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conor
Member
Hey vutronic,
Thanks, that makes sense.
I've been trying to use a particle system for a flame tower in my game. It's starting to look like a no go as having more then 10 particle systems drops the frame rate immensely and I can't seem to get a single particle system emitting at multiple locations to work quite right. I think i'll just go with sprite animations and leave the particle system for explosions.
Conor: With my method you can spawn at multiple positions at the same time. I do not know why it freeses. Remember to set the emittionRate to 0 and spwan particles only with the spqn method I posted in this thread.
I really would use particles systems for a flame thrower! remember to use pvr images for all particles sytems to keep a good framerate!
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conor
Member
@zombie: Thanks for taking the time. It seems like I have everything set up as you described, emission rate set to 0 and the spawn method. However when i comment out the code you mentioned it seems to get stuck in an infinite loop. Without commenting things out it seems to act a bit haywire.
Just to confirm, are you using the v0.8 beta or rc?
As you say, it would be awesome to use the particle system for my flame throwers. Do you think it's realistic to have 20+ flame throwers all emitting particles continuously at the same time??? If so that would be huge! Just need to get it to work :)
Conor:
Try to debug and find the cause for this crash. It can be that I missed a change I made to post here, as I have changed many things of the particle systems.
I am always working on the trunc. (As long as we go into the final production stage)
You can have up to 2000 particles the same time without any fps loss (so 60fps) , the number of emitters is not really the limiting factor. As long as this it not getting toooo huge.
It also depends on the size of the particles, the bigger the lower the performance. 2000 is for smaller particles (size around 10).
This is not founded on scientific tests, I just played around a bit :)
Let me know where excacly it is crashing.
Zombie - follow me on Twitter for some shocking news soons: http://twitter.com/ZombieSmash
conor
Member
It was crashing because i hadn't commented out the top of the if statement "if( p->life > 0 ) {".
Ok, so i almost have this working.... "almost". I'm getting a very frustrating flicker going on with the particles. I have a grid of constantly emitting positions. I set up a timer to fire off a spawn at each of the positions so i get a steady stream of particles at each point. The problem i'm getting is that the particles randomly glitch and show up in random spots away from the emission points i'm setting. I've been over my code ad nauseum looking for something odd i could be doing but i can't find anything. I'm thinking it something with the life of the particles.
I have a test project. if anyone wants to take a look. It's very odd. I would love to get this to work. Seems like others would benefit from this functionality.
Here is my particle class.
@implementation FireEmitter
-(id) init
{
particlePos = 0;
return [self initWithTotalParticles:200];
}
-(id) initWithTotalParticles:(int) p
{
if( !(self=[super initWithTotalParticles:p]) )
return nil;
// duration
duration = -1;
// gravity
gravity.x = 0;
gravity.y = 0;
// angle
angle = 90;
angleVar = 5;
// radial acceleration
radialAccel = 0;
radialAccelVar = 0;
// emitter position
//self.position = ccp(-1000, -1000);
posVar = CGPointZero;
// life of particles
life = 1.0f;
lifeVar = 0.5f;
// speed of particles
speed = 50;
speedVar = 50;
// size, in pixels
startSize = 5.0f;
startSizeVar = 4.0f;
//endSize = kParticleStartSizeEqualToEndSize;
// emits per frame
//emissionRate = totalParticles/life;
emissionRate = 0;
// color of particles
startColor.r = 0.76f;
startColor.g = 0.25f;
startColor.b = 0.12f;
startColor.a = 1.0f;
startColorVar.r = 0.0f;
startColorVar.g = 0.0f;
startColorVar.b = 0.0f;
startColorVar.a = 0.0f;
endColor.r = 0.0f;
endColor.g = 0.0f;
endColor.b = 0.0f;
endColor.a = 1.0f;
endColorVar.r = 0.0f;
endColorVar.g = 0.0f;
endColorVar.b = 0.0f;
endColorVar.a = 0.0f;
self.texture = [[TextureMgr sharedTextureMgr] addImage: @"fire.pvr"];
// additive
blendAdditive = YES;
return self;
}
// do not mix spawn with addParticle (so also not with self emitting systems)
- (void) spawnParticles:(uint)n
{
Particle* particle;
for(uint i=0; i<n; i++)
{
particle = &particles[ particlePos ];
[self initParticle: particle];
particlePos++;
particleCount++;
if(particlePos==totalParticles)
{
particlePos=0;
}
if(particleCount>totalParticles)
{
particleCount=totalParticles;
}
}
}
@endwhich is triggered something like this on a tick
for(FireNode* node in children){
if ([node isKindOfClass:[FireNode class]]) {
[node fire];
}
}
-(void)fire{
if(shouldEmitFire){
[fireEmitter setPosition:[self position]];
[fireEmitter spawnParticles:100];
}
}Hi,
I use setCenterOfGravity instaed of setPosition. Do you have set the system to positionType_=kPositionTypeFree?
