Forums > Jitter

screentoworld with depth


Ted
April 13, 2006 | 4:44 am

Hello,

Does anyone know a simple solution to map the screen to world when depth is involved. The following is an axample which needs modification, because the coordinates are off when depth is not zero.
Thanks.
Charles.

// create our listener object for our window
var mylistener = new JitterListener("listentestwindow",callbackfun);
var x1, y1, z1;
z1 = 0;
var zscalar = 1;
function callbackfun(event)
{
var x,y,button;
if (event.eventname=="mouse") {
// arguments are (x,y,button,cmd,shift,capslock,option,ctrl)
x = (event.args[0]-z1);
y = (event.args[1]-z1);
var world = render.screentoworld(x,y);
post("x,", x, "y", y);post();
if (event.args[6] == 0){
x1 = (world[0]);
y1 = (world[1]);
}
if (event.args[6] == 1){
x1 = world[0];
z1 = world[1] * zscalar;
}
jsketch.position = [x1, y1, z1]

}
}
callbackfun.local = 1;



VG
April 13, 2006 | 9:23 am


April 13, 2006 | 9:20 pm

Hi Charles,

Could you better formulate your question and provide a clear example
and description of what you’re expecting and what’s being returned.
Sorry but we’re too busy to make these sorts of guesses. If you
provide a z argument (as distance from the *camera*, 0-1 where 0 is
the near clipping plane and 1 is the far clipping plane), screen to
world will give you the world position at that distance from the camera.

In the following situation, perhaps you want to manipulate an
existing object. If so, I might suggest you call worldtoscreen to
determine the screen depth coordinate of the existing object first
and make use of it in your calculation. Though this is complete
speculation as I’m not sure what you’re trying to accomplish with the
following.

-Joshua


April 13, 2006 | 9:37 pm

On Apr 13, 2006, at 2:23 AM, Vincent Goudard wrote:

> I am also interested by the world2screen ferature, which
> unfortunately doesn’t appear in the render object, when
> used outside a javascript.

This will be present in Jitter 1.5.3, however for the time being, you
can make a very simple jit.gl.render wrapper in JS to accomplish this
feature. For an example of dispatching arbitrary messages (for
methods and attributes) to a JS instantiated Jitter object, you might
want to check out the jsmoviebank.js example. For example:

var myjitobj = new JitterObject("jit.whatever");

function anything()
{
//pass off all other messages to the wrapped Jitter Object
var a = arrayfromargs(arguments);

// detect if method or attribute and call method or set property
accordingly
// methods are instances of the function class, detected with the
isPrototypeOf method
if (Function.prototype.isPrototypeOf(myjitobj[messagename])) {
myjitobj[messagename](a);
} else {
myjitobj[messagename] = a;
}
}

> It seems yours is using a render and window outside a jsui, is it?

Looks like it’s a JS instantiated instance of jit.gl.render.

-Joshua


Viewing 4 posts - 1 through 4 (of 4 total)