Mesh网格编程(一) 流体水
2016-06-30 08:54
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通过Mesh网格随Sin函数实时变化模拟液体的流动,从而达到动态水的效果。
其一是棱角分明的几何体,这种几何体的法线可以用确定好的顶点坐标两两相减,得到的向量做叉乘并赋值给三个顶点上的法线。
其二是圆滑的几何体,这种几何体需要求出该点在曲面上的切线,从而确定垂直于切线的法线。如果是圆形。可以使用顶点减圆心所得的向量。
此外,求得的法线尽量单位化,否则可能出现一个面上的颜色不同。
注:波浪上方的面为曲面,故使用切线求法线。其他面很有规则,并没有使用叉乘的方法。
几何体没有使用UV贴图,newUVs没有赋值。
原文链接:http://blog.csdn.net/qq_18408937/article/details/44161229
Mesh网格编程步骤:
一:确定数量
确定该几何图形应有多少个三角形面,顶点坐标、顶点序列、UV贴图、法线向量皆为三角形面数的三倍。二:根据三角形面确定顶点坐标
这里我习惯把一个面的顶点确定好之后再去找下一个面,这样做可以是法线和顶点序列确定起来很容易。但是要注意的是在确定顶点时要按照顺时针顺序确定,否则会导致三角形面相反。三:确定法线
法线大致分为两种:其一是棱角分明的几何体,这种几何体的法线可以用确定好的顶点坐标两两相减,得到的向量做叉乘并赋值给三个顶点上的法线。
其二是圆滑的几何体,这种几何体需要求出该点在曲面上的切线,从而确定垂直于切线的法线。如果是圆形。可以使用顶点减圆心所得的向量。
此外,求得的法线尽量单位化,否则可能出现一个面上的颜色不同。
四:确定顶点序列
若三角形顶点按照面数去确定,顶点序列就会变得非常简单,按顺序赋值即可。五:确定UV贴图
根据所做几何体的不同,贴图左边也会有所改变,并不固定。六:创建网格
using UnityEngine; using System.Collections; public class Water : MonoBehaviour { Mesh mesh; public int tier = 10; //长度分段 private float length = 10; //长 private int width = 3; //宽 private int hight = 10; //高 private Vector3[] vs; //顶点坐标 private int[] ts; //顶点序列 private Vector2[] newUVs; //UV贴图 private Vector3[] newNormals; //法线 void Update () { int temp = ((tier + 1) * 8 + 4) * 3; //确定顶点数量 vs = new Vector3[temp]; ts = new int[temp]; newUVs = new Vector2[temp]; newNormals = new Vector3[temp]; float dis = 2 * Mathf.PI / tier; //两段之差的横坐标 int count = 0; for (int i = 0; i < tier; i++) { float pos1 = i * length / tier - length / 2; float pos2 = (i + 1) * length / tier - length / 2; //顶面顶点坐标 vs[count] = new Vector3(pos1,Mathf.Sin(Time.time + i * dis), width); vs[count + 1] = new Vector3(pos2,Mathf.Sin(Time.time + (i + 1) * dis), -width); vs[count + 2] = new Vector3(pos1,Mathf.Sin(Time.time + i * dis), -width); vs[count + 3] = new Vector3(pos1,Mathf.Sin(Time.time + i * dis), width); vs[count + 4] = new Vector3(pos2,Mathf.Sin(Time.time + (i + 1) * dis), width); vs[count + 5] = new Vector3(pos2,Mathf.Sin(Time.time + (i + 1) * dis), -width); //顶面法线 newNormals[count] = Vector3.Normalize(new Vector3(1,Mathf.Cos(Time.time + i * dis), 0)); newNormals[count + 1] = Vector3.Normalize(new Vector3(1,Mathf.Cos(Time.time + (i + 1) * dis), 0)); newNormals[count + 2] = Vector3.Normalize(new Vector3(1,Mathf.Cos(Time.time + i * dis), 0)); newNormals[count + 3] = Vector3.Normalize(new Vector3(1,Mathf.Cos(Time.time + i * dis), 0)); newNormals[count + 4] = Vector3.Normalize(new Vector3(1,Mathf.Cos(Time.time + (i + 1) * dis), 0)); newNormals[count + 5] = Vector3.Normalize(new Vector3(1,Mathf.Cos(Time.time + (i + 1) * dis), 0)); //前面顶点坐标 vs[count + 6] = new Vector3(pos1,Mathf.Sin(Time.time + i * dis), -width); vs[count + 