Raytrace hit / Collider - Player sinks through terrain slowly like quicksand

Here's a video to demonstrate.

I'm just checking a hit on a raytrace, setting a boolean to true when a hit is found, and only applying 'gravity' ( this is a user defined float variable ) to the vertical axis as a transform on the 'player' object.

I am calculating the hit from the bottom of the object ( no skin ) as I haven't figured out how bounds work in 3d.

 

show us your code, it could be a million and a half different things.

 

Make sure you're not raycasting under the object, lift the raycast position a bit if so.
Also, post your code, otherwise it's near impossible to tell what's actually going on.

 

Thanks for replying guys, and Merry Christmas!

I think it's something to do with the offset. I am/was tracing the raycast in the centre of the object, then assigning the offset distance from the centre to the bottom edge as a negation to the hit position, when finding where to 'push' it out the ground if it intersects slightly.

I was trying to keep it simple - the end goal is simply box collision, but I was trying to avoid using all the character controller stuff as it'd be hugely over-engineered for what will simply be a box on a conveyor belt with a simple jumping mechanic.

Script is here. Having said using a character controller would be over-engineered, the below is pretty messy...!

Code (CSharp):

1.  
2. using System.Collections;
3. using System.Collections.Generic;
4. using UnityEngine;
5.  
6. [RequireComponent (typeof (Rigidbody))]
7.  
8. public class TestMoveSimple : MonoBehaviour {
9.  
10.     public LayerMask CollisionMask; // What can I hit ?
11.     float XMov = 0f;
12.     float YMov = 0f;
13.     float ZMov = 0f;
14.     public float MyGravity = -80f;
15.     public float SkinWidth=0.45f; // offset ?::::
16.     public static string MyState; // REPORT STATUS OF OBJECT
17.     public float JumpCharge = 0f;
18.     public float JumpChargeMax = 80f;
19.     public Vector3 HitPos;  // position of hit :::
20.     public Vector3 RayTraceOrigin ;
21.     float CrossSize =2f; // Size of Debug cross
22.  
23.     //bools
24.     private bool KeysDown;
25.     private bool bHasHit=false;
26.     private bool bOnGround=false;  //
27.     private bool bJumpStart=false;  //
28.     private bool bJumping=false;  //
29.     private bool bFalling=false;  //
30.  
31.  
32.     // Use this for initialization
33.  
34.     Rigidbody MyBox;
35.     //    Canvas MyCanvas;
36.     //    Text MyTextA;
37.     //    Text MyTextB;
38.  
39.     void Start() {
40.  
41.         MyBox = GetComponent<Rigidbody> ();
42.         MyBox.mass =1;
43.         MyBox.useGravity = false;  
44.         MyBox.isKinematic = true;
45.         bJumping = false;
46.     }
47.    
48.     // Update is called once per frame
49.     void Update () {
50.         KeysDown = false;
51.  
52.         if(Input.GetKey(KeyCode.Return) || Input.GetKey(KeyCode.KeypadEnter) ){
53.             ResetAll ();
54.         }
55.  
56.         if (Input.GetKeyUp (KeyCode.Space) && bOnGround) {
57.  
58.             YMov = YMov + JumpCharge;
59.             JumpCharge = 0; // reset jump to 0 ::
60.             bJumpStart =true;
61.             bJumping = true;
62.         }
63.  
64.         if (Input.GetKey (KeyCode.LeftArrow)) {
65.             XMov += -2;
66.             KeysDown = true;
67.         }
68.  
69.         if (Input.GetKey (KeyCode.RightArrow)) {
70.             XMov += 2;
71.             KeysDown = true;
72.         }
73.  
74.  
75.         if (Input.GetKey (KeyCode.DownArrow)) {
76.             ZMov += -2;
77.             KeysDown = true;
78.         }
79.  
80.         if (Input.GetKey (KeyCode.UpArrow)) {
81.             ZMov += 2;
82.             KeysDown = true;
83.         }
84.  
85.         //jumping
86.         if (Input.GetKey (KeyCode.Space) && bOnGround) {
87.             JumpCharge += 0.2f +(JumpCharge*0.2f) ;
88.  
89.             if (JumpCharge > JumpChargeMax) {
90.                 JumpCharge = JumpChargeMax; // clamnp jumpcharge
91.             }
92.             Debug.DrawRay (MyBox.transform.position + new Vector3 (0f,-0.5f, 0f), Vector3.up*JumpCharge, Color.cyan);
93.  
94.         }
95.  
96.  
97.  
98.         if (Input.GetKeyUp (KeyCode.Space) && bOnGround) {
99.  
100.             YMov = YMov + JumpCharge;
101.             JumpCharge = 0; // reset jump to 0 ::
102.             bJumpStart =true;
103.             bJumping = true;
104.  
105.         }
106.  
107.  
108.  
109.  
110.         DebugDraw ();
111.         Move();
112.         MyState += "\n" +"\n Box Pos"+ MyBox.position + "\n RT Origin" + RayTraceOrigin;
113.         MyState += "\n Velocity" + new Vector3 (XMov * Time.deltaTime, YMov * Time.deltaTime, ZMov * Time.deltaTime);
114.     }
115.  
116.     void MyCollisions() {
117.         RaycastHit hit;
118.         bHasHit = false;
119.         bOnGround = false;
120.         MyState = "Unknown";
121.         RayTraceOrigin = MyBox.transform.position - new Vector3 (0f, SkinWidth , 0f);
122.  
123.     if (Physics.Raycast (RayTraceOrigin, Vector3.down*15f, out hit, 50f, CollisionMask)) {
124.  
125.             HitPos = hit.point;
126.  
127.             if (hit.distance < SkinWidth*1.2f && !bJumping) {
128.                 MyState = " I am on the ground ";
129.                 YMov = 0f;
130.                 bHasHit = true;
131.                 bOnGround = true;
132.                 bFalling = false;
133.                 MyBox.position = HitPos+ new Vector3 (0f, SkinWidth , 0f); ///
134.  
135.  
136.             }
137.         } else {
138.    
139.             bOnGround = false;
140.    
141.         }  
142.  
143.         if (!bOnGround) {
144.             if (YMov <= 0) {
145.                 MyState = " I am falling";
146.                 bFalling = true;
147.                 bJumping = false;
148.             }
149.             if (YMov > 0) {
150.                 MyState = " I am Jumping";
151.                 bJumping = true;
152.                 bFalling = false;
153.             }
154.         }
155.  
156.         if (MyBox.position.y < -20) {
157.             ResetAll ();
158.         }
159.     }
160.  
161.  
162.     void DebugDraw (){
163.  
164.         // draw bounds of box
165.  
166.         // show origin //
167.         Debug.DrawRay (RayTraceOrigin, Vector3.left*CrossSize*2, Color.blue);
168.         Debug.DrawRay (RayTraceOrigin, Vector3.left*-CrossSize*2, Color.blue);
169.         Debug.DrawRay (RayTraceOrigin, Vector3.forward*CrossSize*2, Color.blue);
170.         Debug.DrawRay (RayTraceOrigin, Vector3.forward*-CrossSize*2, Color.blue);  
171.  
172.  
173.         if (!bHasHit) {
174.             Debug.DrawRay (RayTraceOrigin, Vector3.down * 50f, Color.blue);
175.         }
176.  
177.         if (bHasHit && bFalling) {
178.             Debug.DrawRay (HitPos, Vector3.left*CrossSize, Color.magenta);
179.             Debug.DrawRay (HitPos, Vector3.left*-CrossSize, Color.magenta);
180.             Debug.DrawRay (HitPos, Vector3.forward*CrossSize, Color.magenta);
181.             Debug.DrawRay (HitPos, Vector3.forward*-CrossSize, Color.magenta);  
182.  
183.         }
184.  
185.  
186.         if (bJumping && bHasHit) {
187.             Debug.DrawRay (HitPos, Vector3.left*CrossSize, Color.white);
188.             Debug.DrawRay (HitPos, Vector3.left*-CrossSize, Color.white);
189.             Debug.DrawRay (HitPos, Vector3.forward*CrossSize, Color.white);
190.             Debug.DrawRay (HitPos, Vector3.forward*-CrossSize, Color.white);  
191.  
192.         }
193.  
194.         if (bOnGround) {
195.             Debug.DrawRay (HitPos, Vector3.left*CrossSize, Color.green);
196.             Debug.DrawRay (HitPos, Vector3.left*-CrossSize, Color.green);
197.             Debug.DrawRay (HitPos, Vector3.forward*CrossSize, Color.green);
198.             Debug.DrawRay (HitPos, Vector3.forward*-CrossSize, Color.green);  
199.  
200.         }
201.  
202.     }
203.  
204.  
205.  
206.  
207.     void Move() {
208.  
209.         MyCollisions();
210.  
211.         if (!KeysDown && Mathf.Abs( XMov)>0.2f  ) {
212.             XMov = XMov * 0.8f;
213.             if (Mathf.Abs (XMov) < 0.3f) {
214.                 XMov = 0.0f;
215.             }
216.         }
217.         if (!KeysDown && Mathf.Abs( ZMov)>0.2f  ) {
218.             ZMov = ZMov * 0.8f;
219.             if (Mathf.Abs (ZMov) < 0.3f) {
220.                 ZMov = 0.0f;
221.             }
222.         }
223.  
224.         if ( !bOnGround) {
225.             YMov += MyGravity*Time.deltaTime;  
226.         }
227.  
228.  
229.         if (bOnGround ) {
230.             YMov = 0f;
231.         }
232.  
233.         if (bJumpStart && !bOnGround) {
234.             bJumpStart = false;
235.         }
236.         // :: now do movement ::
237.         Vector3 MyVel ;
238.  
239.         MyVel = new Vector3 (XMov*Time.deltaTime, YMov*Time.deltaTime, ZMov * Time.deltaTime);
240.         MyBox.transform.Translate (MyVel);
241.  
242.  
243.     }
244.  
245.  
246.     void ResetAll(){
247.         Vector3 MyPos = new Vector3  (12f, 12f,-12f);
248.         MyBox.position = MyPos;
249.         MyBox.transform.SetPositionAndRotation (MyPos, Quaternion.identity);
250.         XMov = 0f;
251.         YMov = 0f;
252.         ZMov = 0f;  
253.     }
254.  
255.  
256.  
257.  
258. }
259.