updateAgentPositions(target, dt ){

        this.crowd.timeStep = dt

        this.crowd.update(dt)

        let i = 0

        const targetPosition = this.navMeshQuery.getClosestPoint(target)

        while(i < this.agents.length ){

            const agent = this.agents[i]

            agent.goto(targetPosition);

            const agentPosition = agent.position();

            agent.model3D.position.set(agentPosition.x, agentPosition.y, agentPosition.z)

            i++
        }
    }

createAgent( position = {x: 0, y: 0, z: 0}, radius = 2){

        this.navMeshQuery.getClosestPoint(position);

        /* get a random point around the given position */
        const initialAgentPosition = this.navMeshQuery.getRandomPointAround(position, radius)
    
        const speed = (Math.random() * 10 + 10);
        const agent = this.crowd.addAgent(initialAgentPosition, {
            radius: radius,
            height: radius,
            maxAcceleration: speed * 10,
            maxSpeed: speed,
            collisionQueryRange: 0.5,
            pathOptimizationRange: 0,
            separationWeight: 1.0
          });
        
        agent.model3D = new Mesh(new SphereGeometry(radius,10, 10), new MeshBasicMaterial({ color: Math.random()* 0xffffff, wireframe: true }))

        this.agents.push( agent )

        return agent

    }