Creature with hinge joints

1. Create a new 3D Unity project 2021.3.15f 
2. If you want to follow along, download the base scene unitypackage 
3. Import the unity package
4. open base scene

1. create a new script in the Folder 'Scripts'
2. Call it "RandomSnake"
3. copy the following code into in

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

public class RandomSnake : MonoBehaviour
{
    public GameObject headPrefab;
    public GameObject segmentPrefab;
    public int segmentCount;
    public float speed;
    public float damper;
    public float spring;
    public float changeDirectionTime = 1.0f;

    private List<GameObject> segments = new List<GameObject>();
    private GameObject head;
    private Vector3 randomDirection;
    private float timeSinceLastDirectionChange;

    void Start()
    {
        // Create head and add it to the segments list
        head = Instantiate(headPrefab, transform);
        segments.Add(head);

        // Create the segments and connect them with hinge joints
        for (int i = 0; i < segmentCount; i++)
        {
            GameObject segment = Instantiate(segmentPrefab, transform);
            HingeJoint hingeJoint = segment.AddComponent<HingeJoint>();
            hingeJoint.connectedBody = segments[i].GetComponent<Rigidbody>();
            hingeJoint.autoConfigureConnectedAnchor = false;
            hingeJoint.anchor = new Vector3(0, 0.5f, 0);
            hingeJoint.connectedAnchor = new Vector3(0, -0.5f, 0);
            hingeJoint.axis = new Vector3(1, 0, 0);

            JointSpring jointSpring = hingeJoint.spring;
            jointSpring.damper = damper;
            jointSpring.spring = spring;
            hingeJoint.spring = jointSpring;

            hingeJoint.useSpring = true;
            segments.Add(segment);
        }

        // Initialize random direction and timer
        randomDirection = Random.insideUnitSphere.normalized;
        timeSinceLastDirectionChange = 0;
    }

    void Update()
    {
        // Move the head in a random direction
        head.GetComponent<Rigidbody>().velocity = randomDirection * speed;

        // Update timer and change direction if needed
        timeSinceLastDirectionChange += Time.deltaTime;
        if (timeSinceLastDirectionChange >= changeDirectionTime)
        {
            randomDirection = Random.insideUnitSphere.normalized;
            timeSinceLastDirectionChange = 0;
        }
    }
}

1. Create a prefab for the head
2. Create a prefab for the body segments 
3. add a rigidbody to both the head and the body prefabs 

"use gravity" and "use kinematic" must be disabled for the rigidbody componens!

1. Add an empty GameObject to the scene at 0,0,0 (Camera should be at 0,0,-10)
2. Rename it "Creature"
3. Add the "RandomSnake" Script to the Creature GameObject in your scene
4. In the Inspector assign the "head" and "segment" prefabs respectively
5.  insert a segment count and values for speed, damper, and direction change time
6. Try out which values work best
7. When good values are determined, drag the Creature GameObject into Assets/Prefabs to make it a prefab

1. Create a new empty GameObject and rename it to SpawnLocation
2. Assign the SimpleSpawn script 
3. Adjust the SimpleSpawn script to add lifetime and fade the material at it's end
4. here is some info on how you can add lifetime to the creatures