TryCreatePlaneFromPolygon(Vector3[], out Plane)
GeometryUtility.TryCreatePlaneFromPolygon creates a plane from the given list of vertices that define the polygon, as long as they do not characterize a straight line or zero area.
Read time 3 minutesLast updated 4 days ago
Definition
- Type: Method
- Namespace: UnityEngine
- Assembly: UnityEngine.CoreModule
TryCreatePlaneFromPolygon(Vector3[], Plane)
public static bool TryCreatePlaneFromPolygon(Vector3[] vertices, out Plane plane)
Parameters
Returns
Type | Description |
|---|---|
| bool | Returns true on success, false if Unity did not create a plane from the vertices. |
Remarks
There must be at least three vertices to create the plane; zero, one or two vertices cause false to return with no plane. This works for concave polygons and polygons with multiple aligned vertices, but not for self-intersecting polygons.
Examples
using System.Collections;using System.Collections.Generic;using UnityEngine;// GeometryUtility.TryCreatePlaneFromPolygon - example// Attempt to draw a plane through selected positions.// Seven positions are generated close to the origin. Each position// will be in a random +/-1 xz area and random -0.5/0.5 y height.// Use these random positions for the array of vertices.// A plane is defined with the new positions. The plane is displayed// using a square Scene example.public class Example : MonoBehaviour{ private Vector3[] positions; private GameObject[] gameObjects; private int count = 7; private float timer = 999999f; private Vector3 position; void Awake() { // Generate an array of GameObjects. Use these to show where the // positions are based. gameObjects = new GameObject[count]; for (int i = 0; i < count; i++) { gameObjects[i] = GameObject.CreatePrimitive(PrimitiveType.Cube); gameObjects[i].transform.localScale = new Vector3(0.1f, 0.1f, 0.1f); gameObjects[i].name = "GO" + i.ToString(); } positions = new Vector3[count]; // Place the Camera in a sensible location. Camera.main.transform.position = new Vector3(2.0f, 1.4f, 2.0f); Camera.main.transform.localEulerAngles = new Vector3(26.0f, -135.0f, 0.0f); } private Plane plane; void Update() { // Compute positions of the 7 positions. if (timer > 5.0f) // True in first call. { // Generate an array of positions. MovePositions(count); // Now find a plane passing through the positions. GeometryUtility.TryCreatePlaneFromPolygon(positions, out plane); timer = 0.0f; } DrawPlane(Vector3.zero, plane.normal); timer += Time.deltaTime; } // Move the positions. void MovePositions(int count) { for (int i = 0; i < count; i++) { positions[i] = new Vector3(Random.Range(-1.0f, 1.0f), Random.Range(-0.5f, 0.5f), Random.Range(-1.0f, 1.0f)); gameObjects[i].transform.position = positions[i]; } } // Generate and display a square that passes through the positions. // This only works in the Scene view. void DrawPlane(Vector3 position, Vector3 normal) { Vector3 v3; if (normal.normalized != Vector3.forward) { v3 = Vector3.Cross(normal, Vector3.forward).normalized * normal.magnitude; } else { v3 = Vector3.Cross(normal, Vector3.up).normalized * normal.magnitude; } // View the square and normal. Vector3 corner0 = position + v3; Vector3 corner2 = position - v3; Quaternion q = Quaternion.AngleAxis(90.0f, normal); v3 = q * v3; Vector3 corner1 = position + v3; Vector3 corner3 = position - v3; Debug.DrawLine(corner0, corner2, Color.yellow); Debug.DrawLine(corner1, corner3, Color.yellow); Debug.DrawLine(corner0, corner1, Color.yellow); Debug.DrawLine(corner1, corner2, Color.yellow); Debug.DrawLine(corner2, corner3, Color.yellow); Debug.DrawLine(corner3, corner0, Color.yellow); Debug.DrawRay(position, normal, Color.green); // Draw lines between the positions. for (int i = 1; i < count; i++) { Debug.DrawLine(positions[i], positions[i - 1], Color.blue); } Debug.DrawLine(positions[0], positions[count - 1], Color.blue); }}