前提知识
Mesh & SharedMesh
- 在Mesh中存储着三维模型的数据：vertices（顶点数据数组Vector3[]）、triangles（三角形顶点索引数组，int[])、normals（法线向量数组，Vector3[])、uv（纹理坐标数组，Vector2[])。
- sharedMesh是公用的，是引用传递。而mesh是值传递，是各自拥有的实例。sharedMesh改变，则所有的使用到此mesh的都改变。(如果一堆meshfilter是多次clone出来的，那么sharedMesh就是一样的，改变一个的sharedMesh就会改变所有的。而mesh是那个引用在某个具体object的拷贝，改变mesh只改变当前对象。)
Mesh Filter & Mesh Render
- Mesh Filter是用了一个从资源里取到的mesh资源，然后通过Mesh Render，渲染到屏幕中
什么是UV坐标
- 对于三维模型，有两个最重要的坐标系统，一是顶点的位置（X，Y，Z）坐标，另一个就是UV坐标。什么是UV？简单的说，就是贴图影射到模型表面的依据。 完整的说，其实应该是UVW（因为XYZ已经用过了，所以另选三个字母表示）。U和V分别是图片在显示器水平、垂直方向上的坐标，取值一般都是0~1，也 就是（水平方向的第U个像素/图片宽度，垂直方向的第V个像素/图片高度）。那W呢？贴图是二维的，何来三个坐标？嗯嗯，W的方向垂直于显示器表面，一般 用于程序贴图或者某些3D贴图技术（记住，确实有三维贴图这种概念！），对于游戏而言不常用到，所以一般我们就简称UV了。
- 所有的图象文件都是二维的一个平面。水平方向是U，垂直方向是V，通过这个平面的，二维的UV坐标系。我们可以定位图象上的任意一个象素。但是一个问题是如何把这个二维的平面贴到三维的NURBS表面和多边形表面呢？ 对于NURBS表面。由于他本身具有UV参数，尽管这个UV值是用来定位表面上的点的参数，但由于它也是二维的，所以很容易通过换算把表面上的点和平面图象上的象素对应起来。所以把图象贴带NURBS是很直接的一件事。但是对于多变形模型来讲，贴图就变成一件麻烦的事了。所以多边形为了贴图就额外引进了一个UV坐标，以便把多边形的顶点和图象文件上的象素对应起来，这样才能在多边形表面上定位纹理贴图。所以说多边形的顶点除了具有三维的空间坐标外。还具有二维的UV坐标。
简单使用
- 一个简单将物体一分为二的c#脚本
- EZSlice的原理其实是将物体的的节点和三角关系分割为切割面上下两个部分，与切割面相交的三角片做一个分割工作，然后将原始物体设为不可见，即可实现切割的动作。
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using EzySlice;
public class SlicerTest : MonoBehaviour
{
//要切割的物体为source
public GameObject BeCutThing;
// Update is called once per frame
void Update()
{
if (Input.GetKeyDown(KeyCode.D))
{
//将BeCutThing切割，传入的第一个参数为切割的位置（即刀片的位置），传入的第二个参数为切割面的法向量（即刀片表面的法向量）
SlicedHull hull = BeCutThing.Slice(transform.position, transform.up);
//创建把source切割以后的上半部分物体
hull.CreateUpperHull(BeCutThing);
//创建把source切割以后的下半部分物体
hull.CreateLowerHull(BeCutThing);
//由于新建切出来两个物体，因此要把原来的物体关闭
BeCutThing.SetActive(false);
}
}
}SlicedHull类
- 从切片操作生成的最终数据结构。这提供了方便的访问实用函数和最终的网格数据为每个部分的船体。主要是定义方法和步骤 具体实现和计算细节在其它类中
- 创建上片
public GameObject CreateUpperHull(GameObject original, Material crossSectionMat)//创建上、下片
public GameObject CreateLowerHull(GameObject original, Material crossSectionMat)//在层次结构中没有改变，横截面必须与子网格一起批处理，按原样返回，不需要任何改变
if (mesh.subMeshCount == upper_hull.subMeshCount) //subMesh：返回子网格的数量。每种材料都有一个单独的三角形列表
{
// the the material information
newObject.GetComponent<Renderer>().sharedMaterials = shared;
return newObject;
}- 创建空物体
private static GameObject CreateEmptyObject(string name, Mesh hull) //参数hull来自于上层物体的Mesh
{
if (hull == null) {
return null;
}
GameObject newObject = new GameObject(name);
//Mesh Filter是用了一个从资源里取到的mesh资源，然后通过Mesh Render，渲染到屏幕中
newObject.AddComponent<MeshRenderer>();//添加mesh渲染组件
MeshFilter filter = newObject.AddComponent<MeshFilter>();
filter.mesh = hull;
return newObject;
}Slicer类
- 切割的方法在这个类中！！
- crossSection：
/**
* 从一组交点和一个平面法线生成两个网格(上、下)截面
*/
private static List<Triangle> CreateFrom(List<Vector3> intPoints, Vector3 planeNormal, TextureRegion region) {
List<Triangle> tris;
