public List <TriangleGroup> TriangleGroups = new List <TriangleGroup>(); // 面
public float Intersect(Ray ray, ref TriangleGroup interTG, ref Vector3 normal, ref Color4 color)
{
float interT = float.PositiveInfinity;
Vector3 nNormal = Vector3.zero;
Color4 nColor = Color4.zero;
foreach (var tg in TriangleGroups)
{
float t = tg.Intersect(ray, ref nNormal, ref nColor);
if (t > 0.0001f && t < interT)
{
interTG = tg;
interT = t;
normal = nNormal;
color = nColor;
}
}
if (interT == float.PositiveInfinity)
{
return(-1);
}
return(interT);
}
public static Mesh LoadFromObj(string fileName)
{
using (var sr = new StreamReader(new FileStream(fileName, FileMode.Open))) {
Mesh mesh = new Mesh();
Dictionary <string, Material> ms = null;
List <Vector3> vs = new List <Vector3>(); // 顶点
List <Vector3> ns = new List <Vector3>(); // 法线
List <Vector2> ts = new List <Vector2>(); // 纹理坐标
TriangleGroup triangleGroup = null;
int i = 0;
while (!sr.EndOfStream)
{
string line = sr.ReadLine();
i++;
try {
if (line.StartsWith("#"))
{
continue;
}
if (line.StartsWith("vn"))
{
ReadLine(ns, line);
}
else if (line.StartsWith("vt"))
{
ReadLine(ts, line);
}
else if (line.StartsWith("v"))
{
ReadLine(vs, line);
}
else if (line.StartsWith("o"))
{
string[] data = line.Split(' ');
if (data.Length != 2)
{
throw new Exception($"第{i}行，OBJ格式错误");
}
if (triangleGroup != null)
{
triangleGroup.GenerateAABB();
mesh.TriangleGroups.Add(triangleGroup);
}
triangleGroup = new TriangleGroup(data[1]);
}
else if (line.StartsWith("f"))
{
Triangle triangle = ReadLine(vs, ns, ts, line);
triangleGroup.Triangles.Add(triangle);
}
else if (line.StartsWith("mtllib"))
{
string[] data = line.Split(' ');
if (data.Length != 2)
{
throw new Exception($"第{i}行，OBJ格式错误");
}
ms = Material.LoadFromMtl(Path.Combine(Path.GetDirectoryName(fileName), data[1]));
}
else if (line.StartsWith("usemtl"))
{
string[] data = line.Split(' ');
if (data.Length != 2)
{
throw new Exception($"第{i}行，OBJ格式错误");
}
if (ms == null)
{
throw new Exception($"第{i}行，材质未加载");
}
triangleGroup.Material = ms[data[1]];
}
} catch (Exception e) {
throw new Exception($"第{i}行", e);
}
}
if (triangleGroup == null)
{
throw new Exception("OBJ格式错误，没有物体");
}
triangleGroup.GenerateAABB();
mesh.TriangleGroups.Add(triangleGroup);
return(mesh);
}
}