One problem that you will have with my method is that the newer particles are not always in front of older ones.
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rx82
Member
@conor
After taking a quick look at your code, I noticed you're calling "[fireEmitter setPosition:[self position]];" ... how is this setting a unique position for your spawned particles??? Doesn't this just randomly emit particles relative to the emitter's position? It seems you need to be setting the position of the spawned particles themselves, not the emitter...
@zombie
how is your method accurately setting the position of the newly formed particle?
conor
Member
@zombie. You are a gentleman and a scholar. setCenterOfGravity did the trick. No more flicker.
@rx82 The code i posted may have been a bit misleading. The fire method is in a cocosnode (atlassprite). In my main game tick i loop through all my flame nodes and call the fire which sets the position of the emitter to the position of the node being fired.
vutronic
Member
@Conor are you able to run multiple explosions at different positions with one emitter?
I commented out these lines but it doesn't seem to work for me:
//if( p->life > 0 ) {
......
// } else {
// life < 0
// if( particleIdx != particleCount-1 )
// particles[particleIdx] = particles[particleCount-1];
// particleCount--;
// if( particleCount == 0 && autoRemoveOnFinish_ ) {
// [self unschedule:@selector(step:)];
// [[self parent] removeChild:self cleanup:YES];
// }
//}
@Conor: Great that this works for you. It was my pleasure to help you. Now let them burn... ;)
@vutronic: Yes this is possible. Read the whole thread. Commenting out the code lines is only one step. You have to use my spawn method and set the center of gravity before each spawn.
Zombie - follow me on Twitter for some shocking news soon: http://twitter.com/ZombieSmash
Nice Conor. Look like a Tower Defence Game.
Maybe add some smoke behind the fire, that lasts a bit longer and has a negative gravity so it will move upwards.
Good luck with your game.
Zombie - follow me on Twitter for some shocking news soon: http://twitter.com/ZombieSmash
conor
Member
thanks zombie. Yes it's a TD game, and a labor of love ;)
I was thinking of having another particle system for smoke that emits when a creep actually gets hit. Should make it look like the creeps are smoldering a bit as they pass through.
I'm wondering if it would be possible to create an electricity effect with a particle system? I was thinking I might be able to create some sort of random path to the target and emitting sparks along the path. Not sure if a particle system is really the right approach or not.
If you find a good way for a electricity effect, let me know.
Zombie - follow me on Twitter for some shocking news soon: http://twitter.com/ZombieSmash
Zombie, Conor - thx for your work. It has helped me a lot.
I've been trying to add a trail-effect - and while it is ALMOST there - theres some funny flickr (and i have been trying to change centeroofgravity instead of position - but that just placed stuff all the wrong places). Do you have any ideas for a good trail-ing of elements in motion?
I do trailing with a scheduled function calling setCenterOfGravity and spawn every frame (or whatever time interval.
Can you upload a video showing the problem?
Zombie - follow me on Twitter for some shocking news soon: http://twitter.com/ZombieSmash
conor
Member
@popgoblin I was having the exact same problem, i had a setPosition in my code that was throwing everything off. Glad you sorted it out!
Has anyone noticed any "leakage" with this method. I'm getting a small emission of particles at 240,160 (middle of screen) where a few particles leak before emitting from the correct location.