if (Triangulator.MonotoneChain(intPoints, planeNormal, out tris, region)) {
return tris;
}//代码中切割部分！！！
/**
* 使用该平面切片gameobject mesh(如果有的话)，
* 它将生成最多2个其他网格。这个功能将重新计算新的UV坐标，
* 以确保纹理被正确应用。如果没有找到交集，
* 或者GameObject(游戏物体)不包含一个要切割的有效网格，则返回null。
*/
public static SlicedHull Slice(Mesh sharedMesh, Plane pl, TextureRegion region, int crossIndex) {
if (sharedMesh == null) {
return null;
}
Vector3[] verts = sharedMesh.vertices;//顶点
Vector2[] uv = sharedMesh.uv;//纹理
Vector3[] norm = sharedMesh.normals;//法向量
Vector4[] tan = sharedMesh.tangents;//获取物体的顶点切线
int submeshCount = sharedMesh.subMeshCount;//计算出共有多少个子网格
// 每个子网格将被切片并放置在它自己的数组结构中
SlicedSubmesh[] slices = new SlicedSubmesh[submeshCount];
// 船体的横截面（crossHull ）在所有的子网格中都是通用的
List<Vector3> crossHull = new List<Vector3>();
// 我们将此对象用于所有交集测试
IntersectionResult result = new IntersectionResult();
// 看看我们是否要分裂网格使用uv，法线和切线
bool genUV = verts.Length == uv.Length;
bool genNorm = verts.Length == norm.Length;
bool genTan = verts.Length == tan.Length;
// iterate over all（遍历所有） the submeshes individually. vertices and indices
// are all shared within the submesh
for (int submesh = 0; submesh < submeshCount; submesh++) {
int[] indices = sharedMesh.GetTriangles(submesh);
int indicesCount = indices.Length;
SlicedSubmesh mesh = new SlicedSubmesh();
// loop through all the mesh vertices, generating upper and lower hulls
// and all intersection points
for (int index = 0; index < indicesCount; index += 3) {
int i0 = indices[index + 0];
int i1 = indices[index + 1];
int i2 = indices[index + 2];
//**triangle()函数 用于初始化三角矩阵 除了顶点值外 全部赋值0
Triangle newTri = new Triangle(verts[i0], verts[i1], verts[i2]);
// generate UV if available
if (genUV) {
newTri.SetUV(uv[i0], uv[i1], uv[i2]);
}
// generate normals if available
if (genNorm) {
newTri.SetNormal(norm[i0], norm[i1], norm[i2]);
}
// generate tangents if available
if (genTan) {
newTri.SetTangent(tan[i0], tan[i1], tan[i2]);
}
// slice this particular triangle with the provided
// plane
if (newTri.Split(pl, result)) {
int upperHullCount = result.upperHullCount;
int lowerHullCount = result.lowerHullCount;
int interHullCount = result.intersectionPointCount;
for (int i = 0; i < upperHullCount; i++) {
mesh.upperHull.Add(result.upperHull[i]);
}
for (int i = 0; i < lowerHullCount; i++) {
mesh.lowerHull.Add(result.lowerHull[i]);
}
for (int i = 0; i < interHullCount; i++) {
crossHull.Add(result.intersectionPoints[i]);
}
} else {
SideOfPlane side = pl.SideOf(verts[i0]);
if (side == SideOfPlane.UP || side == SideOfPlane.ON) {
mesh.upperHull.Add(newTri);
} else {
mesh.lowerHull.Add(newTri);
}
}
}
// register into the index
slices[submesh] = mesh;
}
// check if slicing actually occured
for (int i = 0; i < slices.Length; i++) {
// check if at least one of the submeshes was sliced. If so, stop checking
