412 lines
15 KiB
C++
412 lines
15 KiB
C++
#include <osgProducer/Viewer>
|
||
|
||
#include <osg/Group>
|
||
#include <osg/Geode>
|
||
|
||
#include <osgParticle/Particle>
|
||
#include <osgParticle/ParticleSystem>
|
||
#include <osgParticle/ParticleSystemUpdater>
|
||
#include <osgParticle/ModularEmitter>
|
||
#include <osgParticle/ModularProgram>
|
||
#include <osgParticle/RandomRateCounter>
|
||
#include <osgParticle/SectorPlacer>
|
||
#include <osgParticle/RadialShooter>
|
||
#include <osgParticle/AccelOperator>
|
||
#include <osgParticle/FluidFrictionOperator>
|
||
|
||
|
||
|
||
//////////////////////////////////////////////////////////////////////////////
|
||
// CUSTOM OPERATOR CLASS
|
||
//////////////////////////////////////////////////////////////////////////////
|
||
|
||
// This class demonstrates Operator subclassing. This way you can create
|
||
// custom operators to apply your motion effects to the particles. See docs
|
||
// for more details.
|
||
class VortexOperator: public osgParticle::Operator {
|
||
public:
|
||
VortexOperator()
|
||
: osgParticle::Operator(), center_(0, 0, 0), axis_(0, 0, 1), intensity_(0.1f) {}
|
||
|
||
VortexOperator(const VortexOperator ©, const osg::CopyOp ©op = osg::CopyOp::SHALLOW_COPY)
|
||
: osgParticle::Operator(copy, copyop), center_(copy.center_), axis_(copy.axis_), intensity_(copy.intensity_) {}
|
||
|
||
META_Object(osgParticle, VortexOperator);
|
||
|
||
void setCenter(const osg::Vec3 &c)
|
||
{
|
||
center_ = c;
|
||
}
|
||
|
||
void setAxis(const osg::Vec3 &a)
|
||
{
|
||
axis_ = a / a.length();
|
||
}
|
||
|
||
// this method is called by ModularProgram before applying
|
||
// operators on the particle set via the operate() method.
|
||
void beginOperate(osgParticle::Program *prg)
|
||
{
|
||
// we have to check whether the reference frame is relative to parents
|
||
// or it's absolute; in the first case, we must transform the vectors
|
||
// from local to world space.
|
||
if (prg->getReferenceFrame() == osgParticle::Program::RELATIVE_TO_PARENTS) {
|
||
// transform the center point (full transformation)
|
||
xf_center_ = prg->transformLocalToWorld(center_);
|
||
// transform the axis vector (only rotation and scale)
|
||
xf_axis_ = prg->rotateLocalToWorld(axis_);
|
||
} else {
|
||
xf_center_ = center_;
|
||
xf_axis_ = axis_;
|
||
}
|
||
}
|
||
|
||
// apply a vortex-like acceleration. This code is not optimized,
|
||
// it's here only for demonstration purposes.
|
||
void operate(osgParticle::Particle *P, double dt)
|
||
{
|
||
float l = xf_axis_ * (P->getPosition() - xf_center_);
|
||
osg::Vec3 lc = xf_center_ + xf_axis_ * l;
|
||
osg::Vec3 R = P->getPosition() - lc;
|
||
osg::Vec3 v = (R ^ xf_axis_) * P->getMassInv() * intensity_;
|
||
|
||
// compute new position
|
||
osg::Vec3 newpos = P->getPosition() + v * dt;
|
||
|
||
// update the position of the particle without modifying its
|
||
// velocity vector (this is unusual, normally you should call
|
||
// the Particle::setVelocity() or Particle::addVelocity()
|
||
// methods).
|
||
P->setPosition(newpos);
|
||
}
|
||
|
||
protected:
|
||
virtual ~VortexOperator() {}
|
||
|
||
private:
|
||
osg::Vec3 center_;
|
||
osg::Vec3 xf_center_;
|
||
osg::Vec3 axis_;
|
||
osg::Vec3 xf_axis_;
|
||
float intensity_;
|
||
};
|
||
|
||
|
||
//////////////////////////////////////////////////////////////////////////////
|
||
// SIMPLE PARTICLE SYSTEM CREATION
|
||
//////////////////////////////////////////////////////////////////////////////
|
||
|
||
|
||
osgParticle::ParticleSystem *create_simple_particle_system(osg::Group *root)
|
||
{
|
||
|
||
// Ok folks, this is the first particle system we build; it will be
|
||
// very simple, with no textures and no special effects, just default
|
||
// values except for a couple of attributes.
