Linked alpha's - totally not getting it

Scenario:

I have 10 prims linked and 1 script. I'd like 6 of them to go fully invisible on command but the rest to stay visible. I've seen it done and can't figure it out for the life of me.

I know how to do the rest of it, I just can't get the command to go to the right prims with only 1 script.

Advice?

llSetLinkAlpha allows you to specify the link number as does the more complex llSetLinkPrimitiveParams

Thing is, calling those functions you usually have to do one at a time or all at once. Although it is claimed that llSetAlpha() and llSetLinkAlpha() don't have any delay, they do in fact take quite some time to change a set of prims or faces sequentially. Although it is not the nicest setup in the world, if you want to change the visibility of a large set of prims at once you'll really have to broadcast a link message and have scripts in each prim call llSetAlpha() in parallel.

or conversely a set of scripts calling llSetLinkAlpha in parallel, no need to tie it to the individual prims in this case...

The easiest way is to use a script for each prim, otherwise you have to tell your one script which specific prims to make transparent 1-10 which means figuring out what your prims are numbered. They're numbered by link order, last prim linked is 1, next is 2, etc...

Here's an example of the 1 script per prim method. You just drop the script into the prims you want to change to invisible.


default
{
on_rez(integer sides)
{
//sets the prim to opaque on rez
llSetAlpha(0,ALL_SIDES); //change the 0 to 1 for a transparent on rez
}

link_message(integer sender_num, integer num, string str, key id)
{
if (num == 0)
llSetAlpha(0,ALL_SIDES);//receiving the message 0 set's the prim to opaque
else if (num == 1)
llSetAlpha(1,ALL_SIDES);//receiving the message 1 set's the prim to transparent
}
}


Now all you have to do is add
llMessageLinked(-1, 0, "", "";
or
llMessageLinked(-1, 1, "", "";
into your parent script where you want.

You are still really only changing alpha on just 6 prim. All I ever do in a case like that is just a do-while loop, never have noticed any changing before the others with this small anumber of prim:

integer prim = 4;
integer alpha = 0;
default {
	touch_start(integer n) {
		integer a = prim;
		do{
			llSetLinkAlpha(a, alpha, ALL_SIDES);
				a++;
		}while (a < 10);//sets links 4-9
		alpha = !alpha;//switches back and forth between TRUE & FALSE
	}
}

Thanks for all the input folks.

I've got working models of both set up. It's definately a lot more then 10 prims, that was just my scenario to keep the original post nice and concise.

After talking to a few people and seeing both in action on both low (under 100) and high (250+) builds I think I'll be able to put both techniques to use depending on the situation.