// because we need to go through the generation step
if (slices[i] != null && slices[i].isValid) {
return CreateFrom(slices, CreateFrom(crossHull, pl.normal, region), crossIndex);
}
}
// no slicing occured, just return null to signify
return null;
}
/**
* Generates a single SlicedHull from a set of cut submeshes
*/
private static SlicedHull CreateFrom(SlicedSubmesh[] meshes, List<Triangle> cross, int crossSectionIndex)
{//Triangle依赖Framework文件夹
int submeshCount = meshes.Length;
int upperHullCount = 0;
int lowerHullCount = 0;
// get the total amount of upper, lower and intersection counts
for (int submesh = 0; submesh < submeshCount; submesh++) {
upperHullCount += meshes[submesh].upperHull.Count;
lowerHullCount += meshes[submesh].lowerHull.Count;
}
Mesh upperHull = CreateUpperHull(meshes, upperHullCount, cross, crossSectionIndex);
Mesh lowerHull = CreateLowerHull(meshes, lowerHullCount, cross, crossSectionIndex);
return new SlicedHull(upperHull, lowerHull);
}
private static Mesh CreateUpperHull(SlicedSubmesh[] mesh, int total, List<Triangle> crossSection, int crossSectionIndex) {
return CreateHull(mesh, total, crossSection, crossSectionIndex, true);
}
private static Mesh CreateLowerHull(SlicedSubmesh[] mesh, int total, List<Triangle> crossSection, int crossSectionIndex) {
return CreateHull(mesh, total, crossSection, crossSectionIndex, false);
}Intersector 类
- Intersect函数 共有两个重载
/**
* 执行平面p1与直线ab的交叉操作 有交点返回true 反之false
* 其中交叉点将存于vector3数组 q中（out型可直接被接收并使用）
*/
public static bool Intersect(Plane pl, Vector3 a, Vector3 b, out Vector3 q) {
Vector3 normal = pl.normal;
Vector3 ab = b - a;//得到ab直线所在向量
float t = (pl.dist - Vector3.Dot(normal, a)) / Vector3.Dot(normal, ab);
// need to be careful and compensate for floating errors
if (t >= -float.Epsilon && t <= (1 + float.Epsilon)) {
，
=
q = a + t * ab;
return true;
}
q = Vector3.zero;//结束时消除数据 全置0
return false;
}- //第二个Intersect函数 其中调用第一个Intersect函数
public static void Intersect(Plane pl, Triangle tri, IntersectionResult result) {
// clear the previous results from the IntersectionResult
result.Clear();
// grab local variables for easier access
//获取本地变量以方便访问
Vector3 a = tri.positionA;
Vector3 b = tri.positionB;
Vector3 c = tri.positionC;
/*
* 检查a点在平面的哪一边。SideOf操作是一个简单的点积和一些比较操作，所以这些是非常快速的检查
* check to see which side of the plane the points all
* lay in. SideOf operation is a simple dot product and some comparison
* operations, so these are a very quick checks
*/
SideOfPlane sa = pl.SideOf(a);//检查a点在平面的哪一边（三种结果 UP DOWN ON）
SideOfPlane sb = pl.SideOf(b);
SideOfPlane sc = pl.SideOf(c);
//其数学原理？？（待看）
// we cannot intersect if the triangle points all fall on the same side
// of the plane. This is an easy early out test as no intersections are possible.