Conor: Is that the default position the particle system is initilized with? Perhaps you call the spawn before the setCenterOfGravity. Or there is something wrong with the setCenterOfgravity.
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I have been trying this for over a week now, and must be missing something.
Most of the time, I have been experimenting with what code to comment out in the cocos code, without much luck.
Anyone know exactly what lines need to be commented out? From this thread there are at least 3 possibilities.
vutronic
Member
Thorox..here is the whole modified class. I commented out some lines in the steps method. Good luck. Works great for me.
/* cocos2d for iPhone
*
* http://www.cocos2d-iphone.org
*
* Copyright (C) 2008,2009 Ricardo Quesada
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the 'cocos2d for iPhone' license.
*
* You will find a copy of this license within the cocos2d for iPhone
* distribution inside the "LICENSE" file.
*
*/
// opengl
#import <OpenGLES/ES1/gl.h>
// cocos2d
#import "PointParticleSystem.h"
#import "TextureMgr.h"
#import "ccMacros.h"
// support
#import "Support/OpenGL_Internal.h"
#import "Support/CGPointExtension.h"
@implementation PointParticleSystem
-(id) initWithTotalParticles:(int) numberOfParticles
{
if( (self=[super initWithTotalParticles:numberOfParticles]) ) {
vertices = malloc( sizeof(ccPointSprite) * totalParticles );
if( ! vertices ) {
NSLog(@"Particle system: not enough memory");
if( vertices )
free(vertices);
return nil;
}
glGenBuffers(1, &verticesID);
// initial binding
glBindBuffer(GL_ARRAY_BUFFER, verticesID);
glBufferData(GL_ARRAY_BUFFER, sizeof(ccPointSprite)*totalParticles, vertices,GL_DYNAMIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);
}
return self;
}
-(void) dealloc
{
free(vertices);
glDeleteBuffers(1, &verticesID);
[super dealloc];
}
// XXX
// XXX: All subclasses of ParticleSystem share this code
// XXX: so some parts of this coded should be moved to the base class
// XXX
// XXX: BUT the change shall NOT DROP a single FPS
// XXX:
-(void) step: (ccTime) dt
{
if( active && emissionRate ) {
float rate = 1.0f / emissionRate;
emitCounter += dt;
while( particleCount < totalParticles && emitCounter > rate ) {
[self addParticle];
emitCounter -= rate;
}
elapsed += dt;
if(duration != -1 && duration < elapsed)
[self stopSystem];
}
particleIdx = 0;
// test performance with [self absolutePosition];
// CGPoint absolutePosition = [self convertToWorldSpace:CGPointZero];
CGPoint absolutePosition = position_;
while( particleIdx < particleCount )
{
Particle *p = &particles[particleIdx];
// if( p->life > 0 ) {
CGPoint tmp, radial, tangential;
radial = CGPointZero;
// radial acceleration
if(p->pos.x || p->pos.y)
radial = ccpNormalize(p->pos);
tangential = radial;
radial = ccpMult(radial, p->radialAccel);
// tangential acceleration
float newy = tangential.x;
tangential.x = -tangential.y;
tangential.y = newy;
tangential = ccpMult(tangential, p->tangentialAccel);
// (gravity + radial + tangential) * dt
tmp = ccpAdd( ccpAdd( radial, tangential), gravity);
tmp = ccpMult( tmp, dt);
p->dir = ccpAdd( p->dir, tmp);
tmp = ccpMult(p->dir, dt);
p->pos = ccpAdd( p->pos, tmp );
p->color.r += (p->deltaColor.r * dt);
p->color.g += (p->deltaColor.g * dt);
p->color.b += (p->deltaColor.b * dt);
p->color.a += (p->deltaColor.a * dt);
p->size += (p->deltaSize * dt);
p->size = MAX( 0, p->size );
p->life -= dt;
//
// update values in point
//
CGPoint newPos = p->pos;
if( positionType_ == kPositionTypeFree ) {
