C#の式からメッシュ作るくん

SurfaceMeshGenerator.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEditor.AssetImporters;
using UnityEditor;
using Microsoft.CodeAnalysis.CSharp.Scripting;
using Microsoft.CodeAnalysis.Scripting;

[ScriptedImporter(0, ".meshgenerator")]
public class SurfaceMeshGenerator : ScriptedImporter
{
	[SerializeField]
	Vector2Int divCount = new Vector2Int(10, 10);

	public class Inputs
	{
		public float u;
		public float v;
	}

	public async override void OnImportAsset(AssetImportContext ctx)
	{
		var text = System.IO.File.ReadAllText(ctx.assetPath);

		var options = ScriptOptions.Default.AddReferences(typeof(Vector3).Assembly).AddImports("UnityEngine");

		var script = CSharpScript.Create(text, globalsType: typeof(Inputs), options: options);

		var verticies = new List<Vector3>();
		var uvs = new List<Vector2>();

		for(int i = 0; i <= divCount.x; i++)
		{
			for(int j = 0; j <= divCount.y; j++)
			{
				var inputs = new Inputs() {
					u = (float)i / divCount.x,
					v = (float)j / divCount.y,
				};
				var pos = (Vector3)((await script.RunAsync(globals: inputs)).ReturnValue);
				verticies.Add(pos);

				uvs.Add(new Vector2(inputs.u, inputs.v));
			}
		}

		var triangles = new List<int>();
		for (int i = 0; i < divCount.x; i++)
		{
			for (int j = 0; j < divCount.y; j++)
			{
				var baseIndex = (divCount.y+1) * i + j;
				TryAddTriangle(baseIndex, baseIndex + 1, baseIndex + divCount.y + 1);
				TryAddTriangle(baseIndex+1, baseIndex + divCount.y + 2, baseIndex + divCount.y + 1);
			}
		}

		var mesh = new Mesh();
		mesh.SetVertices(verticies);
		mesh.SetTriangles(triangles, 0);
		mesh.SetUVs(0, uvs);
		mesh.RecalculateBounds();
		mesh.RecalculateNormals();

		ctx.AddObjectToAsset("main", mesh, AssetPreview.GetMiniThumbnail(mesh));
		ctx.SetMainObject(mesh);

		void TryAddTriangle(int i0, int i1, int i2)
		{
			if (verticies[i0] == verticies[i1]) return;
			if (verticies[i0] == verticies[i2]) return;
			if (verticies[i1] == verticies[i2]) return;
			triangles.Add(i0);
			triangles.Add(i1);
			triangles.Add(i2);
		}

	}

	[MenuItem("Assets/Create/📃📦Surface Mesh Generator")]
	static void CreateFile()
	{
		ProjectWindowUtil.CreateAssetWithContent("New Surface Mesh.meshgenerator", defaultCode);
		AssetDatabase.Refresh();
	}

	static string defaultCode =
@"
// Cylinder
//Quaternion.Euler(0,-u*360, 0)*(Vector3.forward*1 + Vector3.up*v*2)

// Cone
//Quaternion.Euler(0,-u*360, 0)*(Vector3.forward*(v*0.5f) + Vector3.up*v)

// Sphere
//Quaternion.Euler(Mathf.Lerp(-90f,90f,v),u*360, 0) * Vector3.forward

// Waved Plane
new Vector3(u*10f, Mathf.Sin(u*10f)*Mathf.Sin(v*10f), v*10f)

// Spiral
//Quaternion.Euler(0,-u*360*1, 0)*Vector3.forward*(v/2f+1+u-Mathf.Abs(0.5f-v)) + Vector3.up*(v+u*3)
";
}