【Unity】动态生成圆环体Mesh

代码由ChatGPT生成，后经人工调整。

在这里插入图片描述

/// <summary>
/// 创建一个3维圆环体Mesh。
/// </summary>
/// <param name="outerRadius">外半径。</param>
/// <param name="innerRadius">内半径。</param>
/// <param name="numSegments">圆环体段数。值越大，圆环体越圆润。</param>
/// <param name="numSides">圆环体截面边数。值越大，圆环体截面越圆润。</param>
/// <returns></returns>
public static Mesh CreateTorus3DMesh(float outerRadius, float innerRadius, int numSegments = 32, int numSides = 16)
{Mesh mesh = new Mesh();mesh.name = "Torus";Vector3[] vertices = new Vector3[(numSegments + 1) * (numSides + 1)];Vector3[] normals = new Vector3[(numSegments + 1) * (numSides + 1)];Vector2[] uv = new Vector2[(numSegments + 1) * (numSides + 1)];int[] triangles = new int[numSegments * numSides * 6];float angleStep = 2 * Mathf.PI / numSegments;float sideAngleStep = 2 * Mathf.PI / numSides;float avgRadius = (outerRadius + innerRadius) / 2; // 平均半径float secRadius = (outerRadius - innerRadius) / 2; // 截面半径int vertexIndex = 0;for (int i = 0; i <= numSegments; i++){float segAngle = i * angleStep; // 圆环体分段角for (int j = 0; j <= numSides; j++){float sideAngle = j * sideAngleStep; // 圆环体截面角// 从right方向开始生成顶点Vector3 vertex = new Vector3{x = (avgRadius + secRadius * Mathf.Cos(sideAngle)) * Mathf.Cos(segAngle),z = (avgRadius + secRadius * Mathf.Cos(sideAngle)) * Mathf.Sin(segAngle),y = secRadius * Mathf.Sin(sideAngle)};Vector3 secCenter = new Vector3{x = avgRadius * Mathf.Cos(segAngle),z = avgRadius * Mathf.Sin(segAngle),y = 0,};vertices[vertexIndex] = vertex;normals[vertexIndex] = (vertex - secCenter).normalized;uv[vertexIndex] = new Vector2((float)i / numSegments, (float)j / numSides);vertexIndex++;}}int triangleIndex = 0;for (int i = 0; i < numSegments; i++){for (int j = 0; j < numSides; j++){int topLeft = (i + 1) * (numSides + 1) + j;int topRight = topLeft + 1;int bottomLeft = i * (numSides + 1) + j;int bottomRight = bottomLeft + 1;triangles[triangleIndex] = topLeft;triangles[triangleIndex + 1] = bottomLeft;triangles[triangleIndex + 2] = topRight;triangles[triangleIndex + 3] = topRight;triangles[triangleIndex + 4] = bottomLeft;triangles[triangleIndex + 5] = bottomRight;triangleIndex += 6;}}mesh.vertices = vertices;mesh.triangles = triangles;mesh.normals = normals;mesh.uv = uv;return mesh;
}