/// <summary>
/// Initializes a new instance of the <see cref="PostProcessingEffects"/> class.
/// </summary>
public PostProcessingEffects()
{
AmbientOcclusion = new AmbientOcclusion();
LocalReflections = new LocalReflections();
DepthOfField = new DepthOfField();
luminanceEffect = new LuminanceEffect();
BrightFilter = new BrightFilter();
Bloom = new Bloom();
LightStreak = new LightStreak();
LensFlare = new LensFlare();
Antialiasing = new FXAAEffect();
rangeCompress = new ImageEffectShader("RangeCompressorShader");
rangeDecompress = new ImageEffectShader("RangeDecompressorShader");
colorTransformsGroup = new ColorTransformGroup();
}
protected override void DrawCore(RenderDrawContext context)
{
var input = GetInput(0);
var output = GetOutput(0);
if (input is null || output is null)
{
return;
}
var inputDepthTexture = GetInput(1); // Depth
// Update the parameters for this post effect
if (!Enabled)
{
if (input != output)
{
Scaler.SetInput(input);
Scaler.SetOutput(output);
Scaler.Draw(context);
}
return;
}
// If input == output, copy the input to a temporary texture
if (input == output)
{
var newInput = NewScopedRenderTarget2D(input.Width, input.Height, input.Format);
context.CommandList.Copy(input, newInput);
input = newInput;
}
var currentInput = input;
// Draw outline before AA
if (Outline.Enabled && inputDepthTexture != null)
{
// Outline
var outlineOutput = NewScopedRenderTarget2D(input.Width, input.Height, input.Format);
Outline.SetColorDepthInput(currentInput, inputDepthTexture, context.RenderContext.RenderView.NearClipPlane, context.RenderContext.RenderView.FarClipPlane);
Outline.SetOutput(outlineOutput);
Outline.Draw(context);
currentInput = outlineOutput;
}
var fxaa = Antialiasing as FXAAEffect;
bool aaFirst = Bloom != null && Bloom.StableConvolution;
bool needAA = Antialiasing != null && Antialiasing.Enabled;
// Do AA here, first. (hybrid method from Karis2013)
if (aaFirst && needAA)
{
// do AA:
if (fxaa != null)
{
fxaa.InputLuminanceInAlpha = true;
}
var bufferIndex = 1;
if (Antialiasing.RequiresDepthBuffer)
{
Antialiasing.SetInput(bufferIndex++, inputDepthTexture);
}
bool requiresVelocityBuffer = Antialiasing.RequiresVelocityBuffer;
if (requiresVelocityBuffer)
{
Antialiasing.SetInput(bufferIndex++, GetInput(6));
}
var aaSurface = NewScopedRenderTarget2D(input.Width, input.Height, input.Format);
if (Antialiasing.NeedRangeDecompress)
{
// Explanation:
// The Karis method (Unreal Engine 4.1x), uses a hybrid pipeline to execute AA.
// The AA is usually done at the end of the pipeline, but we don't benefit from
// AA for the posteffects, which is a shame.
// The Karis method, executes AA at the beginning, but for AA to be correct, it
// must work post tonemapping, and even more in fact, in gamma space too. Plus,
// it waits for the alpha=luma to be a "perceptive luma" so also gamma space.
// In our case, working in gamma space created monstruous outlining artefacts
// around exageratedly strong constrasted objects (way in HDR range).
// So AA works in linear space, but still with gamma luma, as a light tradeoff
// to supress artefacts.