7] = new Vector3(pos2,-hight, -width); vs[count + 8] = new Vector3(pos1,-hight, -width); vs[count + 9] = new Vector3(pos1,Mathf.Sin(Time.time + i * dis), -width); vs[count + 10] = new Vector3(pos2,Mathf.Sin(Time.time + (i + 1) * dis), -width); vs[count + 11] = new Vector3(pos2,-hight, -width); //前面法线 for (int j = 0; j < 6; j++) { newNormals[count + 6 + j] = Vector3.back; } //后面顶点坐标 vs[count + 12] = new Vector3(pos1,Mathf.Sin(Time.time + i * dis), width); vs[count + 13] = new Vector3(pos1,-hight, width); vs[count + 14] = new Vector3(pos2,-hight, width); vs[count + 15] = new Vector3(pos1,Mathf.Sin(Time.time + i * dis), width); vs[count + 16] = new Vector3(pos2,-hight, width); vs[count + 17] = new Vector3(pos2,Mathf.Sin(Time.time + (i + 1) * dis), width); //后面法线 for (int j = 0; j < 6; j++) { newNormals[count + 12 + j] = Vector3.forward; } //下面顶点坐标 vs[count + 18] = new Vector3(pos1,-hight, width); vs[count + 19] = new Vector3(pos1,-hight, -width); vs[count + 20] = new Vector3(pos2,-hight, -width); vs[count + 21] = new Vector3(pos1,-hight, width); vs[count + 22] = new Vector3(pos2,-hight, -width); vs[count + 23] = new Vector3(pos2,-hight, width); //下面法线 for (int j = 0; j < 6; j++) { newNormals[count + 18 + j] = Vector3.down; } count += 24; } //两侧顶点坐标及法线 vs [vs.Length - 12] = new Vector3 (-length / 2, Mathf.Sin (Time.time), width); vs [vs.Length - 11] = new Vector3 (-length / 2, -hight, -width); vs [vs.Length - 10] = new Vector3 (-length / 2, -hight, width); vs [vs.Length - 9] = new Vector3 (-length / 2, Mathf.Sin (Time.time), width); vs [vs.Length - 8] = new Vector3 (-length / 2, Mathf.Sin (Time.time), -width); vs [vs.Length - 7] = new Vector3 (-length / 2, -hight, -width); for (int j = 0; j < 6; j++) { newNormals[vs.Length - 12 + j] = Vector3.left; } vs [vs.Length - 6] = new Vector3 (length / 2, Mathf.Sin (Time.time + tier * dis), width); vs [vs.Length - 5] = new Vector3 (length / 2, -hight, width); vs [vs.Length - 4] = new Vector3 (length / 2, -hight, -width); vs [vs.Length - 3] = new Vector3 (length / 2, Mathf.Sin (Time.time + tier * dis), width); vs [vs.Length - 2] = new Vector3 (length / 2, -hight, -width); vs [vs.Length - 1] = new Vector3 (length / 2, Mathf.Sin (Time.time + tier * dis), -width); for (int j = 0; j < 6; j++) { newNormals[vs.Length - 6 + j] = Vector3.right; } for (int i = 0; i < ts.Length; i++) { //顶点序列赋值 ts[i] = i; } mesh = new Mesh(); GetComponent<MeshFilter>().mesh = mesh; mesh.vertices = vs; mesh.uv = newUVs; mesh.triangles = ts; mesh.normals = newNormals; } }
注:波浪上方的面为曲面,故使用切线求法线。其他面很有规则,并没有使用叉乘的方法。
几何体没有使用UV贴图,newUVs没有赋值。
原文链接:http://blog.csdn.net/qq_18408937/article/details/44161229