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Talk:Particle system

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Issues & Development

ticket 305

Cquote1.png I have been unable to run FG with particles enabled since a long time due to random crashes in the particle code.
— Csaba Halász (Aug 1st, 2011). Re: [Flightgear-devel] startup crash in SimGear (with patch?).
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Cquote1.png I actually had it disabled for a long time. After enabling it recently, I also started having memory issues
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Cquote1.png Drawback with our current codebase: Our integration of the particle systems need to be rethought as this contains geometry with culling disabled which makes a pagedlod just never expire. Switching the particle systems off works pretty good so far.
— Mathias Fröhlich (Jul 21st, 2012). Re: [Flightgear-devel] Rendering passes question.
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Cquote1.png IIRC each particle > system is attached to the scene graph in (at least) two places: at the > emitter's location in the graph and in a global vector of particle system > updaters. IIRC they are never removed from the global list of updaters > (a bug - but a hard one to fix due to concurrency issues). > Tim knows more about this.
— Anders Gidenstam (Apr 16th, 2011). Re: [Flightgear-devel] OSG caching.
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Cquote1.png If I'm not mistaken the particles issue has been around since we got particles, so it is apparently not that bad (leak and race condition) in practice.
— Anders Gidenstam (Apr 16th, 2011). Re: [Flightgear-devel] OSG caching.
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Cquote1.png I guess the issues with "Effect" objects is probably worse than with particles. There's a larger number of Effect objects - and each is connected to a texture (.rgb/.png images) - which may occupy a lot of memory. Just by starting at KSFO, loads of KSFO terminal textures - and textures of 15 different MP aircraft immediately stick in memory...
— ThorstenB (Apr 16th, 2011). Re: [Flightgear-devel] OSG caching.
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Cquote1.png Regarding precipitation - the current particles code in Simgear has major performance problems - and some outright mistakes in its implementation. Notably the animation of the particles is done in the wrong phase of OSG’s frame loop, which can prevents particle animations being unloaded - i.e can cause tiles to never be unloaded. For this reason many people have been disabling particle effects to ensure stable frame-rates. However, the complication is the Simgear particle system is effectively a fork+edit of the osgParticle system, which I think is what we use for precipitation. Ideally we’d use the osgParticle system everywhere (since it has correct interactions with the rest of OSG) but it also has the issues about customising the rendering you mentioned. (I don’t think the Simgear particles are any better in that regard, but I may be wrong)
— James Turner (Oct 13th, 2014). Re: [Flightgear-devel] Precipitation issues.
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