How to make the snake grow in size using C# in Unity in 3D?

Questions & Answers
1

I have an assignment that asked to make a retro game using Unity. My snake head can move around but cannot grow in size when collecting item. Help?

This is my script:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class control: MonoBehaviour {

public List<Transform> BodyParts = new List<Transform>();

public float mindistance = 0.25f;

public int beginsize;

public float speed = 1;
public float rotationspeed = 50;

public float TimeFromLastRetry;

public GameObject bodyprefab;

private float dis;
private Transform curBodyPart;
private Transform PrevBodypart;

public bool IsAlive;

private Rigidbody rb;
private GameManager gm;

// Use this for initialization
void Start () {

	rb = GetComponent<Rigidbody> ();

	GameObject thescore = GameObject.Find ("Game Manager");
	gm = thescore.GetComponent<GameManager> ();

}

// Update is called once per frame
void Update () {

	float moveHorizontal = Input.GetAxis ("Horizontal");
	float moveVertical = Input.GetAxis ("Vertical");

	Vector3 movement = new Vector3 (moveHorizontal, 0.0f, moveVertical);
	//get direction from the values

	rb.AddForce (movement * speed);
	//addForce = how strong the ball is pushed

}

void OnTriggerEnter(Collider other){
	if(other.gameObject.CompareTag ("Pick Up")){
		other.gameObject.SetActive(false);

		gm.score = gm.score + 1;
		gm.SetScore ();
	}
}

public void Move()
{
	float curspeed = speed; //snake always move

	if (Input.GetKey(KeyCode.W))
		curspeed *=2;

	BodyParts [0].Translate (BodyParts [0].forward * curspeed * Time.smoothDeltaTime, Space.World);

	if (Input.GetAxis ("Horizontal") != 0)
		BodyParts [0].Rotate (Vector3.up * rotationspeed * Time.deltaTime * Input.GetAxis ("Horizontal"));

	for (int i = 1; i < BodyParts.Count; i++ )
	{
		curBodyPart = BodyParts *;*

  •   	PrevBodypart = BodyParts [i - 1];*

  •   	dis = Vector3.Distance (PrevBodypart.position, curBodyPart.position);*

  •   	Vector3 newpos = PrevBodypart.position;*

  •   	newpos.y = BodyParts[0].position.y;*

_ float T = Time.deltaTime * dis / mindistance * curspeed;_

  •   	if (T > 0.5f)*

  •   		T = 0.5f;*

  •   	curBodyPart.position = Vector3.Slerp (curBodyPart.position, newpos, T);*

  •   	curBodyPart.rotation = Quaternion.Slerp (curBodyPart.rotation, PrevBodypart.rotation, T);*

  •   }*
  • }*
  • public void AddBodyPart()*
  • {*
  •   Transform newpart = (Instantiate (bodyprefab, BodyParts [BodyParts.Count - 1].position, BodyParts [BodyParts.Count - 1].rotation) as GameObject).transform;*

  •   newpart.SetParent (transform);*

  •   BodyParts.Add (newpart);*
  • }*

}

2

You never call AddBodyPart() maybe add it to OnTrigger function.

 void OnTriggerEnter(Collider other){
         if(other.gameObject.CompareTag ("Pick Up")){
             other.gameObject.SetActive(false);
             gm.score = gm.score + 1;
             gm.SetScore ();
             AddBodyPart();
         }
     }

EDIT :
Also you might want to match the velocity as well :

private void AddBodyPart()
    {
        var newpart = Instantiate(
                                  bodyprefab,
                                  BodyParts[BodyParts.Count - 1].position,
                                  BodyParts[BodyParts.Count - 1].rotation).transform;
        newpart.position = new Vector3(
                                       BodyParts[BodyParts.Count - 1].position.x,
                                       BodyParts[BodyParts.Count - 1].position.y,
                                       BodyParts[BodyParts.Count - 1].position.z - 1);

        newpart.GetComponent<Rigidbody>().velocity = BodyParts[BodyParts.Count - 1]
            .gameObject.GetComponent<Rigidbody>().velocity;
        newpart.SetParent(transform);
        BodyParts.Add(newpart);
    }