CODEWITHSUNDEEP
c#unity-game-enginegame-physics
m0a
m0a

Reputation: 1005

LineRenderer not drawing where Mouse clicks

Following a tutorial, I'm trying to use a grappling gun mechanic that utilizes a spring joint and Line Renderer.

I've got the line drawing upon mouseclick, but the end of the line is not drawing where the user clicks.

It looks like this:

Can anyone kind of help me out as to why it's not working? Here's the (wonky) project in action- https://i.imgur.com/IuMsEsQ.mp4

Grappling gun code:

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

public class GrapplingGun : MonoBehaviour
{
    private LineRenderer lr;
    private Vector3 grapplePoint; //where we grapple to
    public LayerMask whatIsGrappable;
    public Transform gunTip;
    public Transform cam;
    public Transform player;
    private float maxDistance = 100f;
    private SpringJoint joint;

    void Awake()
    {
        lr = GetComponent<LineRenderer>();
    }

    void Update()
    {


        if (Input.GetMouseButtonDown(0))
        {
            StartGrapple();
        }
        else if (Input.GetMouseButtonUp(0))
        {
            StopGrapple();
        }
    }

    void LateUpdate()
    {
        DrawRope();
    }

    void StartGrapple()
    {
        RaycastHit hit;
        if (Physics.Raycast(cam.position, cam.forward, out hit, maxDistance, whatIsGrappable))
        //if (Physics.Raycast(transform.position, Vector3.forward, out hit, maxDistance, whatIsGrappable))
        {
            grapplePoint = hit.point;
            joint = player.gameObject.AddComponent<SpringJoint>();
            joint.autoConfigureConnectedAnchor = false;
            joint.connectedAnchor = grapplePoint;

            float distanceFromPoint = Vector3.Distance(player.position, grapplePoint);
            joint.maxDistance = distanceFromPoint * 0.8f;
            joint.minDistance = distanceFromPoint * 0.25f;

            joint.spring = 4.5f;
            joint.damper = 7f;
            joint.massScale = 4.5f;

            lr.positionCount = 2;
        }

    }

    void DrawRope()
    {
        //If not grappling, don't draw anything
        if (!joint) return;

        lr.SetPosition(0, gunTip.position);
        lr.SetPosition(1, grapplePoint);
    }
    void StopGrapple()
    {
        lr.positionCount = 0;
        Destroy(joint);
    }
}

Thank you.

Upvotes: 0

Views: 239

Answers (1)

Zami
Zami

Reputation: 113

The underlying issue is your raycast. the second parameter is the direction of the ray, which you have as the camera direction. Currently your ray is pointing forward from the camera at all times as a result.

What you can do is use Camera.ScreenPointToRay to give a ray to cast along to give you a 3d mouse position to cast to, then use your current raycast but replace the second parameter with the direction from the player to the point hit by the raycast from the function mentioned before

Ray ray = Camera.ScreenPointToRay(Input.mousePosition);
Physics.Raycast(ray, out RaycastHit hit);
if (Physics.Raycast(transform.position, (hit.point - transform.position).normalized, out hit, maxDistance, whatIsGrappable)) {
    // Your code here...
}

Upvotes: 1

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