Comparing two vectors

Questions
1

Hello! I’m new to Three.js and would like to create a Dual N’Back style game in 3D. One aspect of the game is pressing a button when the object appears in the same location it did x number of rounds ago and I was just wondering how you could compare the value of two vectors(?) in Three.js. Here is some code I have written so far to state the location of the cube8 object (it’s pretty basic):

		function AnotherFunction() {
		
		
		gsap.to(cube8.position,3, { y: Math.floor(Math.random()*5)});
		gsap.to(cube8.position,3, { z: Math.floor(Math.random()*5)});
              	gsap.to(cube7.position,3, { x: Math.floor(Math.random()*5)});
		gsap.to(cube7.position,3, { y: Math.floor(Math.random()*5)});
		gsap.to(cube7.position,3, { z: Math.floor(Math.random()*5)});
		gsap.to(cube6.position,3, { x: Math.floor(Math.random()*5)});
		gsap.to(cube6.position,3, { y: Math.floor(Math.random()*5)});
		gsap.to(cube6.position,3, { z: Math.floor(Math.random()*5)});
		gsap.to(cube6.position,3, { z: Math.floor(Math.random()*5)});
			
		let Vectorforcube = THREE.Vector3();
		const printlocation = cube8.getWorldPosition(Vectorforcube);			
		console.log(printlocation);

		const r3 = (Math.random()*150);		
		const g3 = (Math.floor(Math.random()*10));
		const b3 = (Math.random());
		materialf.color.setHSL(r3,g3,b3);
		renderer.render(scene, camera);
		}

Thank you for your help!

2

Well, you can use Vector3.equals() if you want to check for equality. However, if you need more flexibility because of floating point inaccuracies, you can monkey-path Vector3 with your own equals method like so:

equals( v, epsilon = Number.EPSILON ) {

    return ( ( Math.abs( v.x - this.x ) < epsilon ) && ( Math.abs( v.y - this.y ) < epsilon ) && ( Math.abs( v.z - this.z ) < epsilon ) );

}
5 Likes
3

Thanks @Mugen87 - that’s great! I’ll have to try it out this evening.

4

equals() probably would more often fail than work? Very hard to do math operations and get all three numbers to be exactly the same? It’s a good idea to check most floats with an epsilon, not just the vector.