Re: Programming a natural looking swing (was Repulsion between physical and other objects)

llRoLookAt? brilliant! :D

Hidenori GOTO escreveu:

Hi, this is a swing I built using llRotLookAt. (non-physical)

http://youtube.com/watch?v=CO2z4meDKCw

secondlife://galonge/51/44/26/



Hidenori Glushenko
http://blog.innx.co.jp/


2008/9/5 Tigro Spottystripes tigrospottystripes@...:
  

wow! looking values up on a list is faster and easier on the sim than doing
math?! 0.0

some other time I'm gonna try to make a non-phys swing that will take
controls to let the "rider" swing back and forth, calculating in realtime
the new speeds, and I'll probably  use that arbitrary pivot trick with
llSetPrimitiveParams instead of offseting the actual center of rotation of
the linkset just for kicks Xp
    

   AnnMarie@... wrote:

       It is a long time since I did one and mine was a vertical
       motion but from memory, here is an outline on how to go about it.

       The program has two segments.  The first to generate a list of
       numbers that runs only if you change swing parameters.
       This list of numbers is used by the second program segment
       that moves the swing.
       For the first part that generates the data list:-
       You decide how many steps you want to do from peak to peak on
       the swing.
       This can be user-setable if you want to adjust smoothness.
       Divide 180 degrees by this number to get the step angle for
       looking up.
       Start at 90 degrees and step to -90 degrees (converted to
       radians) and look up the llSin() of these angles and put them
       in a list.
       This will give you a list of numbers starting at +1 and ending
       at -1.
       You now step through this list to create a second list.
       You need to scale and convert the numbers from +1 through -1
       to an angle for llSetRot().
       So +1 will correspond to the highest point on the swing, say
       35 degrees (which can be user adjustable too).
       zero will correspond to swing vertical
       -1 corresponds to swing back 35 degrees, all converted to radians.

       You run this segment as needed to create the working list that
       contains the angles that are plugged into llSetRot() only on
       rez, or when user wants to change one of the parameters.

       To run the swing have it sit at half way through the list
       (vertical) if you want it to be able to stop.
       When it starts, step through the list using a timer set to
       total swing time divided by the number of steps (can be user
       adjustable).
       You will be stepping from mid point on the list to the bottom,
       then reverse and step through to the top, then reverse again.
       On each step put the list angle value into llSetRot().

       Although it is not physical, there is some smoothing built
       into llSetRot() changes, they don't move instantaneoulsy so
       experiment to find the minimum number of steps that looks
       smooth and reduces computing overhead.

       If you want to get REALLY fancy, you can let the swing
       accelerate/decelerate on start/stop by changing the 35 degree
       angle in increasing/decreasing steps from/to zero,
       recalculating the angle list each time.

       I'm sure the above could be written to calculate the angles on
       the fly instead of using the list look-up but I did it this
       way.  It is easier to understand and is probably less
       processing load on the sim computer.

       AnnMarie Otoole.


       ----- Original Message ----- From: "G" <gcanaday@...
       gcanaday@...>
       To: <secondlifescripters@...
       secondlifescripters@...>
       Sent: Thursday, September 04, 2008 11:22 AM
       Subject: Re: Repulsion between physical and other objects



           Ann,

           oo? How does that work? /me looks for example...

           G




   _______________________________________________
   Click here to unsubscribe or manage your list subscription:

 https://lists.secondlife.com/cgi-bin/mailman/listinfo/secondlifescripters
        

_______________________________________________
Click here to unsubscribe or manage your list subscription:
https://lists.secondlife.com/cgi-bin/mailman/listinfo/secondlifescripters

    

_______________________________________________
Click here to unsubscribe or manage your list subscription:
https://lists.secondlife.com/cgi-bin/mailman/listinfo/secondlifescripters

  

_______________________________________________
Click here to unsubscribe or manage your list subscription:
https://lists.secondlife.com/cgi-bin/mailman/listinfo/secondlifescripters