public static void ComplexScene(int numTrials)
{
// the scene is compressed to avoid git issues
if (!File.Exists("../Data/breakfast_room.obj"))
{
ZipFile.ExtractToDirectory("../Data/breakfast_room.zip", "../Data");
}
Stopwatch stop = Stopwatch.StartNew();
List <TriangleMesh> meshes = new();
Vector3 min = Vector3.One * float.MaxValue;
Vector3 max = -Vector3.One * float.MaxValue;
Assimp.AssimpContext context = new();
var scene = context.ImportFile("../Data/breakfast_room.obj",
Assimp.PostProcessSteps.GenerateNormals | Assimp.PostProcessSteps.JoinIdenticalVertices |
Assimp.PostProcessSteps.PreTransformVertices | Assimp.PostProcessSteps.Triangulate);
foreach (var m in scene.Meshes)
{
var material = scene.Materials[m.MaterialIndex];
string materialName = material.Name;
Vector3[] vertices = new Vector3[m.VertexCount];
for (int i = 0; i < m.VertexCount; ++i)
{
vertices[i] = new(m.Vertices[i].X, m.Vertices[i].Y, m.Vertices[i].Z);
}
meshes.Add(new(vertices, m.GetIndices()));
min.X = MathF.Min(min.X, m.BoundingBox.Min.X);
min.Y = MathF.Min(min.X, m.BoundingBox.Min.Y);
min.Z = MathF.Min(min.X, m.BoundingBox.Min.Z);
max.X = MathF.Max(max.X, m.BoundingBox.Max.X);
max.Y = MathF.Max(max.X, m.BoundingBox.Max.Y);
max.Z = MathF.Max(max.X, m.BoundingBox.Max.Z);
}
var diagonal = max - min;
Console.WriteLine($"Scene loaded in {stop.ElapsedMilliseconds}ms");
stop.Restart();
var rt = new Raytracer();
foreach (var m in meshes)
{
rt.AddMesh(m);
}
rt.CommitScene();
Console.WriteLine($"Acceleration structures built in {stop.ElapsedMilliseconds}ms");
Random rng = new(1337);
Vector3 NextVector() => new Vector3(
(float)rng.NextDouble(),
(float)rng.NextDouble(),
(float)rng.NextDouble());
stop.Restart();
float averageDistance = 0;
for (int k = 0; k < numTrials; ++k)
{
for (int i = 0; i < 1000000; ++i)
{
var hit = rt.Trace(new Ray {
Origin = NextVector() * diagonal + min,
Direction = NextVector(),
MinDistance = 0.0f
});
if (hit)
{
averageDistance += hit.Distance / 1000000 / numTrials;
}
}
}
stop.Stop();
Console.WriteLine($"One million closest hits found in {stop.ElapsedMilliseconds / numTrials}ms");
Console.WriteLine($"Average distance: {averageDistance}");
stop.Restart();
float averageVisibility = 0;
for (int k = 0; k < numTrials; ++k)
{
for (int i = 0; i < 1000000; ++i)
{
bool occluded = rt.IsOccluded(new ShadowRay(new Ray {
Origin = NextVector() * diagonal + min,
Direction = NextVector(),
MinDistance = 0.0f
}, maxDistance: (float)rng.NextDouble() * averageDistance * 5));
if (!occluded)
{
averageVisibility += 1.0f / 1000000.0f / numTrials;
}
}
}
stop.Stop();
Console.WriteLine($"One million any hits found in {stop.ElapsedMilliseconds / numTrials}ms");
Console.WriteLine($"Average visibility: {averageVisibility}");
}