|
||
|
||
// First of all, we create the ParticleSystem object; it will hold
|
||
// our particles and expose the interface for managing them; this object
|
||
// is a Drawable, so we'll have to add it to a Geode later.
|
||
|
||
osgParticle::ParticleSystem *ps = new osgParticle::ParticleSystem;
|
||
|
||
// As for other Drawable classes, the aspect of graphical elements of
|
||
// ParticleSystem (the particles) depends on the StateAttribute's we
|
||
// give it. The ParticleSystem class has an helper function that let
|
||
// us specify a set of the most common attributes: setDefaultAttributes().
|
||
// This method can accept up to three parameters; the first is a texture
|
||
// name (std::string), which can be empty to disable texturing, the second
|
||
// sets whether particles have to be "emissive" (additive blending) or not;
|
||
// the third parameter enables or disables lighting.
|
||
|
||
ps->setDefaultAttributes("", true, false);
|
||
|
||
// Now that our particle system is set we have to create an emitter, that is
|
||
// an object (actually a Node descendant) that generate new particles at
|
||
// each frame. The best choice is to use a ModularEmitter, which allow us to
|
||
// achieve a wide variety of emitting styles by composing the emitter using
|
||
// three objects: a "counter", a "placer" and a "shooter". The counter must
|
||
// tell the ModularEmitter how many particles it has to create for the
|
||
// current frame; then, the ModularEmitter creates these particles, and for
|
||
// each new particle it instructs the placer and the shooter to set its
|
||
// position vector and its velocity vector, respectively.
|
||
// By default, a ModularEmitter object initializes itself with a counter of
|
||
// type RandomRateCounter, a placer of type PointPlacer and a shooter of
|
||
// type RadialShooter (see documentation for details). We are going to leave
|
||
// these default objects there, but we'll modify the counter so that it
|
||
// counts faster (more particles are emitted at each frame).
|
||
|
||
osgParticle::ModularEmitter *emitter = new osgParticle::ModularEmitter;
|
||
|
||
// the first thing you *MUST* do after creating an emitter is to set the
|
||
// destination particle system, otherwise it won't know where to create
|
||
// new particles.
|
||
|
||
emitter->setParticleSystem(ps);
|
||
|
||
// Ok, get a pointer to the emitter's Counter object. We could also
|
||
// create a new RandomRateCounter object and assign it to the emitter,
|
||
// but since the default counter is already a RandomRateCounter, we
|
||
// just get a pointer to it and change a value.
|
||
|
||
osgParticle::RandomRateCounter *rrc =
|
||
static_cast<osgParticle::RandomRateCounter *>(emitter->getCounter());
|
||
|
||
// Now set the rate range to a better value. The actual rate at each frame
|
||
// will be chosen randomly within that range.
|
||
|
||
rrc->setRateRange(20, 30); // generate 20 to 30 particles per second
|
||
|
||
// The emitter is done! Let's add it to the scene graph. The cool thing is
|
||
// that any emitter node will take into account the accumulated local-to-world
|
||
// matrix, so you can attach an emitter to a transform node and see it move.
|
||
|
||
root->addChild(emitter);
|
||
|
||
// Ok folks, we have almost finished. We don't add any particle modifier
|
||
// here (see ModularProgram and Operator classes), so all we still need is
|
||
// to create a Geode and add the particle system to it, so it can be
|
||
// displayed.
|
||
|
||
osg::Geode *geode = new osg::Geode;
|
||
geode->addDrawable(ps);
|
||
|
||
// add the geode to the scene graph
|
||
root->addChild(geode);
|
||
|
||
return ps;
|
||
|
||
}
|
||
|
||
|
||
|
||
//////////////////////////////////////////////////////////////////////////////
|
||
// COMPLEX PARTICLE SYSTEM CREATION
|
||
//////////////////////////////////////////////////////////////////////////////
|
||
|
||
|
||
osgParticle::ParticleSystem *create_complex_particle_system(osg::Group *root)
|
||
{
|
||
// Are you ready for a more complex particle system? Well, read on!
|
||
|
||
// Now we take one step we didn't before: create a particle template.
|
||
// A particle template is simply a Particle object for which you set
|
||
// the desired properties (see documentation for details). When the
|
||
// particle system has to create a new particle and it's been assigned
|
||
// a particle template, the new particle will inherit the template's
|
||
// properties.
|
||
// You can even assign different particle templates to each emitter; in
|
||
// this case, the emitter's template will override the particle system's
|
||
// default template.
|
||
|
||
osgParticle::Particle ptemplate;
|
||
|
||
ptemplate.setLifeTime(3); // 3 seconds of life
|
||
|
||
// the following ranges set the envelope of the respective
|
||
// graphical properties in time.