if (sa == sb && sb == sc) {//均在同一侧 -->不切
return;
}
// detect cases where two points lay straight on the plane, meaning
// that the plane is actually parralel with one of the edges of the triangle
else if ((sa == SideOfPlane.ON && sa == sb) ||
(sa == SideOfPlane.ON && sa == sc) ||
(sb == SideOfPlane.ON && sb == sc))
{//一个点在平面上 其余两个点在同侧 -->不切
return;
}
/* keep in mind that intersection points are shared by both
* the upper HULL and lower HULL hence they lie perfectly
* on the plane that cut them
* 切割点/交点 正位于切割平面 且上下两个Hull共享它
*/
Vector3 qa;
Vector3 qb;
// check the cases where the points of the triangle actually lie on the plane itself
// in these cases, there is only going to be 2 triangles, one for the upper HULL and
// the other on the lower HULL
// we just need to figure out which points to accept into the upper or lower hulls.
//找出上下Hull中的点各是那些点！！（重要）-->对顶点分类
if (sa == SideOfPlane.ON) {
// if the point a is on the plane, test line b-c
if (Intersector.Intersect(pl, b, c, out qa))
{//调用上面Intersect的Intersect函数 -->若有交点则运行接下来的步骤 并将交点存储于qa
// line b-c intersected, construct out triangles and return approprietly
result.AddIntersectionPoint(qa);//加入数组（vector3类型）
result.AddIntersectionPoint(a);
// our two generated triangles, we need to figure out which
// triangle goes into the UPPER hull and which goes into the LOWER hull
Triangle ta = new Triangle(a, b, qa);//创建三角
Triangle tb = new Triangle(a, qa, c);
// generate UV coordinates if there is any
if (tri.hasUV) {
// the computed UV coordinate if the intersection point（交点）
Vector2 pq = tri.GenerateUV(qa);
Vector2 pa = tri.uvA;
Vector2 pb = tri.uvB;
Vector2 pc = tri.uvC;
ta.SetUV(pa, pb, pq);
tb.SetUV(pa, pq, pc);
}
// generate Normal coordinates if there is any
if (tri.hasNormal) {
// the computed Normal coordinate if the intersection point
Vector3 pq = tri.GenerateNormal(qa);
Vector3 pa = tri.normalA;
Vector3 pb = tri.normalB;
Vector3 pc = tri.normalC;
ta.SetNormal(pa, pb, pq);
tb.SetNormal(pa, pq, pc);
}
// generate Tangent coordinates if there is any
if (tri.hasTangent) {
// the computed Tangent coordinate if the intersection point
Vector4 pq = tri.GenerateTangent(qa);
Vector4 pa = tri.tangentA;
Vector4 pb = tri.tangentB;
Vector4 pc = tri.tangentC;
ta.SetTangent(pa, pb, pq);
tb.SetTangent(pa, pq, pc);
}
// b point lies on the upside of the plane
if (sb == SideOfPlane.UP) {
result.AddUpperHull(ta).AddLowerHull(tb);
}
// b point lies on the downside of the plane
else if (sb == SideOfPlane.DOWN) {
result.AddUpperHull(tb).AddLowerHull(ta);
}
}
}
// test the case where the b point lies on the plane itself
else if (sb == SideOfPlane.ON) {
// if the point b is on the plane, test line a-c
if (Intersector.Intersect(pl, a, c, out qa)) {
// line a-c intersected, construct out triangles and return approprietly
result.AddIntersectionPoint(qa);
result.AddIntersectionPoint(b);
// our two generated triangles, we need to figure out which
// triangle goes into the UPPER hull and which goes into the LOWER hull
Triangle ta = new Triangle(a, b, qa);
Triangle tb = new Triangle(qa, b, c);
// generate UV coordinates if there is any
if (tri.hasUV) {
