protected override async Task LoadContent()
{
await base.LoadContent();
cubemapSpriteEffect = EffectSystem.LoadEffect("CubemapSprite").WaitForResult();
drawEffectContext = RenderContext.GetShared(Services);
lamberFilter = new LambertianPrefilteringSH(drawEffectContext);
renderSHEffect = new SphericalHarmonicsRendererEffect();
renderSHEffect.Initialize(drawEffectContext);
spriteBatch = new SpriteBatch(GraphicsDevice);
inputCubemap = Asset.Load<Texture>("CubeMap");
outputCubemap = Texture.NewCube(GraphicsDevice, 256, 1, PixelFormat.R8G8B8A8_UNorm, TextureFlags.RenderTarget | TextureFlags.ShaderResource).DisposeBy(this);
displayedCubemap = outputCubemap;
}
public static SkyboxResult Compile(SkyboxAsset asset, SkyboxGeneratorContext context)
{
if (asset == null) throw new ArgumentNullException("asset");
if (context == null) throw new ArgumentNullException("context");
var result = new SkyboxResult { Skybox = new Skybox() };
var parameters = context.Parameters;
var skybox = result.Skybox;
skybox.Parameters = parameters;
if (asset.Model != null)
{
var cubemap = ((SkyboxCubeMapModel)asset.Model).CubeMap;
if (cubemap == null)
{
return result;
}
// load the skybox texture from the asset.
var reference = AttachedReferenceManager.GetAttachedReference(cubemap);
var skyboxTexture = context.Assets.Load<Texture>(BuildTextureForSkyboxGenerationLocation(reference.Url));
if (skyboxTexture.Dimension != TextureDimension.TextureCube)
{
result.Error("SkyboxGenerator: The texture used as skybox should be a Cubemap.");
return result;
}
var shaderSource = asset.Model.Generate(context);
parameters.Set(SkyboxKeys.Shader, shaderSource);
// -------------------------------------------------------------------
// Calculate Diffuse prefiltering
// -------------------------------------------------------------------
var lamberFiltering = new LambertianPrefilteringSH(context.DrawEffectContext);
lamberFiltering.HarmonicOrder = (int)asset.DiffuseSHOrder;
lamberFiltering.RadianceMap = skyboxTexture;
lamberFiltering.Draw();
var coefficients = lamberFiltering.PrefilteredLambertianSH.Coefficients;
// TODO: MOVE THE COEFFICIENTS TO THE SphericalHarmonics type in Core.Mathematics
var PI4 = 4 * Math.PI;
var PI16 = 16 * Math.PI;
var PI64 = 64 * Math.PI;
var SQRT_PI = 1.77245385090551602729;
var bases = new float[coefficients.Length];
bases[0] = (float)(1.0 / (2.0 * SQRT_PI));
bases[1] = (float)(-Math.Sqrt(3.0 / PI4));
bases[2] = (float)(Math.Sqrt(3.0 / PI4));
bases[3] = (float)(-Math.Sqrt(3.0 / PI4));
bases[4] = (float)(Math.Sqrt(15.0 / PI4));
bases[5] = (float)(-Math.Sqrt(15.0 / PI4));
bases[6] = (float)(Math.Sqrt(5.0 / PI16));
bases[7] = (float)(-Math.Sqrt(15.0 / PI4));
bases[8] = (float)(Math.Sqrt(15.0 / PI16));
if (asset.DiffuseSHOrder == SkyboxPreFilteringDiffuseOrder.Order5)
{
bases[9] = -(float)Math.Sqrt(7 / PI64);
bases[10] = (float)Math.Sqrt(105 / PI4);
bases[11] = -(float)Math.Sqrt(21 / PI16);
bases[12] = (float)Math.Sqrt(7 / PI16);
bases[13] = -(float)Math.Sqrt(42 / PI64);
bases[14] = (float)Math.Sqrt(105 / PI16);
bases[15] = -(float)Math.Sqrt(70 / PI64);
bases[16] = 3 * (float)Math.Sqrt(35 / PI16);
bases[17] = -3 * (float)Math.Sqrt(70 / PI64);
bases[18] = 3 * (float)Math.Sqrt(5 / PI16);
bases[19] = -3 * (float)Math.Sqrt(10 / PI64);
bases[20] = (float)(1.0 / (16.0 * SQRT_PI));
bases[21] = -3 * (float)Math.Sqrt(10 / PI64);
bases[22] = 3 * (float)Math.Sqrt(5 / PI64);
bases[23] = -3 * (float)Math.Sqrt(70 / PI64);
bases[24] = 3 * (float)Math.Sqrt(35 / (4 * PI64));
}
for (int i = 0; i < coefficients.Length; i++)
{
coefficients[i] = coefficients[i] * bases[i];
}
skybox.DiffuseLightingParameters.Set(SkyboxKeys.Shader, new ShaderClassSource("SphericalHarmonicsEnvironmentColor", lamberFiltering.HarmonicOrder));
skybox.DiffuseLightingParameters.Set(SphericalHarmonicsEnvironmentColorKeys.SphericalColors, coefficients);
// -------------------------------------------------------------------
// Calculate Specular prefiltering
// -------------------------------------------------------------------
var specularRadiancePrefilterGGX = new RadiancePrefilteringGGX(context.DrawEffectContext);
var textureSize = asset.SpecularCubeMapSize <= 0 ? 64 : asset.SpecularCubeMapSize;
textureSize = (int)Math.Pow(2, Math.Round(Math.Log(textureSize, 2)));
if (textureSize < 64) textureSize = 64;
// TODO: Add support for HDR 32bits
var filteringTextureFormat = skyboxTexture.Format.IsHDR() ? skyboxTexture.Format : PixelFormat.R8G8B8A8_UNorm;
//var outputTexture = Texture.New2D(graphicsDevice, 256, 256, skyboxTexture.Format, TextureFlags.ShaderResource | TextureFlags.UnorderedAccess, 6);
using (var outputTexture = Texture.New2D(context.GraphicsDevice, textureSize, textureSize, true, filteringTextureFormat, TextureFlags.ShaderResource | TextureFlags.UnorderedAccess, 6))
{
specularRadiancePrefilterGGX.RadianceMap = skyboxTexture;
specularRadiancePrefilterGGX.PrefilteredRadiance = outputTexture;
specularRadiancePrefilterGGX.Draw();
var cubeTexture = Texture.NewCube(context.GraphicsDevice, textureSize, true, skyboxTexture.Format);
context.GraphicsDevice.Copy(outputTexture, cubeTexture);
cubeTexture.SetSerializationData(cubeTexture.GetDataAsImage());
skybox.SpecularLightingParameters.Set(SkyboxKeys.Shader, new ShaderClassSource("RoughnessCubeMapEnvironmentColor"));
skybox.SpecularLightingParameters.Set(SkyboxKeys.CubeMap, cubeTexture);
}
// TODO: cubeTexture is not deallocated
}
return result;
}