public static SimpleMesh Import(string path, bool swapYZ)
{
long fileByteSize = new System.IO.FileInfo(path).Length;
// would use Allocator.Temp, but that doesn't clean up on re-allocation; so total RAM balloons
NativeArrayList <float3> positionsLUT = new NativeArrayList <float3>(1024 * 64, Allocator.Persistent);
NativeArrayList <Color32> colorsLUT = new NativeArrayList <Color32>(1024 * 64, Allocator.Persistent);
NativeArrayList <float2> uvLookupTable = new NativeArrayList <float2>(1024 * 64, Allocator.Persistent);
NativeArrayList <SimpleMesh.Vertex> vertexResult = new NativeArrayList <SimpleMesh.Vertex>(1024 * 64, Allocator.Persistent);
SimpleMesh.MaterialLib activeMaterialLib = default;
SimpleMesh.Material activeMaterial = default;
char[] splits = new char[] { ' ' };
Profiler.BeginSample("Read file");
using (var file = new System.IO.FileStream(path, System.IO.FileMode.Open, System.IO.FileAccess.Read)) {
using (var text = new System.IO.StreamReader(file)) {
while (true)
{
if (text.EndOfStream)
{
break;
}
string line = text.ReadLine();
if (line == null || line.Length == 0)
{
continue;
}
// start of a line
if (line.StartsWith("v "))
{
ParsePositionLine();
}
else if (line.StartsWith("f "))
{
ParseFaceLine();
}
else if (line.StartsWith("vt "))
{
ParseUVLine();
}
else if (line.StartsWith("vn "))
{
//
}
else if (line.StartsWith("mtllib "))
{
activeMaterialLib = SimpleMesh.MaterialLib.ParseFromObj(path, line.Substring("mtllib ".Length));
}
else if (line.StartsWith("o "))
{
//
}
else if (line.StartsWith("usemtl "))
{
activeMaterial = activeMaterialLib.GetByName(line.Substring("usemtl ".Length));
}
continue;
void ParseUVLine()
{
string[] subs = line.Split(splits, System.StringSplitOptions.RemoveEmptyEntries);
float2 uv = new float2(ParseFloat(subs[1]), ParseFloat(subs[2]));
uvLookupTable.Add(uv);
}
void ParsePositionLine()
{
string[] subs = line.Split(splits, System.StringSplitOptions.RemoveEmptyEntries);
float3 pos = new float3(ParseFloat(subs[1]), ParseFloat(subs[2]), ParseFloat(subs[3]));
if (swapYZ)
{
float t = pos.z;
pos.z = pos.y;
pos.y = t;
}
positionsLUT.Add(pos);
Color color;
if (subs.Length > 6)
{
color.r = ParseFloat(subs[4]);
color.g = ParseFloat(subs[5]);
color.b = ParseFloat(subs[6]);
color.a = 1f;
}
else
{
color = Color.white;
}
colorsLUT.Add(color);
}
float ParseFloat(string str)
{
return(float.Parse(str, System.Globalization.CultureInfo.InvariantCulture));
}
void ParseFaceLine()
{
int index = 2;
int entriesPerIndex = 1;
for (int i = index; i < line.Length && line[i] != ' '; i++)
{
if (line[i] == '/')
{
entriesPerIndex++;
}
}
switch (entriesPerIndex)
{
case 1: // f v1 v2 v3
for (int i = 0; i < 3; i++)
{
vertexResult.Add(GatherVertex(ParseFaceIndex(line, ref index), -1, -1));
index++;
}
break;
case 2: // f v1/vt1 v2/vt2 v3/vt3
for (int i = 0; i < 3; i++)
{
int v = ParseFaceIndex(line, ref index);
index++; // skip /
int vt = ParseFaceIndex(line, ref index);
index++; // skip space between the 3 indices
vertexResult.Add(GatherVertex(v, vt, -1));
}
break;
case 3:
// f v1/vt1/vn1 ..
// f v1//vn1 ..
for (int i = 0; i < 3; i++)
{
int v = ParseFaceIndex(line, ref index);
index++; // skip /
int vt = -1;
if (line[index] != '/')
{
// vt1
vt = ParseFaceIndex(line, ref index);
}
index++; // skip second /
int vn = ParseFaceIndex(line, ref index);
index++; // skip space between the 3 indices
vertexResult.Add(GatherVertex(v, vt, vn));
}
break;
}
}
SimpleMesh.Vertex GatherVertex(int positionIndex, int textureIndex, int normalIndex)
{
SimpleMesh.Vertex vertex = default;
vertex.Color = colorsLUT[positionIndex];
vertex.Position = positionsLUT[positionIndex];
if (textureIndex >= 0)
{
vertex.UV = uvLookupTable[textureIndex];
}
vertex.MaterialIndex = activeMaterial?.MaterialIndex ?? -1;
return(vertex);
}
}
}
}
positionsLUT.Dispose();
uvLookupTable.Dispose();
colorsLUT.Dispose();
Profiler.EndSample();
int vertexCount = vertexResult.Count;
unsafe {
SimpleMesh.Vertex *vertices = (SimpleMesh.Vertex *)SimpleMesh.MallocHelper <SimpleMesh.Vertex>(vertexCount);
UnsafeUtility.MemCpy(vertices, vertexResult.Array.GetUnsafePtr(), UnsafeUtility.SizeOf <SimpleMesh.Vertex>() * vertexCount);
vertexResult.Dispose();
int *indices = (int *)SimpleMesh.MallocHelper <int>(vertexCount);
for (int i = 0; i < vertexCount; i++)
{
indices[i] = i;
}
return(new SimpleMesh(activeMaterialLib, vertices, indices, vertexCount, vertexCount));
}
}