// the computed UV coordinate if the intersection point
Vector2 pq = tri.GenerateUV(qa);
Vector2 pa = tri.uvA;
Vector2 pb = tri.uvB;
Vector2 pc = tri.uvC;
ta.SetUV(pa, pb, pq);
tb.SetUV(pq, pb, pc);
}
// generate Normal coordinates if there is any
if (tri.hasNormal) {
// the computed Normal coordinate if the intersection point
Vector3 pq = tri.GenerateNormal(qa);
Vector3 pa = tri.normalA;
Vector3 pb = tri.normalB;
Vector3 pc = tri.normalC;
ta.SetNormal(pa, pb, pq);
tb.SetNormal(pq, pb, pc);
}
// generate Tangent coordinates if there is any
if (tri.hasTangent) {
// the computed Tangent coordinate if the intersection point
Vector4 pq = tri.GenerateTangent(qa);
Vector4 pa = tri.tangentA;
Vector4 pb = tri.tangentB;
Vector4 pc = tri.tangentC;
ta.SetTangent(pa, pb, pq);
tb.SetTangent(pq, pb, pc);
}
// a point lies on the upside of the plane
if (sa == SideOfPlane.UP) {
result.AddUpperHull(ta).AddLowerHull(tb);
}
// a point lies on the downside of the plane
else if (sa == SideOfPlane.DOWN) {
result.AddUpperHull(tb).AddLowerHull(ta);
}
}
}
// test the case where the c point lies on the plane itself
else if (sc == SideOfPlane.ON) {
// if the point c is on the plane, test line a-b
if (Intersector.Intersect(pl, a, b, out qa)) {
// line a-c intersected, construct out triangles and return approprietly
result.AddIntersectionPoint(qa);
result.AddIntersectionPoint(c);
// our two generated triangles, we need to figure out which
// triangle goes into the UPPER hull and which goes into the LOWER hull
Triangle ta = new Triangle(a, qa, c);
Triangle tb = new Triangle(qa, b, c);
// generate UV coordinates if there is any
if (tri.hasUV) {
// the computed UV coordinate if the intersection point
Vector2 pq = tri.GenerateUV(qa);
Vector2 pa = tri.uvA;
Vector2 pb = tri.uvB;
Vector2 pc = tri.uvC;
ta.SetUV(pa, pq, pc);
tb.SetUV(pq, pb, pc);
}
// generate Normal coordinates if there is any
if (tri.hasNormal) {
// the computed Normal coordinate if the intersection point
Vector3 pq = tri.GenerateNormal(qa);
Vector3 pa = tri.normalA;
Vector3 pb = tri.normalB;
Vector3 pc = tri.normalC;
ta.SetNormal(pa, pq, pc);
tb.SetNormal(pq, pb, pc);
}
// generate Tangent coordinates if there is any
if (tri.hasTangent) {
// the computed Tangent coordinate if the intersection point
Vector4 pq = tri.GenerateTangent(qa);
Vector4 pa = tri.tangentA;
Vector4 pb = tri.tangentB;
Vector4 pc = tri.tangentC;
ta.SetTangent(pa, pq, pc);
tb.SetTangent(pq, pb, pc);
}
// a point lies on the upside of the plane
if (sa == SideOfPlane.UP) {
result.AddUpperHull(ta).AddLowerHull(tb);
}
// a point lies on the downside of the plane
else if (sa == SideOfPlane.DOWN) {
result.AddUpperHull(tb).AddLowerHull(ta);
}
}
}
// at this point, all edge cases have been tested and failed, we need to perform
// full intersection tests against the lines. From this point onwards we will generate
// 3 triangles
else if (sa != sb && Intersector.Intersect(pl, a, b, out qa)) {
// intersection found against a - b
result.AddIntersectionPoint(qa);
// since intersection was found against a - b, we need to check which other
// lines to check (we only need to check one more line) for intersection.
