particle emitters

pin3 · Post by **pin3** » Sun Aug 09, 2009 6:17 pm

The tutorial doesn`t explain too well the emitter params. Is there a method I can set the speed at which the particles come out?

Seven · Post by **Seven** » Sun Aug 09, 2009 6:29 pm

direction is also speed

pin3 · Post by **pin3** » Mon Aug 10, 2009 12:42 pm

thanks, that works

pin3 · Post by **pin3** » Tue Aug 11, 2009 7:47 am

Is there a way to set two emitters per particle system, or two materials per particle system. I.e I want to imitate fire and smoke and I need a texture for each. I dont want to use two ps per each fire.

Also how do you get smoke, the fire is a yellow texture fading into black. If I want black smoke what texture do I use

(I tried to use a png with EMT_TRANSPARENT_ALPHA_CHANEL but it doesnt work almost at all)

VPB_Enge · Post by **VPB_Enge** » Fri Aug 14, 2009 9:46 pm

copy/paste from one of my routines:
FireNode.SmokePlums.PlumColor=90;
FireNode.SmokePlums.SmokePlum->setColor(video::SColor(255,FireNode.SmokePlums.PlumColor,
FireNode.SmokePlums.PlumColor,FireNode.SmokePlums.PlumColor));
FireNode.SmokePlums.SmokePlum->setMaterialFlag(video::EMF_LIGHTING, false);
FireNode.SmokePlums.SmokePlum->setMaterialFlag(video::EMF_ZWRITE_ENABLE, false);
FireNode.SmokePlums.SmokePlum->setMaterialTexture(0, driver->getTexture("../../media/smoke.tga"));
FireNode.SmokePlums.SmokePlum->setMaterialType(video::EMT_TRANSPARENT_ALPHA_CHANNEL);

The tga file has a transparency mask. (masking the surrounding of the plum)
The trick is the smokecolor, the lower, the darker.
Use the fireball example in media and make it gray or something.

pin3 · Post by **pin3** » Wed Aug 19, 2009 7:44 am

I'm not going to discuss too much about the code design but it seems that there are redundant calls at times (i.e. when creating particles), making things needlessly complicated

scene::IParticleEmitter* em2 = ps2->createBoxEmitter(...);
ps2->setEmitter(em2); // this grabs the emitter

scene::IParticleAffector* paf2 = ps2->createFadeOutParticleAffector(video::SColor(0,255,255,255));
ps2->addAffector(paf2); // same goes for the affector
why does one need setEmitter() and addAffector()?

hybrid · Post by **hybrid** » Wed Aug 19, 2009 9:23 am

Simply because you need an emitter and you may use affectors. We could also add an emitter via a type parameter in the constructor of the particle system, but that wouldn't allow for different parameters for the emitters. So most people would need to access the emitter afterwards and change the settings. Makes the code just as complicated.

pin3 · Post by **pin3** » Thu Aug 20, 2009 5:44 am

Well if you create a scene node with addSceneNode() you dont then later call SceneManager->setNode().

hybrid · Post by **hybrid** » Thu Aug 20, 2009 8:44 am

The emitter is *not* the particle system. It's just the way the particles are emitted. And since this special part of the particle system is highly configurable and can be replaced by many different implementations, it's used as is.

pin3 · Post by **pin3** » Wed Aug 26, 2009 11:24 am

The emitter is *not* the particle system.
Neither is the node the scene manager.
Can you set as emitter something else then an IParticleEmitter ?
Its a faulty line of thinking IMO.

Anyways I`m using Irrlicht as it is and I have another question.
Is there a way to control the particle billboard rotation? I want the particles to come out as lines perpedicular to the emitter, however they come out horizontaly to the user no matter at which angle the ps is.

Dark_Kilauea · Post by **Dark_Kilauea** » Wed Aug 26, 2009 10:15 pm

on the emitter point, if you wanted to, you could code your own particle emitter in your application in order to get a particle system to emit particles however you want it to. Thus, why things are set up the way they are.

As for the orientation of the particles, you will have to edit the particle system node in order to support locking the billboards into a certain orientation.