New shapes: Ring and Disc

Packages/jp.keijiro.metamesh/Editor/Circle.cs

@@ -0,0 +1,93 @@
+using System.Collections.Generic;
+using System.Linq;
+using UnityEngine.Rendering;
+using UnityEngine;
+using Unity.Mathematics;
+
+namespace Metamesh {
+
+[System.Serializable]
+public sealed class Ring
+{
+    public float Radius = 1;
+    public float Width = 0.1f;
+    [Range(0, 1)] public float Angle = 1;
+    public uint Segments = 32;
+    public Axis Axis = Axis.Z;
+    public bool DoubleSided = false;
+
+    public void Generate(Mesh mesh)
+    {
+        // Parameter sanitization
+        var ext = math.min(Radius, Width / 2);
+
+        // Axis selection
+        var X = float3.zero;
+        var Y = float3.zero;
+        var ai = (int)Axis;
+        X[(ai + 1) % 3] = 1;
+        Y[(ai + 2) % 3] = 1;
+
+        // Vertex array
+        var vtx = new List<float3>();
+        var uv0 = new List<float2>();
+
+        var i_div_o = (Radius - Width / 2) / (Radius + Width / 2);
+
+        for (var i = 0; i < Segments; i++)
+        {
+            var phi = 2 * math.PI * Angle * ((float)i / (Segments - 1) - 0.5f);
+            var (x, y) = (math.cos(phi), math.sin(phi));
+
+            var v = x * X + y * Y;
+            vtx.Add(v * (Radius - ext));
+            vtx.Add(v * (Radius + ext));
+            uv0.Add(math.float2(-x, y) / 2 * i_div_o + 0.5f);
+            uv0.Add(math.float2(-x, y) / 2 + 0.5f);
+        }
+
+        if (DoubleSided)
+        {
+            vtx = vtx.Concat(vtx).ToList();
+            uv0 = uv0.Concat(uv0).ToList();
+        }
+
+        // Index array
+        var idx = new List<int>();
+        var n = (int)Segments;
+
+        for (var i = 0; i < n - 1; i++)
+        {
+            idx.Add(i * 2);
+            idx.Add(i * 2 + 1);
+            idx.Add(i * 2 + 2);
+
+            idx.Add(i * 2 + 1);
+            idx.Add(i * 2 + 3);
+            idx.Add(i * 2 + 2);
+        }
+
+        if (DoubleSided)
+        {
+            for (var i = 0; i < n - 1; i++)
+            {
+                idx.Add((n + i) * 2);
+                idx.Add((n + i) * 2 + 2);
+                idx.Add((n + i) * 2 + 1);
+
+                idx.Add((n + i) * 2 + 1);
+                idx.Add((n + i) * 2 + 2);
+                idx.Add((n + i) * 2 + 3);
+            }
+        }
+
+        // Mesh object construction
+        if (vtx.Count > 65535) mesh.indexFormat = IndexFormat.UInt32;
+        mesh.SetVertices(vtx.Select(v => (Vector3)v).ToList());
+        mesh.SetUVs(0, uv0.Select(v => (Vector2)v).ToList());
+        mesh.SetIndices(idx, MeshTopology.Triangles, 0);
+        mesh.RecalculateNormals();
+    }
+}
+
+} // namespace Metamesh

