Michele, Yours is the most appropriate approach. There isn't a way to do what you want with an existing higher-level construct.
I developed a similar capability in a client application; we call it a a "track history". You are correct that localizing the geometry will eliminate jitter; however, if the track is long enough, you will need to break the track into multiple chunks and localize each chunk. By the way, there is a forum/list specifically for osgEarth-related questions: http://forum.osgearth.org Good luck! Glenn Waldron On Wed, Apr 20, 2016 at 3:38 AM, Michele Onnis <michele.on...@gmail.com> wrote: > Hi, > > I'm using the osgEarth library and I'm trying to draw Time Space Position > Information datasets with a playback functionality. I want to draw the > whole trajectory and then draw a subrange of the SAME trajectory, with a > different style, for playback purposes: the playback subrange is > "translated" over time to achieve the animation playback. > > In the first approach, I used two different node graphs based on > osgEarth::Feature classes (Feature / Session / FeatureSource / > FeatureModelGraph). I wanted to share the feature and specify two different > draws of same feature (total range and partial range), but I could not find > a way to do this. So, at every frame I add geometry to the playback feature > and this action drops the framerate. > > To solve the problem, I've tried to switch to a "lower level" > implementation based on osg::Geometry. In this case, I share the vertex > array between the whole trajectory and the playback trajectory, then I > specified two DrawArrays with different ranges for the different renders. > The performance of this solution is perfect, but the geometry shows jitter > problems related to the single precision of the GPU (geometry is specified > in world coordinates). > > I know that in the second scenario I have to "localize" the geometry in a > local origin to minimize the jitter, but I ask if there is a way to achieve > the same results with the "higher level" approach (osgEarth::Feature > classes), because I'd rather take advantage of all optimizations in this > classes. So, how can I specify a single Feature and then specify multiple > renders of the same Feature, with different ranges of the data and > different styles? > > Thank you! > > Cheers, > Michele > > ------------------ > Read this topic online here: > http://forum.openscenegraph.org/viewtopic.php?p=66886#66886 > > > > > > _______________________________________________ > osg-users mailing list > osg-users@lists.openscenegraph.org > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >
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