On mer 13 août 2008, Vivian Meazza wrote:
> gerard robin wrote:
> > Are we sure that, all the Particle features which are within OSG, are
> > available with the new XML coding <particlesystem> ?
> >
> > When translating one of my .osg file to <particlesystem> .xml file, i
> > don't
> > get the same quality of result.
> >
> > It could be just me. I can be wrong. :(
> >
> > Or that new XML coding is may be a first step, and others improvements
> > are coming :)
>
> No, all the features of particles are not available with the xml version,
> but I don't think that should affect performance.
>
> Tim recently fixed a bug which only showed up under MSVC9, and other bugs
> have been reported, in particular that the particles "jitter".
>
> There are no further enhancements planned to the xml stuff that I am aware
> of, unless Tiago is doing something.
>
> What exactly is the problem?
>
> Vivian
Hello Vivian , nice to read you
Here are the snapshots which show the difference with Catalina model
I have done the test on the left float only.
In order to get the <particlesystem> file, i translated the .osg file to the
new xml file. (same parameters, when available)
First with the .osg model
http://pagesperso-orange.fr/GRTux/OSG_ModelParticle-Img1.jpg
http://pagesperso-orange.fr/GRTux/OSG_ModelParticle-Img2.jpg
Second with the xml file <particlesystem> from Tiago developement
http://pagesperso-orange.fr/GRTux/OSG_XMLParticle-Img1.jpg
http://pagesperso-orange.fr/GRTux/OSG_XMLParticle-Img2.jpg
In addition to, we can notice that the <particlesystem> doesn't mind with
the "hide" feature, we can see the effect through the wing on the top view,
the .osg model take care of it, with respect of the hierarchy, objects
behind, objects in front of (seems to be the same problem with the new Rain
feature, raining can be seen in the cockpit :( )
Is it a bug ?
Regarding the eye candy difference, it is sure that i can try to improve with
others parameters, and with some additional cumulative effects (3, 4 , 5
effects on the same starting point).
I fear that the cpu would be overloaded, quickly
However, i can see an advantage to the <particlesystem> :) :
it follows the trajectory of the source, which is significant when the life
time is long.
Here are the osg files and the resulting xml file <particlesystem>
You can notice that that .osg file is very simple, it does not use the full
featuring that we can use with it, it could be more complex, and an expert (i
am not) could get with it more and more realistic effects.
So the <particlesystem> ( in spite of the good work which has yet been done by
Tiago) to me, will need more and more improvements in order to use fully that
nice OSG system.
Regards
--
Gérard
http://pagesperso-orange.fr/GRTux/
"J'ai décidé d'être heureux parce que c'est bon pour la santé.
Voltaire "
//Gerard Robin 03-02-2007 FlightGear Copyright License: GPL
Group {
UniqueID Group_20
DataVariance DYNAMIC
name "catalina_flux1.osg"
nodeMask 0xffffffff
cullingActive TRUE
num_children 3
osgParticle::ModularEmitter {
UniqueID ModularEmitter_23
DataVariance DYNAMIC
name "ModularEmitter2"
nodeMask 0xffffffff
cullingActive FALSE
osgParticle::ParticleSystem {
UniqueID ParticleSystem_24
DataVariance DYNAMIC
StateSet {
UniqueID StateSet_25
DataVariance STATIC
rendering_hint OPAQUE_BIN
renderBinMode USE
binNumber 0
binName RenderBin
GL_LIGHTING OFF
GL_COLOR_MATERIAL ON
GL_BLEND ON
textureUnit 0 {
GL_TEXTURE_2D ON
Texture2D {
UniqueID Texture2D_26
DataVariance STATIC
