public SoftwareImage <T>[] Generate(int newSize, int nSample)
{
var faces = new SoftwareImage <T> [6];
faces[0] = new SoftwareImage <T>(newSize, newSize, _image.PixelTransformer);
faces[1] = new SoftwareImage <T>(newSize, newSize, _image.PixelTransformer);
faces[2] = new SoftwareImage <T>(newSize, newSize, _image.PixelTransformer);
faces[3] = new SoftwareImage <T>(newSize, newSize, _image.PixelTransformer);
faces[4] = new SoftwareImage <T>(newSize, newSize, _image.PixelTransformer);
faces[5] = new SoftwareImage <T>(newSize, newSize, _image.PixelTransformer);
var p = faces[0].PixelTransformer;
var rand = new Random();
for (int z = 0; z < 6; ++z)
{
for (int y = 0; y < newSize; ++y)
{
for (int x = 0; x < newSize; ++x)
{
var center = SkyboxHelper.CubeToDir(newSize, x, y, z);
center = Vector3.Normalize(center);
var sampler = new SphereDirectionalSampler(rand, center, (float)Math.PI / 2, nSample);
T total = default;
for (int sample = 0; sample < sampler.SampleCount; ++sample)
{
var sampleDir = sampler.Sample(sample);
var color = SkyboxHelper.SampleEquirectangularMap(_image, sampleDir);
total = p.Add(total, p.Scale(color, Vector3.Dot(center, sampleDir)));
}
faces[z].GetPixel(x, y) = p.Scale(total, 1f / sampler.SampleCount / (float)Math.PI);
}
}
}
return(faces);
}
static void Main(string[] args)
{
var normalMap = new SoftwareImage <R32G32B32A32F>(800, 600, new R32G32B32A32FTransformer());
normalMap.LoadRawDataFile(TestSceneCompiled("OutputNormal.raw"));
var viewDirMap = new SoftwareImage <R32G32B32A32F>(800, 600, new R32G32B32A32FTransformer());
viewDirMap.LoadRawDataFile(TestSceneCompiled("OutputViewDir.raw"));
SoftwareImage <R32G32B32A32F> skybox = HdrImageLoader.Read(TestSceneResource("473-free-hdri-skies-com.hdr"));
SoftwareImage <R32G32B32A32F> skyboxSpecular = skybox;
{
skyboxSpecular = new HalfSize <R32G32B32A32F>(skyboxSpecular).Generate();
skyboxSpecular = new HalfSize <R32G32B32A32F>(skyboxSpecular).Generate();
skyboxSpecular = new HalfSize <R32G32B32A32F>(skyboxSpecular).Generate();
skyboxSpecular = new HalfSize <R32G32B32A32F>(skyboxSpecular).Generate();
skyboxSpecular = new HalfSize <R32G32B32A32F>(skyboxSpecular).Generate();
}
SoftwareImage <R32G32B32A32F> skyboxDiffuse = skybox;
{
skyboxDiffuse = new HalfSize <R32G32B32A32F>(skyboxDiffuse).Generate();
skyboxDiffuse = new HalfSize <R32G32B32A32F>(skyboxDiffuse).Generate();
skyboxDiffuse = new HalfSize <R32G32B32A32F>(skyboxDiffuse).Generate();
skyboxDiffuse = new HalfSize <R32G32B32A32F>(skyboxDiffuse).Generate();
skyboxDiffuse = new HalfSize <R32G32B32A32F>(skyboxDiffuse).Generate();
skyboxDiffuse = new HalfSize <R32G32B32A32F>(skyboxDiffuse).Generate();
skyboxDiffuse = new HalfSize <R32G32B32A32F>(skyboxDiffuse).Generate();
}
var p = skybox.PixelTransformer;
//System.Drawing.Bitmap does not support concurrent SetPixel. Use our own instead.
var bitmap = new SoftwareImage <R8G8B8A8>(800, 600, new R8G8B8A8Transformer());
Parallel.For(0, 600, (int y) =>
{
var rand = _rand.Value;
for (int x = 0; x < 800; ++x)
{
var normal = normalMap.GetPixel(x, y);
if (normal.R == 0 && normal.G == 0 && normal.B == 0)
{
continue;
}
var viewDir = viewDirMap.GetPixel(x, y);
var n = new Vector3(normal.R, normal.G, normal.B);
var e = Vector3.Normalize(-new Vector3(viewDir.R, viewDir.G, viewDir.B));
var l = Vector3.Normalize(2 * Vector3.Dot(n, e) * n - e);
R32G32B32A32F color = default;
//Specular
{
//color = p.Add(color, SkyboxHelper.SampleEquirectangularMap(skyboxSpecular, l));
const int SpecularSampleCount = 40;
var sampler = new SphereDirectionalSampler(rand, l, (float)Math.PI / 2, SpecularSampleCount);
R32G32B32A32F total = default;
for (int sample = 0; sample < sampler.SampleCount; ++sample)
{
var sampleDir = sampler.Sample(sample);
if (Vector3.Dot(sampleDir, n) < 0)
{
continue;
}
var cc = SkyboxHelper.SampleEquirectangularMap(skyboxSpecular, sampleDir);
total = p.Add(total, p.Scale(cc, Vector3.Dot(n, sampleDir) * (float)BRDF(n, sampleDir, e)));
}
color = p.Add(color, p.Scale(total, 1f / sampler.SampleCount * 5));
}
//Diffuse
{
const int DiffuseSampleCount = 10;
var sampler = new SphereDirectionalSampler(rand, n, (float)Math.PI / 2, DiffuseSampleCount);
R32G32B32A32F total = default;
for (int sample = 0; sample < sampler.SampleCount; ++sample)
{
var sampleDir = sampler.Sample(sample);
var cc = SkyboxHelper.SampleEquirectangularMap(skyboxDiffuse, sampleDir);
total = p.Add(total, p.Scale(cc, Vector3.Dot(n, sampleDir) / (float)Math.PI));
}
color = p.Add(color, p.Scale(total, 1f / sampler.SampleCount * 0));
}
var rgb = p.ToColor(color);
bitmap.GetPixel(x, y) = new R8G8B8A8
{
R = rgb.R,
G = rgb.G,
B = rgb.B,
A = 255,
};
}
//}
});
bitmap.ToBitmap().Save(TestSceneCompiled("Offline.png"));
}
