[SOLVED] '.getPosition' of undefined when using it in a variable statement

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#1

So I am us .getPosition is a var statement so I can use the position of this entity in different ways. but I keep getting an error that says this

“Uncaught TypeError: Cannot read property ‘getPosition’ of undefined”

this is my var statement

var start = this.entity.getPosition();

is there a way to fix this?

#2

Hi @RoaringLegend456,

Where do you use this code? Seems that this.entity is undefined in your case.

#3

Here is the full code

var LaserEmitting = pc.createScript('laserEmitting');

// initialize code called once per entity
LaserEmitting.prototype.initialize = function() {
    setInterval(this.DoRayCast,100);
};
LaserEmitting.prototype.DoRayCast = function(){
    var color = new pc.Color(1,1,1);
    var distance = 1000;
    var start = this.entity.getPosition();
    var end = new pc.Vec3();
    end.copy(entity.forward).scale(distance).add(start);
    
    app.renderLine(start, end, color);

I had the entity not be defined but I think I fixed it because it is not showing the error anymore but is now showing this errer

#4

So you need to set the context on which your DoRayCast method runs, one way of doing it in Javascript is using bind():

setInterval(this.DoRayCast.bind(this),100);

Also here you should be using this.entity, much like you do two lines above:

end.copy(this.entity.forward).scale(distance).add(start);
#6

thanks that fixed that but it know gives me an error for ‘app’ is not defined

#7

App in the same fashion is a property of this script, so:

this.app.renderLine(start, end, color);
#8

thanks
just so i don’t run into the same issue again should I always start with the word “this” when declaring something

#9

In general you use this to assign properties to your script usually when you want them to be available in your script methods.

When requiring to store data locally e.g. in a single method, you are best using a local variable using var.

#10

thanks

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