wrap_s CLAMP
wrap_t CLAMP
wrap_r CLAMP
min_filter LINEAR
mag_filter LINEAR
maxAnisotropy 1
borderColor 0 0 0 0
borderWidth 0
useHardwareMipMapGeneration TRUE
unRefImageDataAfterApply FALSE
internalFormatMode USE_IMAGE_DATA_FORMAT
resizeNonPowerOfTwo TRUE
}
TexEnv {
UniqueID TexEnv_27
DataVariance STATIC
mode MODULATE
}
}
}
supportsDisplayList FALSE
useDisplayList FALSE
useVertexBufferObjects FALSE
particleAlignment BILLBOARD
alignVectorX 1 0 0
alignVectorY 0 1 0
doublePassRendering FALSE
frozen FALSE
freezeOnCull TRUE
defaultBoundingBox -10 -10 -10 10 10 10
particleTemplate {
shape QUAD
lifeTime 4
sizeRange 0.35 0.2
alphaRange 0.5 0
colorRange 0.440696 0.504509 0.53962 0.8 0.0784009 0.535637
0.540536 1
position 0 0 0
velocity 0 0 0
angle 0 0 0
angularVelocity 0 0 0
radius 0.8
mass 0.8
textureTile 1 1 1
sizeInterpolator {
osgParticle::LinearInterpolator {
UniqueID LinearInterpolator_28
DataVariance DYNAMIC
}
}
alphaInterpolator {
osgParticle::LinearInterpolator {
UniqueID LinearInterpolator_29
DataVariance DYNAMIC
}
}
colorInterpolator {
osgParticle::LinearInterpolator {
UniqueID LinearInterpolator_30
DataVariance DYNAMIC
}
}
}
}
enabled TRUE
referenceFrame ABSOLUTE
endless TRUE
lifeTime 0
startTime 0
currentTime 0
resetTime 2
useDefaultTemplate TRUE
osgParticle::RandomRateCounter {
UniqueID RandomRateCounter_31
DataVariance DYNAMIC
rateRange 80 80
}
osgParticle::SectorPlacer {
UniqueID SectorPlacer_32
DataVariance DYNAMIC
center 0 0 0
radiusRange 0 0.35
phiRange 0 6.28319
}
osgParticle::RadialShooter {
UniqueID RadialShooter_33
DataVariance DYNAMIC
thetaRange 0 0
phiRange 0 0
initialSpeedRange 4 5
initialRotationalSpeedRange 40 0 0 70 0 0
}
}
osgParticle::ParticleSystemUpdater {
DataVariance DYNAMIC
name "ParticleSystemUpdater6"
nodeMask 0xffffffff
cullingActive FALSE
Use ParticleSystem_24
}
Geode {
DataVariance DYNAMIC
name "geode1"
nodeMask 0xffffffff
cullingActive TRUE
num_drawables 1
Use ParticleSystem_24
}
}
<?xml version="1.0"?>
<!--Document started 27/01/2008 by Tiago Gusm�o
Updated 02/02/2008 to reflect syntax changes
Updated 03/02/2008 to add trails (connected particles)
This is a short specification/tutorial to define particle systems in FlightGear using XML
Stick this inside any model XML like it was an animation and it should work (notice the condition requires wheel on the ground)
Specification:
Note:-->
<!--<VALUEORPROP/> means you can either specify a property with factor and offset (result = (prop*factor)+offset ) in the usual way-->
<PropertyList>
<particlesystem>
<type>normal</type>
<!--<offset>
<x-m>1.75098</x-m>
<y-m>-15.5773</y-m>
<z-m>2.10195</z-m>
<pitch-deg>91</pitch-deg>
<heading-deg>0</heading-deg>
<roll-deg>0</roll-deg>
</offset>-->
<name>fluxGD</name>
<attach>world</attach>
<!--<texture>particle1.rgb</texture>--><!-- = the texture path relative to the XML file location-->
<!--particleAlignment BILLBOARD
alignVectorX 1 0 0
alignVectorY 0 1 0-->
<emissive>false</emissive>
<lighting>true</lighting>
<align>billboard</align>
<!--osgParticle::SectorPlacer {
UniqueID SectorPlacer_32
DataVariance DYNAMIC
center 0 0 0
radiusRange 0 0.35
phiRange 0 6.28319
}-->
<placer>
<type>sector</type>
<radius-min-m>0</radius-min-m>
<radius-max-m>0.35</radius-max-m>
<phi-min-deg>0</phi-min-deg>
<phi-max-deg>6.3</phi-max-deg>
<!--<segments> = only for segments, encloses sequential points that form segments
<vertex> = specifies one point, put as many as you want
<x-m>float</x-m>
<y-m>float</y-m>
<z-m>float</z-m>
</vertex>
....
