Reorganization and many improvements of rendering

Assets/Scripts/Editor/GenerateCone.cs

@@ -0,0 +1,157 @@
+using UnityEngine;
+using UnityEditor;
+using System;
+using System.Collections.Generic;
+
+public class GenerateCone : EditorWindow
+{
+    private int sides = 16;
+    private float baseRadius = 1f;
+    private float height = 2f;
+
+    [MenuItem("GameObject/3D Object/Cone", false, 10)]
+    static void CreateCone()
+    {
+        GameObject cone;
+        GameObject selectedObject = Selection.activeGameObject;
+
+        if (selectedObject != null)
+        {
+            // Create as child of selected object
+            cone = new GameObject("Cone");
+            cone.transform.SetParent(selectedObject.transform, false);
+        }
+        else
+        {
+            // Create as new root object
+            cone = new GameObject("Cone");
+        }
+
+        cone.AddComponent<MeshFilter>();
+        cone.AddComponent<MeshRenderer>();
+        Undo.RegisterCreatedObjectUndo(cone, "Create Cone");
+
+        var window = ScriptableObject.CreateInstance<GenerateCone>();
+        window.GenerateConeObject(cone);
+
+        Selection.activeGameObject = cone;
+    }
+
+    void GenerateConeObject(GameObject cone)
+    {
+        Mesh mesh = CreateConeMesh("ConeMesh", sides, Vector3.zero, Quaternion.identity, baseRadius, height);
+        
+        // Save the mesh as an asset
+        string path = "Assets/Meshes";
+        if (!AssetDatabase.IsValidFolder(path))
+        {
+            AssetDatabase.CreateFolder("Assets", "Meshes");
+        }
+        string assetPath = AssetDatabase.GenerateUniqueAssetPath(path + "/ConeMesh.asset");
+        AssetDatabase.CreateAsset(mesh, assetPath);
+        AssetDatabase.SaveAssets();
+
+        // Assign the mesh to the MeshFilter
+        cone.GetComponent<MeshFilter>().sharedMesh = mesh;
+        cone.GetComponent<MeshRenderer>().material = new Material(Shader.Find("Standard"));
+    }
+
+    Vector2[] GetBasePoints(int vertices, float radius)
+    {
+        const float TAU = 2f * Mathf.PI;
+        var pts = new Vector2[vertices];
+        var step = TAU / vertices; // angular step between two vertices
+        for (int i = 0; i < vertices; i++)
+        {
+            pts[i] = radius * Trig(i * step); // convert polar coordinate to cartesian space
+        }
+        return pts;
+    }
+
+    static Vector2 Trig(float rad) => new Vector2(Mathf.Cos(rad), Mathf.Sin(rad));
+
+    Vector3[] BuildConeVertices(Vector2[] baseVerts, float coneHeight)
+    {
+        if (baseVerts == null || baseVerts.Length < 3) throw new InvalidOperationException("Requires at least 3 base vertices.");
+        var verts = new Vector3[baseVerts.Length + 1];
+        verts[0] = new Vector3(0f, coneHeight, 0f);
+        for (int i = 0; i < baseVerts.Length; i++)
+        {
+            verts[i + 1] = new Vector3(baseVerts[i].x, 0f, baseVerts[i].y);
+        }
+        return verts;
+    }
+
+    void ConstructCone(Vector3[] coneVerts, List<Vector3> finalVerts, List<int> triangles)
+    {
+        if (coneVerts == null || coneVerts.Length < 4) throw new InvalidOperationException("Requires at least 4 vertices.");
+        if (finalVerts == null || triangles == null) throw new ArgumentNullException();
+
+        finalVerts.Clear();
+        triangles.Clear();
+
+        var rimVertices = coneVerts.Length - 1;
+
+        // Side faces
+        for (int i = 1; i <= rimVertices; i++)
+        {
+            int a = i, b = i < rimVertices ? i + 1 : 1;
+            AddTriangle(coneVerts[0], coneVerts[b], coneVerts[a]);
+        }
+
+        // Base face
+        for (int i = 1; i < rimVertices - 1; i++)
+        {
+            AddTriangle(coneVerts[1], coneVerts[i + 1], coneVerts[i + 2]);
+        }
+
+        void AddTriangle(Vector3 t1, Vector3 t2, Vector3 t3)
+        {
+            finalVerts.Add(t1);
+            finalVerts.Add(t2);
+            finalVerts.Add(t3);
+            triangles.Add(finalVerts.Count - 3);
+            triangles.Add(finalVerts.Count - 2);
+            triangles.Add(finalVerts.Count - 1);
+        }
+    }
+    Mesh CreateConeMesh(string name, int sides, Vector3 apex, Quaternion rotation, float baseRadius, float height)
+    {
+        var baseVerts = GetBasePoints(sides, baseRadius);
+        var coneVerts = BuildConeVertices(baseVerts, height);
+
+        var verts = new List<Vector3>();
+        var tris = new List<int>();
+        ConstructCone(coneVerts, verts, tris);
+
+        for (int i = 0; i < verts.Count; i++)
+        {
+            verts[i] = rotation * (verts[i] - coneVerts[0]);
+        }
+
+        // Recenter the cone
+        Vector3 center = CalculateCenter(verts);
+        for (int i = 0; i < verts.Count; i++)
+        {
+            verts[i] = verts[i] - center + apex;
+        }
+
+        Mesh mesh = new Mesh();
+        mesh.name = name;
+        mesh.SetVertices(verts);
+        mesh.SetTriangles(tris.ToArray(), 0);
+        mesh.RecalculateNormals();
+
+        return mesh;
+    }
+
+    Vector3 CalculateCenter(List<Vector3> vertices)
+    {
+        Vector3 sum = Vector3.zero;
+        foreach (Vector3 vert in vertices)
+        {
+            sum += vert;
+        }
+        return sum / vertices.Count;
+    }
+}

Assets/Scripts/Editor/GenerateCone.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 27925dcc8d7b5dd4ab28ed7de5b806a4
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: