Mesh Deformation

Questions & Answers
1

I’m attempting to create a mesh deformation script. My approach to this is to access each vertice in an object and then move it a certain amount based off its distance from the colliding object and the direction its being hit from. This is what I tried (the script is on the projectile that is supposed to be deforming the mesh that its hitting):

void OnCollisionEnter (Collision collision) {

		Mesh mesh = collision.transform.GetComponent<MeshFilter>().mesh;
        Vector3[] vertices = mesh.vertices;

		int i = 0;
        while (i < vertices.Length) {
			float distance = Vector3.Distance(vertices*, collision.transform.position);*

  •  	if(distance > hitRadius) return;*

  •  	float vertMove = distance/hitRadius;*

  •  	Vector3 localDirection = transform.position - collision.transform.position;*

vertices += (localDirection * vertMove);
* i++;*
* }*
* mesh.vertices = vertices;*
* mesh.RecalculateBounds();*
* }*
The problem is that it doesn’t do anything until the hitRadius is larger than the object, and then on collision, it moves the whole object. What am I doing wrong here?
EDIT
Okay so after doing some research on the forums, BigMisterB wrote this script (corrected by me):
using UnityEngine;
using System.Collections;

public class MeshDeform : MonoBehaviour {

* public Vector3 relativeVelocity;*

* void Update () {*

_ transform.Translate(relativeVelocity * Time.deltaTime);_
* }*

* void OnCollisionEnter (Collision collision) {*

* MeshFilter mf = collision.collider.GetComponent();*
* Mesh mesh = mf.mesh;*

* Vector3[] vertices = mesh.vertices;*
* Vector3 hitPoint = transform.InverseTransformPoint(collision.contacts[0].point);*
* float hitRadius = relativeVelocity.magnitude;*
* Vector3 hitDir = transform.InverseTransformDirection(-collision.contacts[0].normal);*

* int i = 0;*
* while (i < vertices.Length) {*
_ float distance = Vector3.Distance(vertices*, hitPoint);
Vector3 dir = (vertices - hitPoint);
if(dir.magnitude < hitRadius){
float amount = 1 - dir.magnitude / hitRadius;
Vector3 vertMove = hitDir * amount;
vertices += vertMove;
}
i++;
}*_

* mesh.vertices = vertices;*
* mesh.RecalculateBounds();*
* }*
}
So the script works now, but unfortunately the wrong vertices are being affected. For some reason, when I hit the object, the vertices completely opposite of the vertices that are hit are affected. Any ideas why that happens?

2

if(distance > hitRadius * speed) return;

I doubt that’s what you meant. Presumably “continue” rather than “return”. By the way, it would be a good idea to cache collision.transform.position, also transform.position. Additionally, you could optimize somewhat by using (a-b).sqrMagnitude (and the square distance) rather than Vector3.Distance.

3

I’m not sure but maybe if you use “transform.TransformPoint()” instead of “transform.InverseTransformPoint()”, it’d be working correctly.