I need to push this series to the latest version - lower
level of detail huger tiles if you put them into the right directories. That's
in preparation and has no upstream support form the scenery yet.


— Mathias Fröhlich (2013-02-22). Re: [Flightgear-devel] Low visibility issues.
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Cquote1.png our current model / scene hierarchy doesn't always use the OSG LOD system the best way, and that taking advantage of the LOD-bias feature would be very good. And hopefully quite a small, centralised change!
— James Turner (2013-02-22). Re: [Flightgear-devel] Low visibility issues.
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