README.md

Spider tutorial EP 1

Video: https://youtu.be/EdjAYrssxDM

Hope you enjoyed the video!

if you have any questions please don't hesitate to join the discord. You are all welcome!

Discord: https://discord.gg/pVQsS79FQh

OrangeSpider Asset: https://assetstore.unity.com/packages/3d/characters/robots/spider-orange-181154

Hope you enjoy this series!

code used will be below if you dont want to dig into the files!

Body Controller code:

public class bodyController : MonoBehaviour {

Vector3 velocity;
Vector3 lastVelocity = Vector3.one;
Vector3 lastSpiderPosition;
Vector3[] legPositions;
Vector3[] legOriginalPositions;
List<int> nextIndexToMove = new List<int>();
List<int> IndexMoving = new List<int>();
Vector3 lastBodyUp;
List<int> oppositeLeg = new List<int>();
bool currentLeg = true;
float resetTimer = 0.5f;

[Space(10)]
[Header("GameObject Assignment")]
[Space(10)]

public GameObject spider;
public GameObject[] legTargets;
public GameObject[] legCubes;

[Space(10)]
[Header("Rotation of Body and Movment of leg")]
[Space(10)]

public bool enableBodyRotation = false;
public bool enableMovementRotation = false;
public bool rigidBodyController;

[Space(10)]
[Header("Values for leg Movement")]
[Space(10)]

public float moveDistance = 0.7f;
public float stepHeight = .15f;
public float spiderJitterCutOff = 0f;
public int waitTimeBetweenEveryStep = 0;
public float LegSmoothness = 8;
public float BodySmoothness = 8;
public float OverStepMultiplier = 4;


void Start()
{
    lastBodyUp = transform.up;

    legPositions = new Vector3[legTargets.Length];
    legOriginalPositions = new Vector3[legTargets.Length];

    for (int i = 0; i < legTargets.Length; i++)
    {
        legPositions[i] = legTargets[i].transform.position;
        legOriginalPositions[i] = legTargets[i].transform.position;

        if (currentLeg) { oppositeLeg.Add(i + 1); currentLeg = false; }
        else if (!currentLeg) { oppositeLeg.Add(i - 1); currentLeg = true; }
    }

    lastSpiderPosition = spider.transform.position;

    rotateBody();
}


void FixedUpdate()
{
    velocity = spider.transform.position - lastSpiderPosition;
    velocity = (velocity + BodySmoothness * lastVelocity) / (BodySmoothness + 1f);

    moveLegs();
    rotateBody();


    lastSpiderPosition = spider.transform.position;
    lastVelocity = velocity;
}

void moveLegs()
{
    if (!enableMovementRotation) return;
    for (int i = 0; i < legTargets.Length; i++)
    {
        if (Vector3.Distance(legTargets[i].transform.position, legCubes[i].transform.position) >= moveDistance)
        {
            if (!nextIndexToMove.Contains(i) && !IndexMoving.Contains(i)) nextIndexToMove.Add(i);
        }
        else if (!IndexMoving.Contains(i))
        {
            legTargets[i].transform.position = legOriginalPositions[i];
        }

    }

    if (nextIndexToMove.Count == 0 || IndexMoving.Count != 0) return;
    Vector3 targetPosition = legCubes[nextIndexToMove[0]].transform.position + Mathf.Clamp(velocity.magnitude * OverStepMultiplier, 0.0f, 1.5f) * (legCubes[nextIndexToMove[0]].transform.position - legTargets[nextIndexToMove[0]].transform.position) + velocity * OverStepMultiplier;
    StartCoroutine(step(nextIndexToMove[0], targetPosition, false));
}

IEnumerator step(int index, Vector3 moveTo, bool isOpposite)
{
    if (!isOpposite) moveOppisteLeg(oppositeLeg[index]);

    if (nextIndexToMove.Contains(index)) nextIndexToMove.Remove(index);

    if (!IndexMoving.Contains(index)) IndexMoving.Add(index);

    Vector3 startPos = legOriginalPositions[index];

    for (int i = 1; i <= LegSmoothness; ++i)
    {
        legTargets[index].transform.position = Vector3.Lerp(startPos, moveTo + new Vector3(0, Mathf.Sin(i / (float)(LegSmoothness + spiderJitterCutOff) * Mathf.PI) * stepHeight, 0), (i / LegSmoothness + spiderJitterCutOff));
        yield return new WaitForFixedUpdate();
    }


    legOriginalPositions[index] = moveTo;


    for (int i = 1; i <= waitTimeBetweenEveryStep; ++i) yield return new WaitForFixedUpdate();

    if (IndexMoving.Contains(index)) IndexMoving.Remove(index);

}

void moveOppisteLeg(int index)
{
    Vector3 targetPosition = legCubes[index].transform.position + Mathf.Clamp(velocity.magnitude * OverStepMultiplier, 0.0f, 1.5f) * (legCubes[index].transform.position - legTargets[index].transform.position) + velocity * OverStepMultiplier;
    StartCoroutine(step(index, targetPosition, true));
}

void rotateBody()
{
    if (!enableBodyRotation) return;

    Vector3 v1 = legTargets[0].transform.position - legTargets[1].transform.position;
    Vector3 v2 = legTargets[2].transform.position - legTargets[3].transform.position;
    Vector3 normal = Vector3.Cross(v1, v2).normalized;
    Vector3 up = Vector3.Lerp(lastBodyUp, normal, 1f / (float)(BodySmoothness));
    transform.up = up;
    if (!rigidBodyController) transform.rotation = Quaternion.LookRotation(transform.parent.forward, up);
    lastBodyUp = transform.up;
}

}

Leg aim grounding code:

public class LegAimGrounding : MonoBehaviour {

GameObject raycastOrigin;
int layerMask;
void Start()
{
    layerMask = LayerMask.GetMask("Ground");
    raycastOrigin = transform.parent.gameObject;
}

void Update()
{
    RaycastHit hit;
    if(Physics.Raycast(raycastOrigin.transform.position, -transform.up, out hit, Mathf.Infinity, layerMask))
    {
        transform.position = hit.point;
    }
}

}

basic spider controller:

public class simpleController : MonoBehaviour {

public Rigidbody cntroller;
public Transform cam;

public float speed = 6;
Vector3 velocity;

float turnSmoothVelocity;
public float turnSmoothTime = 0.1f;

void Update()
{

    float horizontal = Input.GetAxisRaw("Horizontal");
    float vertical = Input.GetAxisRaw("Vertical");
    Vector3 direction = new Vector3(horizontal, 0f, vertical).normalized;

    if (direction.magnitude >= 0.1f && cntroller.velocity.magnitude < 4)
    {
        float targetAngle = Mathf.Atan2(direction.x, direction.z) * Mathf.Rad2Deg + cam.eulerAngles.y;

        Vector3 moveDir = Quaternion.Euler(0f, targetAngle, 0f) * Vector3.forward;
        cntroller.AddForce(moveDir.normalized * speed * Time.deltaTime);
    }
}

}

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