|
||
ptemplate.setSizeRange(osgParticle::rangef(0.75f, 3.0f));
|
||
ptemplate.setAlphaRange(osgParticle::rangef(0.0f, 1.5f));
|
||
ptemplate.setColorRange(osgParticle::rangev4(
|
||
osg::Vec4(1, 0.5f, 0.3f, 1.5f),
|
||
osg::Vec4(0, 0.7f, 1.0f, 0.0f)));
|
||
|
||
// these are physical properties of the particle
|
||
ptemplate.setRadius(0.05f); // 5 cm wide particles
|
||
ptemplate.setMass(0.05f); // 50 g heavy
|
||
|
||
// As usual, let's create the ParticleSystem object and set its
|
||
// default state attributes. This time we use a texture named
|
||
// "smoke.rgb", you can find it in the data distribution of OSG.
|
||
// We turn off the additive blending, because smoke has no self-
|
||
// illumination.
|
||
osgParticle::ParticleSystem *ps = new osgParticle::ParticleSystem;
|
||
ps->setDefaultAttributes("Images/smoke.rgb", false, false);
|
||
|
||
// assign the particle template to the system.
|
||
ps->setDefaultParticleTemplate(ptemplate);
|
||
|
||
// now we have to create an emitter; this will be a ModularEmitter, for which
|
||
// we define a RandomRateCounter as counter, a SectorPlacer as placer, and
|
||
// a RadialShooter as shooter.
|
||
osgParticle::ModularEmitter *emitter = new osgParticle::ModularEmitter;
|
||
emitter->setParticleSystem(ps);
|
||
|
||
// setup the counter
|
||
osgParticle::RandomRateCounter *counter = new osgParticle::RandomRateCounter;
|
||
counter->setRateRange(60, 60);
|
||
emitter->setCounter(counter);
|
||
|
||
// setup the placer; it will be a circle of radius 5 (the particles will
|
||
// be placed inside this circle).
|
||
osgParticle::SectorPlacer *placer = new osgParticle::SectorPlacer;
|
||
placer->setCenter(8, 0, 10);
|
||
placer->setRadiusRange(2.5, 5);
|
||
placer->setPhiRange(0, 2 * osg::PI); // 360<36> angle to make a circle
|
||
emitter->setPlacer(placer);
|
||
|
||
// now let's setup the shooter; we use a RadialShooter but we set the
|
||
// initial speed to zero, because we want the particles to fall down
|
||
// only under the effect of the gravity force. Since we se the speed
|
||
// to zero, there is no need to setup the shooting angles.
|
||
osgParticle::RadialShooter *shooter = new osgParticle::RadialShooter;
|
||
shooter->setInitialSpeedRange(0, 0);
|
||
emitter->setShooter(shooter);
|
||
|
||
// add the emitter to the scene graph
|
||
root->addChild(emitter);
|
||
|
||
// WELL, we got our particle system and a nice emitter. Now we want to
|
||
// simulate the effect of the earth gravity, so first of all we have to
|
||
// create a Program. It is a particle processor just like the Emitter
|
||
// class, but it allows to modify particle properties *after* they have
|
||
// been created.
|
||
// The ModularProgram class can be thought as a sequence of operators,
|
||
// each one performing some actions on the particles. So, the trick is:
|
||
// create the ModularProgram object, create one or more Operator objects,
|
||
// add those operators to the ModularProgram, and finally add the
|
||
// ModularProgram object to the scene graph.
|
||
// NOTE: since the Program objects perform actions after the particles
|
||
// have been emitted by one or more Emitter objects, all instances of
|
||
// Program (and its descendants) should be placed *after* the instances
|
||
// of Emitter objects in the scene graph.
|
||
|
||
osgParticle::ModularProgram *program = new osgParticle::ModularProgram;
|
||
program->setParticleSystem(ps);
|
||
|
||
// create an operator that simulates the gravity acceleration.
|
||
osgParticle::AccelOperator *op1 = new osgParticle::AccelOperator;
|
||
op1->setToGravity();
|
||
program->addOperator(op1);
|
||
|
||
// now create a custom operator, we have defined it before (see
|
||
// class VortexOperator).
|
||
VortexOperator *op2 = new VortexOperator;
|
||
op2->setCenter(osg::Vec3(8, 0, 0));
|
||
program->addOperator(op2);
|
||
|
||
// let's add a fluid operator to simulate air friction.
|
||
osgParticle::FluidFrictionOperator *op3 = new osgParticle::FluidFrictionOperator;
|
||
op3->setFluidToAir();
|
||
program->addOperator(op3);
|
||
|
||
// add the program to the scene graph
|
||
root->addChild(program);
|
||
|
||
// create a Geode to contain our particle system.
