A couple of days ago I posted a video tutorial about mesh creation. I’ve had a request to make the code available so I show it off and put the code up here.
Basically it’s a mesh of the bounding volume of a projectile released with a small amount of uncertainty in the initial velocity (both magnitude and direction).
For my application of this I don’t actually render the mesh; instead I use a shader I found here to highlight the intersection between two meshes, so that the user can ‘see’ where a projectile would land. Useful for pulling off grenade tricks.
Video here (feel free to check out my other videos 
)
Code here (watch the video for an explanation of getting this up and running. Shouldn’t take any time at all)
Hope you like it, let me know if you have any problems
using UnityEngine;
using System;
using System.Collections.Generic;
[RequireComponent(typeof(MeshFilter), typeof(MeshRenderer))]
public class MeshTesting : MonoBehaviour {
private float distance;
private float height = 1.83f;
private int partNo = 30;
private int groundRes = 25;
private Vector2[] groundPos;
private float newVel;
private float[] ratio;
private float g = 9.81f;
private float initSpeed = 20f;
private float angle = 0f;
private float radius = 1f;
private int particleCounter = 0;
private Mesh mesh;
private List<Vector3> vertices;
private int[] triangles;
public Transform angleMeasurer;
private Transform _transform;
private MeshRenderer meshRenderer;
//private bool isActive = true;
public Transform cube;
private Transform[,] cubeList;
// Use this for initialization
void Start () {
meshRenderer = GetComponent<MeshRenderer>();
_transform = transform;
vertices = new List<Vector3>();
triangles = new int[groundRes*3*partNo*6];
cubeList = new Transform[groundRes,3*partNo];
GetComponent<MeshFilter>().mesh = mesh = new Mesh();
mesh.Clear();
mesh.name = "TrajectoryMesh";
float temp = 2* Mathf.PI / groundRes;
groundPos = new Vector2[groundRes];
ratio = new float[groundRes];
angle = Mathf.Deg2Rad*45f; //angle = Mathf.Deg2Rad*AngleConvert(cam.eulerAngles.x);
distance = (Mathf.Tan (angle)+Mathf.Sqrt(Mathf.Pow(Mathf.Tan (angle),2f)+height*2f*(g / Mathf.Pow (Mathf.Cos(angle)*initSpeed,2f))))/(g/ Mathf.Pow (Mathf.Cos(angle)*initSpeed,2)); //distance = MidPoint (angle);
for(int i = 0; i < groundRes; i++)
{
float ang = i * temp;
groundPos[i] = new Vector2(radius*Mathf.Cos (ang),radius*Mathf.Sin (ang));
float addon = distance + groundPos[i].y;
newVel = height+addon*Mathf.Tan (angle) < 0f ? initSpeed : Mathf.Sqrt(g*Mathf.Pow(addon/Mathf.Cos (angle),2f)/(2f*(height + addon*Mathf.Tan (angle))));
ratio[i] = groundPos[i].x/addon;
for(int j = 0; j < 3*partNo; j++)
{
float zed = (addon*(j))/partNo;
float why = -g*Mathf.Pow (zed,2f)/(2f*Mathf.Pow(Mathf.Cos(angle)*newVel,2f)) + Mathf.Tan (angle)*zed; //float why = TrajectoryHeight(angle, zed, initSpeed);
float ecks = ratio[i]*zed;
//Debug.Log (instPos + " " + particleCounter);
vertices.Add(new Vector3(ecks, why, zed));
cubeList[i,j] = Instantiate(cube, transform.TransformPoint(new Vector3(ecks,why,zed)),Quaternion.identity) as Transform;
particleCounter++;
}
}
mesh.vertices = vertices.ToArray();
for(int i = 0; i < groundRes; i++)
{
triangles[3*i + 1] = i*90 + 1;
triangles[3*i + 2] = (i+1)*90 + 1;
if(3*i+2 == 74) triangles[3*i+2] = 1;
}
for(int j = 0, k = 0; j < 40; j++)
{
for(int i = 0; i < groundRes - 1; i++)
{
triangles[74+ 6*k + 1] = 90*i + 1 + j;
triangles[74+ 6*k + 2] = 90*i + 2 + j;
triangles[74+ 6*k + 3] = 90*(i+1) + 2 + j;
triangles[74+ 6*k + 4] = 90*(i+1) + 2 + j;
triangles[74+ 6*k + 5] = 90*(i+1) + 1 + j;
triangles[74+ 6*k + 6] = 90*i + 1 + j;
k++;
}
triangles[74+ 6*k + 1] = 90*24 + 1 + j;
triangles[74+ 6*k + 2] = 90*24 + 2 + j;
triangles[74+ 6*k + 3] = 2 + j;
triangles[74+ 6*k + 4] = 2 + j;
triangles[74+ 6*k + 5] = 1 + j;
triangles[74+ 6*k + 6] = 90*24 + 1 + j;
k++;
}
mesh.triangles = triangles;
}
void Update()
{
if(meshRenderer.enabled)
{
float angle = Mathf.Atan((angleMeasurer.position.y - _transform.position.y)/(angleMeasurer.position.x - _transform.position.x));
vertices.Clear();
int count = 0;
distance = (Mathf.Tan (angle)+Mathf.Sqrt(Mathf.Pow(Mathf.Tan (angle),2f)+height*2f*(g / Mathf.Pow (Mathf.Cos(angle)*initSpeed,2f))))/(g/ Mathf.Pow (Mathf.Cos(angle)*initSpeed,2)); //distance = MidPoint (angle);
for(int j = 0; j < groundRes; j++)
{
float addon = distance + groundPos[j].y < 0 ? -(distance + groundPos[j].y) : distance + groundPos[j].y;
float newVel = height+addon*Mathf.Tan (angle) < 0 ? initSpeed : Mathf.Sqrt(g*Mathf.Pow(addon/Mathf.Cos (angle),2f)/(2f*(height + addon*Mathf.Tan (angle))));
ratio[j] = groundPos[j].x/addon;
for(int i = 0; i < 3*partNo; i++)
{
float zed = (addon*i)/partNo;
float why = -g*Mathf.Pow (zed,2f)/(2f*Mathf.Pow(Mathf.Cos(angle)*newVel,2f)) + Mathf.Tan (angle)*zed; //float why = TrajectoryHeight(angle, zed, initSpeed);
float ecks = ratio[j]*zed;
cubeList[j,i].position = transform.TransformPoint(new Vector3(ecks,why,zed));
vertices.Add(new Vector3(ecks,why,zed));
count++;
}
}
mesh.vertices = vertices.ToArray();
}