Packages/jp.keijiro.metamesh/Editor/Disc.cs

@@ -0,0 +1,79 @@
+using System.Collections.Generic;
+using System.Linq;
+using UnityEngine.Rendering;
+using UnityEngine;
+using Unity.Mathematics;
+
+namespace Metamesh {
+
+[System.Serializable]
+public sealed class Disc
+{
+    public float Radius = 1;
+    [Range(0, 1)] public float Angle = 1;
+    public uint Segments = 32;
+    public Axis Axis = Axis.Z;
+    public bool DoubleSided = false;
+
+    public void Generate(Mesh mesh)
+    {
+        // Axis selection
+        var X = float3.zero;
+        var Y = float3.zero;
+        var ai = (int)Axis;
+        X[(ai + 1) % 3] = 1;
+        Y[(ai + 2) % 3] = 1;
+
+        // Vertex array
+        var vtx = new List<float3>();
+        var uv0 = new List<float2>();
+
+        for (var i = 0; i < Segments; i++)
+        {
+            var phi = 2 * math.PI * Angle * ((float)i / (Segments - 1) - 0.5f);
+            var (x, y) = (math.cos(phi), math.sin(phi));
+
+            vtx.Add((x * X + y * Y) * Radius);
+            uv0.Add(math.float2(-x, y) / 2 + 0.5f);
+        }
+
+        vtx.Add(0);
+        uv0.Add(0.5f);
+
+        if (DoubleSided)
+        {
+            vtx = vtx.Concat(vtx).ToList();
+            uv0 = uv0.Concat(uv0).ToList();
+        }
+
+        // Index array
+        var idx = new List<int>();
+        var n = (int)Segments;
+
+        for (var i = 0; i < n - 1; i++)
+        {
+            idx.Add(n);
+            idx.Add(i);
+            idx.Add(i + 1);
+        }
+
+        if (DoubleSided)
+        {
+            for (var i = 0; i < n - 1; i++)
+            {
+                idx.Add(n + 1 + n);
+                idx.Add(n + 1 + i + 1);
+                idx.Add(n + 1 + i);
+            }
+        }
+
+        // Mesh object construction
+        if (vtx.Count > 65535) mesh.indexFormat = IndexFormat.UInt32;
+        mesh.SetVertices(vtx.Select(v => (Vector3)v).ToList());
+        mesh.SetUVs(0, uv0.Select(v => (Vector2)v).ToList());
+        mesh.SetIndices(idx, MeshTopology.Triangles, 0);
+        mesh.RecalculateNormals();
+    }
+}
+
+} // namespace Metamesh

Packages/jp.keijiro.metamesh/Editor/Enums.cs

@@ -1,6 +1,6 @@
 namespace Metamesh {
 
-public enum Shape { Plane, Box, Sphere, Icosphere, Cylinder, RoundedBox }
+public enum Shape { Plane, Box, Sphere, Icosphere, Cylinder, RoundedBox, Ring, Disc }
 public enum Axis { X, Y, Z }
 
 } // namespace Metamesh

Packages/jp.keijiro.metamesh/Editor/MetameshImporter.cs

@@ -20,6 +20,8 @@ public sealed class MetameshImporter : ScriptedImporter
     [SerializeField] Icosphere _icosphere = new Icosphere();
     [SerializeField] Cylinder _cylinder = new Cylinder();
     [SerializeField] RoundedBox _roundedBox = new RoundedBox();
+    [SerializeField] Ring _ring = new Ring();
+    [SerializeField] Disc _disc = new Disc();
 
     public override void OnImportAsset(AssetImportContext context)
     {
@@ -56,6 +58,8 @@ Mesh ImportAsMesh(string path)
             case Shape.Icosphere  : _icosphere .Generate(mesh); break;
             case Shape.Cylinder   : _cylinder  .Generate(mesh); break;
             case Shape.RoundedBox : _roundedBox.Generate(mesh); break;
+            case Shape.Ring       : _ring      .Generate(mesh); break;
+            case Shape.Disc       : _disc      .Generate(mesh); break;
         }
 
         mesh.RecalculateBounds();

Packages/jp.keijiro.metamesh/Editor/MetameshImporterEditor.cs

@@ -18,6 +18,8 @@ sealed class MetameshImporterEditor : ScriptedImporterEditor
     SerializedProperty _icosphere;
     SerializedProperty _cylinder;
     SerializedProperty _roundedBox;
+    SerializedProperty _ring;
+    SerializedProperty _disc;
 
     public override void OnEnable()
     {
@@ -29,6 +31,8 @@ public override void OnEnable()
         _icosphere  = serializedObject.FindProperty("_icosphere");
         _cylinder   = serializedObject.FindProperty("_cylinder");
         _roundedBox = serializedObject.FindProperty("_roundedBox");
+        _ring       = serializedObject.FindProperty("_ring");
+        _disc       = serializedObject.FindProperty("_disc");
     }
 
     public override void OnInspectorGUI()
@@ -45,6 +49,8 @@ public override void OnInspectorGUI()
             case Shape.Icosphere : EditorGUILayout.PropertyField(_icosphere);  break;
             case Shape.Cylinder  : EditorGUILayout.PropertyField(_cylinder);   break;
             case Shape.RoundedBox: EditorGUILayout.PropertyField(_roundedBox); break;
+            case Shape.Ring      : EditorGUILayout.PropertyField(_ring);       break;
+            case Shape.Disc      : EditorGUILayout.PropertyField(_disc);       break;
         }
 
         serializedObject.ApplyModifiedProperties();