欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页  >  IT编程

Unity3D动态生成平面网格

程序员文章站 2023-12-11 08:03:16
在编写几何着色器的时候发现默认的plane无法满足需求,并且顶点顺序未知,于是便写了一个网格生成代码,便于生成指定大小的plane,且顶点顺序可控。 效果如下: 一...

在编写几何着色器的时候发现默认的plane无法满足需求,并且顶点顺序未知,于是便写了一个网格生成代码,便于生成指定大小的plane,且顶点顺序可控。

效果如下:

Unity3D动态生成平面网格

一个单元格由4个顶点,两个三角面组成。

四个顶点如下图

Unity3D动态生成平面网格

则生成面的顶点顺序为:

左上三角形:0 -> 1 -> 2
右下三角形:2 -> 3 -> 0

unity中顺时针绘制为正面,逆时针绘制为反面。

实现脚本如下:

//planebuilder.cs

using system.collections;
using system.collections.generic;
using unityengine;

#region editor

#if unity_editor

using unityeditor;

[customeditor(typeof(planebuilder))]
public class planebuildereditor : editor
{
 public override void oninspectorgui()
 {
 planebuilder builder = (planebuilder)target;

 editorgui.beginchangecheck();

 base.oninspectorgui();

 if (editorgui.endchangecheck())
 {
  builder.updatemesh();
 }

 if (guilayout.button("更新网格"))
 {
  builder.updatemesh();
 }
 }
}

#endif

#endregion editor

[requirecomponent(typeof(meshfilter), typeof(meshrenderer))]
public class planebuilder : monobehaviour
{
 [serializefield]
 private meshfilter _meshfilter;

 [serializefield]
 private meshrenderer _meshrenderer;

 /// <summary>
 /// 单元格大小
 /// </summary>
 [serializefield]
 private vector2 _cellsize = new vector2(1, 1);

 /// <summary>
 /// 网格大小
 /// </summary>
 [serializefield]
 private vector2int _gridsize = new vector2int(2, 2);

 public meshrenderer meshrenderer
 {
 get
 {
  return _meshrenderer;
 }
 }

 public meshfilter meshfilter
 {
 get
 {
  return _meshfilter;
 }
 }

 private void awake()
 {
 _meshfilter = getcomponent<meshfilter>();
 _meshrenderer = getcomponent<meshrenderer>();
 updatemesh();
 }

 public void updatemesh()
 {
 mesh mesh = new mesh();

 //计算plane大小
 vector2 size;
 size.x = _cellsize.x * _gridsize.x;
 size.y = _cellsize.y * _gridsize.y;

 //计算plane一半大小
 vector2 halfsize = size / 2;

 //计算顶点及uv
 list<vector3> vertices = new list<vector3>();
 list<vector2> uvs = new list<vector2>();

 vector3 vertice = vector3.zero;
 vector2 uv = vector3.zero;

 for (int y = 0; y < _gridsize.y + 1; y++)
 {
  vertice.z = y * _cellsize.y - halfsize.y;//计算顶点y轴
  uv.y = y * _cellsize.y / size.y;//计算顶点纹理坐标v

  for (int x = 0; x < _gridsize.x + 1; x++)
  {
  vertice.x = x * _cellsize.x - halfsize.x;//计算顶点x轴
  uv.x = x * _cellsize.x / size.x;//计算顶点纹理坐标u

  vertices.add(vertice);//添加到顶点数组
  uvs.add(uv);//添加到纹理坐标数组
  }
 }

 //顶点序列
 int a = 0;
 int b = 0;
 int c = 0;
 int d = 0;
 int startindex = 0;
 int[] indexs = new int[_gridsize.x * _gridsize.y * 2 * 3];//顶点序列
 for (int y = 0; y < _gridsize.y; y++)
 {
  for (int x = 0; x < _gridsize.x; x++)
  {
  //四边形四个顶点
  a = y * (_gridsize.x + 1) + x;//0
  b = (y + 1) * (_gridsize.x + 1) + x;//1
  c = b + 1;//2
  d = a + 1;//3

  //计算在数组中的起点序号
  startindex = y * _gridsize.x * 2 * 3 + x * 2 * 3;

  //左上三角形
  indexs[startindex] = a;//0
  indexs[startindex + 1] = b;//1
  indexs[startindex + 2] = c;//2

  //右下三角形
  indexs[startindex + 3] = c;//2
  indexs[startindex + 4] = d;//3
  indexs[startindex + 5] = a;//0
  }
 }

 //
 mesh.setvertices(vertices);//设置顶点
 mesh.setuvs(0, uvs);//设置uv
 mesh.setindices(indexs, meshtopology.triangles, 0);//设置顶点序列
 mesh.recalculatenormals();
 mesh.recalculatebounds();
 mesh.recalculatetangents();

 _meshfilter.mesh = mesh;
 }

#if unity_editor

 private void onvalidate()
 {
 if (null == _meshfilter)
 {
  _meshfilter = getcomponent<meshfilter>();
 }
 if (null == _meshrenderer)
 {
  _meshrenderer = getcomponent<meshrenderer>();
  if (null == _meshrenderer.sharedmaterial)
  {
  _meshrenderer.sharedmaterial = new material(shader.find("standard"));
  }
 }
 }

#endif
}

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持。