[osg-users] PIXEL_SIZE_ON_SCREEN And RangeList of osgb file

[Andreas Ekstrand]

Hi Mouming,

With PIXEL_SIZE_ON_SCREEN the specified ranges describe the size in 
pixels of the PagedLOD's bounding sphere. So in your case, when it's far 
away and occupies 0 - 1293 pixels (e.g. 300), the first child is shown, 
i.e. the geometry directly beneath the PagedLOD - no filename is 
specified for the first range. When you get closer it occupies 1293 - 
1e+030 pixels (e.g. 20000) and the specified 
Tile_050_050_L21_000000000.osgb, which should be more detailed, is 
loaded as specified as the second range.

I was under the impression that it uses the bounding sphere diameter in 
pixels but now that I looked more closely I can see in 
CullingSet::pixelSize where it all boils down that it seems to relate to 
the radius instead. Someone more knowledgeable can certainly comment on 
this, as well as the priority offset and scale specified by the 
PriorityList, it's probably some kind of local LOD scale?

Regards,
Andreas


On 2018-01-11 02:42, Mouming Ning wrote:
> Hi,
>
> my osgb's "head" is like this:
>
> osg::PagedLOD {
>    UniqueID 1
>    CenterMode USER_DEFINED_CENTER
>    UserCenter -1619.41 -187.445 1047.71 40.4089
>    RangeMode PIXEL_SIZE_ON_SCREEN
>    RangeList 2 {
>      0 1293.08
>      1293.08 1e+030
>    }
>    DatabasePath TRUE "D:\\Tile_050_050/"
>    RangeDataList 2 {
>      ""
>      "Tile_050_050_L21_000000000.osgb"
>    }
>    PriorityList 2 {
>      0 1
>      0 1
>    }
>
> My problem is that  how the rangelist correspond to the pixel size on screen?
> such as the pixel size is 1300,then this osgb is display on the screen?but when the pixel size is 300,then what will happen?? or 20000,what will happen??
>
> Another question is that what's meaning of PriorityList?? What is it used for ??
>
> Thank you!
>
> Cheers,
> Mouming
>
> ------------------
> Read this topic online here:
> http://forum.openscenegraph.org/viewtopic.php?p=72719#72719
>
>
>
>
>
> _______________________________________________
> osg-users mailing list
> osg-users at lists.openscenegraph.org
> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openscenegraph.org/pipermail/osg-users-openscenegraph.org/attachments/20180113/98992936/attachment.html>