newPos = ccpSub(absolutePosition, p->startPos);
newPos = ccpSub( p->pos, newPos);
}
// place vertices and colos in array
vertices[particleIdx].pos = newPos;
vertices[particleIdx].size = p->size;
vertices[particleIdx].colors = p->color;
// update particle counter
particleIdx++;
/* } else {
// life < 0
if( particleIdx != particleCount-1 )
particles[particleIdx] = particles[particleCount-1];
particleCount--;
if( particleCount == 0 && autoRemoveOnFinish_ ) {
[self unschedule:@selector(step:)];
[[self parent] removeChild:self cleanup:YES];
}
}*/
}
glBindBuffer(GL_ARRAY_BUFFER, verticesID);
glBufferData(GL_ARRAY_BUFFER, sizeof(ccPointSprite)*particleCount, vertices,GL_DYNAMIC_DRAW);
glBindBuffer(GL_ARRAY_BUFFER, 0);
}
-(void) draw
{
// int blendSrc, blendDst;
// int colorMode;
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, texture_.name);
glEnable(GL_POINT_SPRITE_OES);
glTexEnvi( GL_POINT_SPRITE_OES, GL_COORD_REPLACE_OES, GL_TRUE );
glBindBuffer(GL_ARRAY_BUFFER, verticesID);
glEnableClientState(GL_VERTEX_ARRAY);
glVertexPointer(2,GL_FLOAT,sizeof(vertices[0]),0);
glEnableClientState(GL_COLOR_ARRAY);
glColorPointer(4, GL_FLOAT, sizeof(vertices[0]),(GLvoid*) offsetof(ccPointSprite,colors) );
glEnableClientState(GL_POINT_SIZE_ARRAY_OES);
glPointSizePointerOES(GL_FLOAT,sizeof(vertices[0]),(GLvoid*) offsetof(ccPointSprite,size) );
BOOL newBlend = NO;
if( blendAdditive )
glBlendFunc(GL_SRC_ALPHA, GL_ONE);
else if( blendFunc_.src != CC_BLEND_SRC || blendFunc_.dst != CC_BLEND_DST ) {
newBlend = YES;
glBlendFunc( blendFunc_.src, blendFunc_.dst );
}
// save color mode
#if 0
glGetTexEnviv(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, &colorMode);
if( colorModulate )
glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE );
else
glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE );
#endif
glDrawArrays(GL_POINTS, 0, particleIdx);
// restore blend state
if( blendAdditive || newBlend )
glBlendFunc( CC_BLEND_SRC, CC_BLEND_DST);
#if 0
// restore color mode
glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, colorMode);
#endif
// unbind VBO buffer
glBindBuffer(GL_ARRAY_BUFFER, 0);
glDisableClientState(GL_POINT_SIZE_ARRAY_OES);
glDisableClientState(GL_COLOR_ARRAY);
glDisableClientState(GL_VERTEX_ARRAY);
glDisable(GL_TEXTURE_2D);
glDisable(GL_POINT_SPRITE_OES);
}
#pragma mark Non supported properties
//
// SPIN IS NOT SUPPORTED
//
-(void) setStartSpin:(float)a
{
NSAssert(a == 0, @"PointParticleSystem doesn't support spinning");
[super setStartSpin:a];
}
-(void) setStartSpinVar:(float)a
{
NSAssert(a == 0, @"PointParticleSystem doesn't support spinning");
[super setStartSpin:a];
}
-(void) setEndSpin:(float)a
{
NSAssert(a == 0, @"PointParticleSystem doesn't support spinning");
[super setStartSpin:a];
}
-(void) setEndSpinVar:(float)a
{
NSAssert(a == 0, @"PointParticleSystem doesn't support spinning");
[super setStartSpin:a];
}
//
// SIZE > 64 IS NOT SUPPORTED
//
-(void) setStartSize:(float)size
{
NSAssert(size <= 64, @"PointParticleSystem doesn't support size > 64");
[super setStartSize:size];
}
@end
vutronic
Member
@Codemattic nice so that's backticks. I had no idea what it was.
To everybody using my managed particle system code:
You should know that with my old implementation, there is a bigger performance problem for some usage cases: It will always iterate over ALL particles, even the died out ones. It will not draw them, but look at them, which will be bad when you have several thousands of them.
- zombie
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