Method subVectors

docs/app/js/sanddance-app.js:69218–69220

(a, b)

        return this.copy(a).add(b);
    }
    subVectors(a, b) {
        return this.copy(a).subtract(b);
    }
    multiplyVectors(a, b) {
        return this.copy(a).multiply(b);
    }