|
||
osg::Geode *geode = new osg::Geode;
|
||
geode->addDrawable(ps);
|
||
|
||
// add the geode to the scene graph.
|
||
root->addChild(geode);
|
||
|
||
return ps;
|
||
}
|
||
|
||
|
||
//////////////////////////////////////////////////////////////////////////////
|
||
// MAIN SCENE GRAPH BUILDING FUNCTION
|
||
//////////////////////////////////////////////////////////////////////////////
|
||
|
||
|
||
void build_world(osg::Group *root)
|
||
{
|
||
|
||
// In this function we are going to create two particle systems;
|
||
// the first one will be very simple, based mostly on default properties;
|
||
// the second one will be a little bit more complex, showing how to
|
||
// create custom operators.
|
||
// To avoid inserting too much code in a single function, we have
|
||
// splitted the work into two functions which accept a Group node as
|
||
// parameter, and return a pointer to the particle system they created.
|
||
|
||
osgParticle::ParticleSystem *ps1 = create_simple_particle_system(root);
|
||
osgParticle::ParticleSystem *ps2 = create_complex_particle_system(root);
|
||
|
||
// Now that the particle systems and all other related objects have been
|
||
// created, we have to add an "updater" node to the scene graph. This node
|
||
// will react to cull traversal by updating the specified particles system.
|
||
|
||
osgParticle::ParticleSystemUpdater *psu = new osgParticle::ParticleSystemUpdater;
|
||
psu->addParticleSystem(ps1);
|
||
psu->addParticleSystem(ps2);
|
||
|
||
// add the updater node to the scene graph
|
||
root->addChild(psu);
|
||
|
||
}
|
||
|
||
|
||
//////////////////////////////////////////////////////////////////////////////
|
||
// main()
|
||
//////////////////////////////////////////////////////////////////////////////
|
||
|
||
|
||
int main(int argc, char **argv)
|
||
{
|
||
// use an ArgumentParser object to manage the program arguments.
|
||
osg::ArgumentParser arguments(&argc,argv);
|
||
|
||
// set up the usage document, in case we need to print out how to use this program.
|
||
arguments.getApplicationUsage()->setDescription(arguments.getApplicationName()+" is the example which demonstrates use of particle systems.");
|
||
arguments.getApplicationUsage()->setCommandLineUsage(arguments.getApplicationName()+" [options] image_file_left_eye image_file_right_eye");
|
||
arguments.getApplicationUsage()->addCommandLineOption("-h or --help","Display this information");
|
||
|
||
|
||
// construct the viewer.
|
||
osgProducer::Viewer viewer(arguments);
|
||
|
||
// set up the value with sensible default event handlers.
|
||
viewer.setUpViewer(osgProducer::Viewer::STANDARD_SETTINGS);
|
||
|
||
// get details on keyboard and mouse bindings used by the viewer.
|
||
viewer.getUsage(*arguments.getApplicationUsage());
|
||
|
||
// if user request help write it out to cout.
|
||
if (arguments.read("-h") || arguments.read("--help"))
|
||
{
|
||
arguments.getApplicationUsage()->write(std::cout);
|
||
return 1;
|
||
}
|
||
|
||
// any option left unread are converted into errors to write out later.
|
||
arguments.reportRemainingOptionsAsUnrecognized();
|
||
|
||
// report any errors if they have occured when parsing the program aguments.
|
||
if (arguments.errors())
|
||
{
|
||
arguments.writeErrorMessages(std::cout);
|
||
return 1;
|
||
}
|
||
|
||
osg::Group *root = new osg::Group;
|
||
build_world(root);
|
||
|
||
// add a viewport to the viewer and attach the scene graph.
|
||
viewer.setSceneData(root);
|
||
|
||
// create the windows and run the threads.
|
||
// viewer.realize();
|
||
// run single threaded since osgParticle still writes during cull.
|
||
viewer.realize(Producer::CameraGroup::SingleThreaded);
|
||
|
||
while( !viewer.done() )
|
||
{
|
||
// wait for all cull and draw threads to complete.
|
||
viewer.sync();
|
||
|
||
// update the scene by traversing it with the the update visitor which will
|
||
// call all node update callbacks and animations.
|
||
viewer.update();
|
||
|
||
// fire off the cull and draw traversals of the scene.
|
||
viewer.frame();
|
||
|
||
}
|
||
|
||
// wait for all cull and draw threads to complete before exit.
|
||
viewer.sync();
|
||
|
||
return 0;
|
||
}
|