// the line we check against will be the line against the point which lies on
// the other side of the plane.
if (sa == sc) {
// we likely have an intersection against line b-c which will complete this loop
if (Intersector.Intersect(pl, b, c, out qb)) {
result.AddIntersectionPoint(qb);
// our three generated triangles. Two of these triangles will end
// up on either the UPPER or LOWER hulls.
Triangle ta = new Triangle(qa, b, qb);
Triangle tb = new Triangle(a, qa, qb);
Triangle tc = new Triangle(a, qb, c);
// generate UV coordinates if there is any
if (tri.hasUV) {
// the computed UV coordinate if the intersection point
Vector2 pqa = tri.GenerateUV(qa);
Vector2 pqb = tri.GenerateUV(qb);
Vector2 pa = tri.uvA;
Vector2 pb = tri.uvB;
Vector2 pc = tri.uvC;
ta.SetUV(pqa, pb, pqb);
tb.SetUV(pa, pqa, pqb);
tc.SetUV(pa, pqb, pc);
}
// generate Normal coordinates if there is any
if (tri.hasNormal) {
// the computed Normal coordinate if the intersection point
Vector3 pqa = tri.GenerateNormal(qa);
Vector3 pqb = tri.GenerateNormal(qb);
Vector3 pa = tri.normalA;
Vector3 pb = tri.normalB;
Vector3 pc = tri.normalC;
ta.SetNormal(pqa, pb, pqb);
tb.SetNormal(pa, pqa, pqb);
tc.SetNormal(pa, pqb, pc);
}
// generate Tangent coordinates if there is any
if (tri.hasTangent) {
// the computed Tangent coordinate if the intersection point
Vector4 pqa = tri.GenerateTangent(qa);
Vector4 pqb = tri.GenerateTangent(qb);
Vector4 pa = tri.tangentA;
Vector4 pb = tri.tangentB;
Vector4 pc = tri.tangentC;
ta.SetTangent(pqa, pb, pqb);
tb.SetTangent(pa, pqa, pqb);
tc.SetTangent(pa, pqb, pc);
}
if (sa == SideOfPlane.UP) {
result.AddUpperHull(tb).AddUpperHull(tc).AddLowerHull(ta);
} else {
result.AddLowerHull(tb).AddLowerHull(tc).AddUpperHull(ta);
}
}
} else {
// in this scenario, the point a is a "lone" point which lies in either upper
// or lower HULL. We need to perform another intersection to find the last point
if (Intersector.Intersect(pl, a, c, out qb)) {
result.AddIntersectionPoint(qb);
// our three generated triangles. Two of these triangles will end
// up on either the UPPER or LOWER hulls.
