Digital Workshop

Has anyone out there got any scripting ideas on drawing sine waves. I eventually want to use opus to construct a simulation for a Physics principle:- superposition of waves which adds the amplitudes of individual waves to give a more complex wave.

Could you create the sine wave in Flash and then use a browser object or something else to display the Flash file from within Opus?

While you can draw a static sine wave in Opus, you can't get a dynamic or travelling wave working at an acceptable speed.
This is because Opus cannot draw native curves -- you have to make up a composite curve from a series of short straight lines spaced end on end.

Paul

Thanks for taking the time to reply. I am currently trying to learn a little flash to enable me to draw moving sine waves but it is slow going. Any help would be appreciated.

Here's some ActionScript that might be of interest to you.

NbrControlPoints = 20;
StartX = 0;
EndX = Stage.width;
BottomY = Stage.height;
WaterLevel = Stage.height / 2;
WaveHeight = 30;
WaveSpeed = .0005;
_root.onEnterFrame = function() {
this.clear();
this.beginFill(0xFE9919, 100);
this.moveTo(EndX, BottomY);
for (x = 0; x < NbrControlPoints; ++x) {
var r = x / (NbrControlPoints - 1);
px = EndX + r * (StartX - EndX);
py = WaterLevel + WaveHeight * Math.sin(r * Math.PI * 2 + getTimer() * WaveSpeed);
this.lineTo(px, py);
}
this.lineTo(StartX, BottomY);
this.lineTo(EndX, BottomY);
this.endFill();
};

It creates a wave. Perhaps it can point you further to a solution? Modifying things can change the wave's peaks, speed, etc. You can do this in SwishMax if that is easier to use. It's a lot cheaper.

Have not been online for a while but could you tell me how to adapt this for swishmax as I have so far been unsuccessful.

Take a look at this. I haven't played much with it, just came across some code and tried it out to see if it would work.

Thanks for replying so promptly. I tried this in Swishmax but unfortunately all that happens is that the outline of a rectangle is drawn in red/black dotted line on a green background.

Are you testing it in a browser or external player? It doesn't do anything if you just try to play within SM.

I can display the SWF in Opus in both DocView and the Browser object. Everything works like it should.

Sorry to be a pest but I have tried what you suggested. If I run the file in SM in browser it does not quite run as it should , the sine wave is very erratic. When I try to run it in Opus nothing happens. I obviously am doing something wrong. I did type your code into flash and it worked perfectly but I am trying to use SM as the learning curve for Flash is too steep. I really want to do some wave simulations for Physics which is why I want to persevere with this.

It does work, and erratic is probably the wrong word, it's just too fast at the existing fps setting.
I've altered the variable "WaveSpeed" to make it more visually smooth at 24fps.
If you use the browser object you first load a web page that links to the
flash file.
Opus browser >> html file >> swf file.
Then it works -- see attached -- you will have to change the file path inside the browser object to the html file.

It might help you to go over the browser and docview objects in the help file.

Paul

Many thanks, got it to work. Am grateful for your efforts. If I want to adapt the code I take it that I load it into SM and then output it as a swf file. I take it that I can change your code slightly?

just load a copy of the swi file into swishMax, do what you like then do a file export as swf.
It pays to work on copies of source files like the ones with the swi extension and keep original ones as backups.
That way you can't stuff something up; most of us learnt this the hard way.

cheers
Paul

Can you explain to me how to use this script?

I've created a script object containing the script...

if I then preview the page, I get the message

Script 1[1] (3, 0) : Undefined identifier 'Stage'

Sorry to be stupid, but the wave is exactly what I'm after!

Thanks, Linda