llParticleSystem() -- some favorite tricks

(I'm tired of the deathoftheforumdrama threads and felt like posting something different for a change)

Just some random particle script shortcuts I use often:

Setting up a simple "touch" on/off switch, with an auto-off timer.

 default {
 	state_entry() {
 		llParticleSystem( [ 
 				 // (your particle definition here ) 
 			  ] );
 		// llResetTime(); // edited - completely unnecessary, see next posts
 		llSetTimerEvent( 5.0 * 60.0 ); // 5 minute auto-off internval.
 	}
 
 	on_rez(integer n) { llResetScript(); }
 
 	touch_start(integer num_detected) { state particles_off; }
 
 	timer() { state particles_off; }
 	
 	state_exit() { llParticleSystem( [ ] ); } // turns off particles
 }
 
 
 state particles_off {
 	  touch_start( integer num_detected ) { state default; }
 }
 

To automatically use the first texture in the prim's inventory for the particle effect:

  default {
  	state_entry() {
 
 		string texture = "";
 
 		if ( llGetInventoryNumber( INVENTORY_TEXTURE ) > 0 ) 
 			 texture = llGetInventoryName( INVENTORY_TEXTURE, 0 );
  		
 		llParticleSystem( [ 
 				 // (your particle definitions here and... ),
 				  PSYS_SRC_TEXTURE, texture 
 			  ] );
  	}
 
 	changed(integer change_type) {
 		 // start over if prim's inventory changes
 		 if ( change_type & CHANGED_INVENTORY ) { llResetScript(); }
     } 
 }
 

Want a prim to target the parent object it's linked to?
Don't use listens! Try this:

   default {
   	state_entry() {
 		key target = NULL_KEY; 
  		if ( llGetLinkNumber() > 1 ) target = llGetLinkKey( 1 );  
 	 
  		llParticleSystem( [ 
 				 // (your particle definitions here ),
 				 // PSYS_PART_FLAGS, (your flags) 
 						 | PSYS_PART_TARGET_POS_MASK,
  				  PSYS_SRC_TARGET_KEY, target 
  			  ] );
   	}
  
  	changed(integer change_type) {
  		 // start over if the object's links change
  		 if ( change_type & CHANGED_LINK ) { llResetScript(); }
      } 
 
 	on_rez(integer n) { llResetScript(); }
  }
  

If you want to target a child prim of the object (instead of the parent prim), replace the 1 in llGetLinkKey(1) with the # of the child prim. You can get the child prim to tell you it's link number with: llOwnerSay( llGetLinkNumber() );

Just one minor little thing I noticed: llResetTime() has nothing to do with the timer event. All it does is reset the running time of the script for use with llGetTime().

may i add llResetTime / llGetTime / llGetAndResetTime are not things to be using for "mission critical" things

wiki


while true, i think that statement is abit harsh, and it does have its uses (altho not many)

Like detecting when the last time the server was reset perhaps!

Kayla/Osgeld- You're absolutely right: llResetTime() has no impact at all on llSetTimerEvent(). I'd started using it in error when I thought I was seeing event() being called immediately after setting an llSetTimerEvent(n), or called in less than 'n' seconds from being set, and figured llSetTimerEvent() was doing modulus operation on llGetTime(). Oops

Anyway, myth dispelled, thanks for pointing that out!! =)