MeshGen.cs

//using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using UnityEditor.SceneManagement;
using UnityEngine;

public class MeshGen : MonoBehaviour
{
    int treeSpokes = -1;
    float rspd = 0.175f;
    float branchWidth = 0.175f;
    public float innerHeightOffset = 2.5f;
    (Vector3[], int[], Vector3[]) genTreeVerts()
    {
        float jaggedNess = 1.1f;
        if (treeSpokes == -1)
        {
            treeSpokes = Random.Range(3, 8);
        }
        int leafSides = 12;
        int leafTriangleCount = leafSides * 3;
        int numVerts = leafTriangleCount * treeSpokes;
        //int numVerts = 3;
        float h = 0.01f;
        Vector3[] verts = new Vector3[numVerts];
        int[] triIndexes = new int[numVerts];
        Vector3[] normals = new Vector3[numVerts];
        int row = 0;


        RaycastHit hitInfo;
        bool hasHit = Physics.Raycast(Camera.main.ScreenPointToRay(Input.mousePosition), out hitInfo);

        for (var i = 0; i < numVerts; i++)
        {
            //float randomY = Random.Range(0.0f, 1.0f);
            float randomY = 0.0f;
            if (i % (leafSides * 3) == 0)
            {
                row++;
            }
            float innerRadius = 0.01f;
            float outerRadius = 0.25f;
            //float mOuterRadius = outerRadius * (2 - Mathf.Log(i + 1));
            float mOuterRadius = outerRadius * (treeSpokes - row + 5);
            
            if ((i - 1) % 3 == 0)
            {
                // Every third element should hit the middle of the "tree"
                verts[i] = new Vector3(innerRadius * Mathf.Cos(i * rspd), row + innerHeightOffset, innerRadius * Mathf.Sin(i * rspd));
                normals[i] = verts[i];
                //normals[i] = Vector3.up;
            }
            else if ((i + 1) % 3 == 0)
            {
                verts[i] = new Vector3(mOuterRadius * Mathf.Cos(i * rspd + branchWidth), row + randomY, mOuterRadius * Mathf.Sin(i * rspd + branchWidth));
                normals[i] = verts[i];
            }
            else
            {
                verts[i] = new Vector3(mOuterRadius * Mathf.Cos(i * rspd), row + randomY, mOuterRadius * Mathf.Sin(i * rspd));
                normals[i] = verts[i];
            }

            //Vector3 distToVert = hitInfo.point - verts[i];
            //verts[i] += 0.1f * distToVert;
            
            triIndexes[i] = i;
        }
        
        return (verts, triIndexes, normals);
        /*var reverseTris = new int[numVerts];
        triIndexes.CopyTo(reverseTris, 0);
        System.Array.Reverse(reverseTris);
        var allTris = new int[numVerts * 2];
        triIndexes.CopyTo(allTris, 0);
        reverseTris.CopyTo(allTris, numVerts);
        return (verts, allTris, normals);*/
    }
    MeshRenderer mr;
    Mesh m;
    MeshFilter mf;
    void Start()
    {
        mr = gameObject.AddComponent<MeshRenderer>();
        //mr.sharedMaterial = new Material(Shader.Find("Standard"));
        mr.sharedMaterial = new Material(Shader.Find("HDRP/Lit"));
        mr.sharedMaterial.SetColor("_BaseColor", Color.green);
        m = new Mesh();
        mf = gameObject.AddComponent<MeshFilter>();
    }

    // Update is called once per frame
    void Update()
    {
        var (verts, indexes, normals) = genTreeVerts();
        m.vertices = verts;
        m.triangles = indexes;
        m.normals = normals;
        mf.mesh = m;
    }
}