SoftBody

using UnityEngine;

public class SoftBody : MonoBehaviour {

    [Range(0, 1f)]
    public float forceMultiplier = 0.025f;
    public float range = 0.2f;

    private int i;
    private int k;
    private Vector3 force;
    private Vector3[] vertices;
    private Mesh mesh;
    private Vector3 localPosition;
    private float distance;

    private void Start() {
        var filter = GetComponent<MeshFilter>();
        mesh = Instantiate<Mesh>(filter.sharedMesh);
        filter.mesh = mesh;
        mesh.Optimize();
    }

    private void OnCollisionEnter(Collision collision) {
        if(collision.contacts.Length > 0)
            for(i = 0; i < collision.contacts.Length; i++) {
                force = collision.relativeVelocity;
                force *= forceMultiplier;

                DeformMeshes(collision.contacts[i].point, force);
            }
    }

    private void DeformMeshes(Vector3 position, Vector3 force) {

        localPosition = transform.InverseTransformPoint(position);
        vertices = mesh.vertices;
        for(k = 0; k < vertices.Length; k++) {
            distance = Mathf.Clamp01(range - (localPosition - vertices[k]).sqrMagnitude);
            vertices[k] = Vector3.Slerp(vertices[k], vertices[k] - force, distance);
        }
        mesh.vertices = vertices;
        mesh.RecalculateBounds();
        mesh.RecalculateNormals();
    }
}