cocos2d for iPhone

A fast, easy to use, free, and community supported 2D game engine

1. 

   Osiris
   Member

   I'm digging through the examples of particle effects. Are there any "best practices" or documentation that tells me what the varioous parameters do or how they affect the over all particle shower?

   I have the following:

   ParticleSystem* emitter = [[ParticleSun alloc] initWithTotalParticles:500];
   	[self addChild: emitter z:10];
   	[emitter release];
   
   	emitter.texture = [[TextureMgr sharedTextureMgr] addImage: @"stars.png"];
   	//emitter.texture = particle;
   	emitter.startSize = 10;
   	emitter.duration = 1;
   	emitter.lifeVar = 0;
   	emitter.life = 1;
   	emitter.speed = 100;
   	emitter.speedVar = 0;
   	emitter.emissionRate = 5000;
   	emitter.position = myPoint;

   my problem is that even though I chose "1" for duration, the entire EFX last at least 5 seconds? I'm also trying to discern the relationship between "emissionRate of 5000" and the "initWithTotalParticles" of 500?

   Posted 2 years ago #
2. 

   ob1
   Member

   I am not a "pro" of particles, but I would think that duration is the time lapse during which the emitter will emit particles, and life is the lifetime of each particle.

   So in your exemple, your effect will last at least two seconds.

   Emission rate is well the speed at which particles are emitted and toal particles is the maximum number of particles on screen. In effet, if your emission rate is faster than the decay or your particles, then as some point your emitter will stop emitting particles until some particles "die".

   I hope I am clear.

   Posted 2 years ago #
3. 

   abitofcode
   Moderator

   I found using Pvrtc rather than Png gave me a bit of an increase on my frame rate, it hit the quality of the graphics (especially line art) but I managed to reduce the artifacts on the texture by using a bigger texture 128x128 and then scaling its start and end size. This kept the artifacts small as well. The particles were quite big (think zombieville zombie pieces)

   I should really run some comparisons between the two to determine whether the change is worth it.

   Posted 2 years ago #
4. 

   abitofcode
   Moderator

   BTW: have you tried the particle view Example in the latest cocos2d distribution v0.8.1 it has a GUI that allows you to change all the particle properties as well as combine a number of particle systems.

   Posted 2 years ago #
5. 

   Osiris
   Member

   @ob1 - ok, I thought that duration and life should overlap. I was interpreting to be the EFX in general would be 1 sec long and during that time, the life of the particle would also be 1 sec.

   Thanks for the input!

   Posted 2 years ago #
6. 

   Steve Oldmeadow
   Administrator

   In the code for the particle classes there are links to online articles that Riq has based the algorithms on.

   Posted 2 years ago #
7. 

   Mur3ik
   Member

   I'm digging through the examples of particle effects. Are there any "best practices" or documentation that tells me what the varioous parameters do or how they affect the over all particle shower?

   you could use Particle Mint to find out how parameters of particle system affect to performance.

   Posted 10 months ago #
8. 

   cocos
   Member

   @Mur3ik Does Particle Mint show frame rate? How performance can be assessed?

   Posted 10 months ago #
9. 

   Mur3ik
   Member

   No, it doesn't show fps, but I requested this future. As they said - It will come with next update.

   Posted 10 months ago #

RSS feed for this topic

Reply

You must log in to post.