Forums > Javascript

Using JS and GEN for 3D Math for Jitter visuals

August 13, 2012 | 12:41 am

Is it possible (and practical and efficient) to use GEN to do 3D Math (transformations) and call it via Javascript?

Currently, I’m using the sylvester javascript library to serve this function. (see – I include it by copying it to the jsextensions folder.

And it works great, except that once I begin doing many transformations using many instances generated by, things slow down and the 3d transforms are the reason for the slowdown (as far as I can tell).

Here’s just a sample of how I am using the Sylvester library.

this is a truncated js snippet:

var rightVector = codeObj.rightVector.multiply(-20.*Math.sin((p + 1) * time / 1000));
var downVector = codeObj.downVector.multiply(-30.*Math.sin((p + 1) * time / 1000));
var forwardVector = codeObj.forwardVector.multiply(-90.+codeObj.forwardAccumulation);

var resultVector=rightVector.add(downVector.add(forwardVector));

myglobal.primitivePositionMatrix.setcell(myglobal.primitiveCount, "val", resultVector.elements[0],resultVector.elements[1],resultVector.elements[2]);

Could someone show me how I would be able to use a GEN object to serve my purposes and call it via javascript? I assume that I would have to pass a message from the js script and receive a message back from GEN? Or is there another way?

If I’m not being clear, please let me know.



August 13, 2012 | 4:48 pm

Here’s how to use gen with JS. You have to create a .genjit file and load it via the @gen attribute in JS.

August 13, 2012 | 7:22 pm


@Wesley can you post an example for get/set param from gen inside JS.

Like :
A [jit.gen] file composed with [param a 0. 1. 2.] in a .genjit file ….& want to pass value to [param a]

I tried somethings like :

var gen = new JitterObject("jit.gen")
gen.gen = "coords";
gen.param = "2 2 2"; and another things but without success [of course i modify the coords.genjit file].

Thanks for your advise.

August 13, 2012 | 7:39 pm

You can do:

gen.param("a", [0.5, 0, 0]);

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Forums > Javascript