Flapping Flexi Butterfly (insect) Wings - Big Secret?

heyas;

you know those avatar wings, usually butterfly wings, that are alpha textures on a flexi prim, that flap? is the key to flapping these things a huge trade secret, or can someone give me some kinda HINT over here?

i have tried the most obvious solutions and learned some things.


1: despite the fact that flex prims have their editing center moved to an endpoint, they still rotate and targetomega from their real center.


2: although you can change a flex prim to a sphere, dimple it to .5, and thence turn it back into a 'chopped in half' prim (whose center appears to be at its endpoint!), the flex gets turned off during this maneuver, and turning it back on erases the inherited dimple.


3: you can't attach two separate wings (with, say, root spheres that define the center of rotation for the whole object) to one avatar hardpoint.


4: llsetrot and llsetlocal rot jerk the thing around anyway, even if it did rotate from the point i wanted it to rotate from.

think of what happens if you have a prim, with HALF of it being textured 100% alpha.

The "painted" edge would fall at the center.. right?
Rotation point is at the center.. right?

the same effect can better be applied using path cuts to halve teh prim.
then there is no need for half trans textures and wont effect flexi.

you can have 2 different attachment points for wings, can not you? (sholders) attach an 100% alpha, very small sphear, as the root for the wing in question.
My ears both use this method to randomly "twitch".

Wings usually attach to a single point: the spine. The root prim is invisible and immobile, it's the two child prims that actually move (using llSetLocalRot I'd expect). llSetLocalRot won't jerk things around badly if it's used in small amounts on a flexible prim with the right parameters to prevent it from being too rigid or too "bouncy". And as has been mentioned, boxes can be made to rotate around their edge if you've cut them right. I use that trick for doors all the time. Usually cut from 0.375 - 0.625, but possibly other, depending on which edge you want the "hinge" on.

greetings!

i have learned some more things, and ALMOST got it.

1: changing the flex prims' force values will get the butterfly wings to smoothly and easily glide into place, without all that mucking about with rotations and positions and other headaches.

2: once you get the perfect flex axis and numerical values for the wing... as soon as you turn, the bloody things flex the wrong way!!! i face south, they flap right. i face north, they flap backwards. i face east or west, or even if i bend over to look at the ground, they bend all wonky! who comes up with this stuff!?!?!?


i will try cutting the flex prim and using local rots, though. that sounds promising! i hope the cut is on the right axis....

okay, guys...

the path cut is on the WRONG axis. it cuts around the z axis, but i need a cut around the x or y axis.

and apparently, the dimple setting is saved on the prim, but is ignored when changing to flex.


any other ideas? anybody KNOW? are you all snickering...!?

Try rotating the prim so the path cut works on the right axis for you? Will need to rotate the textures to compensate.

Loopi

You can't really change where path cut (or most any other of the torture tools) will be applied. You can minipulate other items to alter the end result some.

You should just be able to rotate the texture and change what angle you're rotating on to make the path cut work

Path cut ALWAYS cuts around the Z axis.. problem is, Flexi ONLY flexes the Z axis.

your solution here is either to live without flapping, or live without flexi.. or deal with wings that fall apart.

fourth option.. use 4 flexi wings. 2 open, 2 closed, and use a script to rapidly toggle alpha visibility between them.

nah, in this case you're wanting to use a llSetLinkPrimitiveParams to adjust both the rotation and the position at the same time (without a specially cut prim) so that it appears to be flapping. with how SL handles sudden changes in position/rotation over a short distance it will appear to flap when this is repeated back and forth. My serpent tail uses this same principle. just don't forget to have it halt at one position momentarily so that the flexi can appear flap to the appropriate position before it flips back.

Except recently this has stopped working as well as it used to. As far as I can tell, the viewer is rendering a position change at a different speed from a rotation change. So one of them 'snaps' to the new values, while the other 'slides in' (relatively speaking, and I don't remember if the rotation change happens faster than the position change, or vice versa). So if you have a long skinny flexi prim (which is probably what a feather would be), you end up seeing the prim jerk around instead of smoothly moving to the new position/rotation.

At least, I'm seeing this on our wings (flexi child prims). Happens on Nvidia and ATI cards. If the wings are selected/edited, the movement rendering is correct. The extent to which the effect is visibile seems to depend on frame rates... it's easier to see up in a skybox, for instance. Not so easy to see if the prims aren't flexi.

I've bug reported it and submitted a JIRA issue a long time ago, but *shrug*

I make these wings by using llSetPrimitiveParams to set both rotation and position.
Unfortionately as Ziggy posted, with a recent change to SL they now appear jerky where once they were beautifully smooth.

heyas;

sorry guys, thought i posted here. (or maybe i thought this thread was dead. ;) )


see here for the solution:

/54/85/170765/1.html


ps: good to know that the jerking around is an actual bug. because before i could make them, i saw ones that flapped smoothly. after i could make them, they all jerked around. i mean... at least it isnt me. ::sigh::

Ziggy posted the bug to JIRA - if it's affecting you, please please go vote on the issue and add any info you might have. I don't know what kind of affect voting has but maybe it will help bring this to the attention of the Lindens.

https://jira.secondlife.com/browse/VWR-332

I've made a pair of insect wings that are basically a rectangle prim each with a nice semi transparent alpha. Currently they animate by a script calling an animation on the shoulders. - but this means that the arms of my av move too. What I'd like to do is have the wings appear to flap very fast like a wasps. I imagine a show and hide thing might work? with a set of maybe six wings? 2 shown for a resting state (as though folded behind), 2 wide open, and 2 half open. Rapidly showing them in turn while the av is flying and only showing the resting state when walking. Needless to say that scripting is not my forte and I'm looking for someone to come to my rescue on this! The wings also make a buzzn sound whilst flying and using a script I got from some other wings, allow acceleration at altitude..