<vertex>
...
</vertex>
</segments>-->
</placer>
<!--osgParticle::RadialShooter {
UniqueID RadialShooter_33
DataVariance DYNAMIC
thetaRange 0 0
phiRange 0 0
initialSpeedRange 4 5
initialRotationalSpeedRange 40 0 0 70 0 0
}-->
<shooter>
<theta-min-deg>0</theta-min-deg>
<theta-max-deg>0</theta-max-deg>
<phi-min-deg>0</phi-min-deg>
<phi-max-deg>0</phi-max-deg>
<speed-mps>
<value>4</value>
<spread>1</spread>
</speed-mps>
<rotation-speed>
<x-min-deg-sec>40</x-min-deg-sec>
<y-min-deg-sec>0</y-min-deg-sec>
<z-min-deg-sec>0</z-min-deg-sec>
<x-max-deg-sec>70</x-max-deg-sec>
<y-max-deg-sec>0</y-max-deg-sec>
<z-max-deg-sec>0</z-max-deg-sec>
</rotation-speed>
</shooter>
<!--osgParticle::RandomRateCounter {
UniqueID RandomRateCounter_31
DataVariance DYNAMIC
rateRange 80 80-->
<counter>
<particles-per-sec>
<value>80</value>
<spread>0</spread>
</particles-per-sec>
<!-- <condition> =a tipical condition that if not true stops particles from being emitted (PPS=0) ....
</condition>-->
</counter>
<!--colorRange 0.440696 0.504509 0.53962 0.8 0.0784009 0.535637 0.540536 1
sizeRange 0.35 0.2-->
<particle>
<start>
<color>
<red>
<value>0.45</value>
</red>
<green>
<value>0.50</value>
</green>
<blue>
<value>0.54</value>
</blue>
<alpha>
<value>0.8</value>
</alpha>
</color>
<size><value>0.35</value></size>
</start>
<end>
<color>
<red>
<value>0.078</value>
</red>
<green>
<value>0.54</value>
</green>
<blue>
<value>0.54</value>
</blue>
<alpha>
<value>1</value>
</alpha>
</color>
<size><value>0.1</value></size>
</end>
<!-- lifeTime 4-->
<life-sec>
<value>4</value>
</life-sec>
<!--radius 0.8
mass 0.8-->
<radius-m>0.8</radius-m>
<mass-kg>0.8</mass-kg>
</particle>
<program>
<fluid>water</fluid>
<gravity>enabled</gravity>
<wind>disabled</wind>
</program>
</particlesystem>
<!--Remarks:
Don't forget you can use existing animations with particles, so if you want to direct or translate the emitter, just use translate, rotate, spin and so on (other animations might have interesting effects too i guess)
Particle XML should be compatible with plib, as the tags will be ignored (you might get some warning if you attach them to animations though)
Try not to use a lot of particles in a way that fills the screen, that will demand lots of fill rate and hurt FPS
If you don't use any properties nor condtions, your particle system doesn't need to use a callback a so it's slightly better on the CPU (mostly useful for static models)
If your particle lifetime is too big you might run out of particles temporarily (still being investigated)
Use mass and size(radius) to adjust the reaction to gravity and wind (mass/size = density)
Altough at the moment severe graphical bugs can be seen in the trails, they are usable. Consider your options correctly! You should consider giving them no initial velocity and most important, no spread, otherwise particles will race and the trail will fold. Start simple (no velocities and forces) and work your way up.-->
</PropertyList>-------------------------------------------------------------------------
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