Hi, I have question about osg.
I make particls as it made it examples, then use MatrixTransform, then attach
emitter to
MatrixTransform ( MyMatrixTrans->addChild(emitter); ). After that I add
MatrixTransform to
scene group ( root->addChild(MyMatrixTrans); ). But when I move/rotate
MyMatrixTrans,
particles moves incorrect (position of MyMatrixTrans and emitter doesn't match).
In the Internet I found this:
Particle system looks strange when I position them in my scene
You are probably rotating both the particle systems and the particle emitters.
The tranform above the particle system(s) should match your world's (absolute)
coordinate frame, or the reference frame that "contains" the particles (for
example, an airplane or a car).
To transform a particle system inside this reference frame you should transform
only the emitters, not the ParticleSystem drawables. If you apply a transform
above "fountain.osg" you actually apply a translation/rotation to both emitters
and particle systems;
To get a correct behavior you should traverse the scene graph and avoid
applying the transform to any geodes containing ParticleSystem drawables
How can I do this in practice?
[code]
class BaseParticle
{
public:
osgParticle::Particle *ptemplate;
osgParticle::ParticleSystem *ps;
osgParticle::ModularEmitter *emitter;
osgParticle::RandomRateCounter *rrc;
osgParticle::ParticleSystemUpdater *psu;
//созданные обертки (для возможности работать с текстом командами типа
RSetPosition..)
osg::MatrixTransform* particleMatrix;
};
bool InterfaceForParticle::AddParticle(std::string Name)
{
//+проверка на совпадение имен с уже имеющимися
if (particles.count(Name)!=0)
{
std::cout << "Warning: Particle '" << Name << "' already exsist!" << std::endl;
return false;
}
particles[Name] = new BaseParticle;
particles[Name]->particleMatrix = new osg::MatrixTransform();
particles[Name]->particleMatrix->setName (Name);
particles[Name]->ptemplate = new osgParticle::Particle;
particles[Name]->ptemplate->setLifeTime(3); // 3 seconds of life
particles[Name]->ptemplate->setSizeRange(osgParticle::rangef(0.75f, 3.0f));
particles[Name]->ptemplate->setAlphaRange(osgParticle::rangef(0.0f, 1.5f));
particles[Name]->ptemplate->setColorRange(osgParticle::rangev4(
osg::Vec4(1, 0.5f, 0.3f, 1.5f),
osg::Vec4(0, 0.0f, 0.0f, 0.0f)));
// these are physical properties of the particle
particles[Name]->ptemplate->setRadius(0.05f); // 5 cm wide particles
particles[Name]->ptemplate->setMass(0.05f); // 50 g heavy
//FONTAN->setPosition (osg::Vec3(10, 10, 10));
//particles[Name]->ptemplate->setAngle (osg::Vec3(1,1,1));
particles[Name]->ps = new osgParticle::ParticleSystem;
//particles[Name]->ps->setDefaultAttributes("", true, false);
particles[Name]->ps->setDefaultAttributes("", false,
false);//D:/DEVELOP/OSG/OpenSceneGraph-2.6.0/bin/Images/smoke.rgb
// assign the particle template to the system.
particles[Name]->ps->setDefaultParticleTemplate(*particles[Name]->ptemplate);
particles[Name]->emitter = new osgParticle::ModularEmitter;
particles[Name]->emitter->setParticleSystem(particles[Name]->ps);
particles[Name]->rrc = static_cast<osgParticle::RandomRateCounter
*>(particles[Name]->emitter->getCounter());
particles[Name]->rrc->setRateRange(20, 30); // generate 20 to 30 particles per
second
particles[Name]->particleMatrix->addChild(particles[Name]->emitter);
osg::Geode *geode = new osg::Geode;
geode->addDrawable(particles[Name]->ps);
particles[Name]->particleMatrix->addChild(geode);
particles[Name]->psu = new osgParticle::ParticleSystemUpdater;
particles[Name]->psu->addParticleSystem(particles[Name]->ps);
particles[Name]->particleMatrix->addChild(particles[Name]->psu);
root->addChild(particles[Name]->particleMatrix);
return true;
}
[/code]
osg 2.6.x, 2.7.x; MSVS2009
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