Triangle ta = new Triangle(a, qa, qb);
Triangle tb = new Triangle(qa, b, c);
Triangle tc = new Triangle(qb, qa, c);
// generate UV coordinates if there is any
if (tri.hasUV) {
// the computed UV coordinate if the intersection point
Vector2 pqa = tri.GenerateUV(qa);
Vector2 pqb = tri.GenerateUV(qb);
Vector2 pa = tri.uvA;
Vector2 pb = tri.uvB;
Vector2 pc = tri.uvC;
ta.SetUV(pa, pqa, pqb);
tb.SetUV(pqa, pb, pc);
tc.SetUV(pqb, pqa, pc);
}
// generate Normal coordinates if there is any
if (tri.hasNormal) {
// the computed Normal coordinate if the intersection point
Vector3 pqa = tri.GenerateNormal(qa);
Vector3 pqb = tri.GenerateNormal(qb);
Vector3 pa = tri.normalA;
Vector3 pb = tri.normalB;
Vector3 pc = tri.normalC;
ta.SetNormal(pa, pqa, pqb);
tb.SetNormal(pqa, pb, pc);
tc.SetNormal(pqb, pqa, pc);
}
// generate Tangent coordinates if there is any
if (tri.hasTangent) {
// the computed Tangent coordinate if the intersection point
Vector4 pqa = tri.GenerateTangent(qa);
Vector4 pqb = tri.GenerateTangent(qb);
Vector4 pa = tri.tangentA;
Vector4 pb = tri.tangentB;
Vector4 pc = tri.tangentC;
ta.SetTangent(pa, pqa, pqb);
tb.SetTangent(pqa, pb, pc);
tc.SetTangent(pqb, pqa, pc);
}
if (sa == SideOfPlane.UP) {
result.AddUpperHull(ta).AddLowerHull(tb).AddLowerHull(tc);
} else {
result.AddLowerHull(ta).AddUpperHull(tb).AddUpperHull(tc);
}
}
}
}
// if line a-b did not intersect (or the lie on the same side of the plane)
// this simplifies the problem a fair bit. This means we have an intersection
// in line a-c and b-c, which we can use to build a new UPPER and LOWER hulls
// we are expecting both of these intersection tests to pass, otherwise something
// went wrong (float errors? missed a checked case?)
else if (Intersector.Intersect(pl, c, a, out qa) && Intersector.Intersect(pl, c, b, out qb)) {
// in here we know that line a-b actually lie on the same side of the plane, this will
// simplify the rest of the logic. We also have our intersection points
// the computed UV coordinate of the intersection point
result.AddIntersectionPoint(qa);
result.AddIntersectionPoint(qb);
// our three generated triangles. Two of these triangles will end
// up on either the UPPER or LOWER hulls.
Triangle ta = new Triangle(qa, qb, c);
Triangle tb = new Triangle(a, qb, qa);
Triangle tc = new Triangle(a, b, qb);
// generate UV coordinates if there is any
if (tri.hasUV) {
// the computed UV coordinate if the intersection point
Vector2 pqa = tri.GenerateUV(qa);
Vector2 pqb = tri.GenerateUV(qb);
Vector2 pa = tri.uvA;
Vector2 pb = tri.uvB;
Vector2 pc = tri.uvC;
ta.SetUV(pqa, pqb, pc);
tb.SetUV(pa, pqb, pqa);
tc.SetUV(pa, pb, pqb);
}
// generate Normal coordinates if there is any
if (tri.hasNormal) {
// the computed Normal coordinate if the intersection point
Vector3 pqa = tri.GenerateNormal(qa);
Vector3 pqb = tri.GenerateNormal(qb);
Vector3 pa = tri.normalA;
Vector3 pb = tri.normalB;
Vector3 pc = tri.normalC;
ta.SetNormal(pqa, pqb, pc);
tb.SetNormal(pa, pqb, pqa);
tc.SetNormal(pa, pb, pqb);
}
// generate Tangent coordinates if there is any
if (tri.hasTangent) {
// the computed Tangent coordinate if the intersection point
Vector4 pqa = tri.GenerateTangent(qa);
Vector4 pqb = tri.GenerateTangent(qb);
Vector4 pa = tri.tangentA;
Vector4 pb = tri.tangentB;
Vector4 pc = tri.tangentC;
ta.SetTangent(pqa, pqb, pc);
tb.SetTangent(pa, pqb, pqa);
tc.SetTangent(pa, pb, pqb);
}
if (sa == SideOfPlane.UP) {
result.AddUpperHull(tb).AddUpperHull(tc).AddLowerHull(ta);
} else {
result.AddLowerHull(tb).AddLowerHull(tc).AddUpperHull(ta);
}
}
}
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