// Create a 16 bits target for FXAA:
// Render range compression & perceptual luma to alpha channel:
rangeCompress.SetInput(currentInput);
rangeCompress.SetOutput(aaSurface);
rangeCompress.Draw(context);
Antialiasing.SetInput(0, aaSurface);
Antialiasing.SetOutput(currentInput);
Antialiasing.Draw(context);
// Reverse tone LDR to HDR:
rangeDecompress.SetInput(currentInput);
rangeDecompress.SetOutput(aaSurface);
rangeDecompress.Draw(context);
}
else
{
Antialiasing.SetInput(0, currentInput);
Antialiasing.SetOutput(aaSurface);
Antialiasing.Draw(context);
}
currentInput = aaSurface;
}
if (AmbientOcclusion.Enabled && inputDepthTexture != null)
{
// Ambient Occlusion
var aoOutput = NewScopedRenderTarget2D(input.Width, input.Height, input.Format);
AmbientOcclusion.SetColorDepthInput(currentInput, inputDepthTexture);
AmbientOcclusion.SetOutput(aoOutput);
AmbientOcclusion.Draw(context);
currentInput = aoOutput;
}
if (LocalReflections.Enabled && inputDepthTexture != null)
{
var normalsBuffer = GetInput(2);
var specularRoughnessBuffer = GetInput(3);
if (normalsBuffer != null && specularRoughnessBuffer != null)
{
// Local reflections
var rlrOutput = NewScopedRenderTarget2D(input.Width, input.Height, input.Format);
LocalReflections.SetInputSurfaces(currentInput, inputDepthTexture, normalsBuffer, specularRoughnessBuffer);
LocalReflections.SetOutput(rlrOutput);
LocalReflections.Draw(context);
currentInput = rlrOutput;
}
}
if (DepthOfField.Enabled && inputDepthTexture != null)
{
// DoF
var dofOutput = NewScopedRenderTarget2D(input.Width, input.Height, input.Format);
DepthOfField.SetColorDepthInput(currentInput, inputDepthTexture);
DepthOfField.SetOutput(dofOutput);
DepthOfField.Draw(context);
currentInput = dofOutput;
}
if (Fog.Enabled && inputDepthTexture != null)
{
// Fog
var fogOutput = NewScopedRenderTarget2D(input.Width, input.Height, input.Format);
Fog.SetColorDepthInput(currentInput, inputDepthTexture, context.RenderContext.RenderView.NearClipPlane, context.RenderContext.RenderView.FarClipPlane);
Fog.SetOutput(fogOutput);
Fog.Draw(context);
currentInput = fogOutput;
}
// Luminance pass (only if tone mapping is enabled)
// TODO: This is not super pluggable to have this kind of dependencies. Check how to improve this
var toneMap = colorTransformsGroup.Transforms.Get <ToneMap>();
if (colorTransformsGroup.Enabled && toneMap != null && toneMap.Enabled)
{
Texture luminanceTexture = null;
if (toneMap.UseLocalLuminance)
{
const int localLuminanceDownScale = 3;
// The luminance chain uses power-of-two intermediate targets, so it expects to output to one as well
var lumWidth = Math.Min(MathUtil.NextPowerOfTwo(currentInput.Size.Width), MathUtil.NextPowerOfTwo(currentInput.Size.Height));
lumWidth = Math.Max(1, lumWidth / 2);
var lumSize = new Size3(lumWidth, lumWidth, 1).Down2(localLuminanceDownScale);
luminanceTexture = NewScopedRenderTarget2D(lumSize.Width, lumSize.Height, PixelFormat.R16_Float, 1);
luminanceEffect.SetOutput(luminanceTexture);
}
luminanceEffect.EnableLocalLuminanceCalculation = toneMap.UseLocalLuminance;
luminanceEffect.SetInput(currentInput);
luminanceEffect.Draw(context);
// Set this parameter that will be used by the tone mapping
colorTransformsGroup.Parameters.Set(LuminanceEffect.LuminanceResult, new LuminanceResult(luminanceEffect.AverageLuminance, luminanceTexture));
}
if (BrightFilter.Enabled && (Bloom.Enabled || LightStreak.Enabled || LensFlare.Enabled))
{
Texture brightTexture = NewScopedRenderTarget2D(currentInput.Width, currentInput.Height, currentInput.Format, 1);
// Bright filter pass
BrightFilter.SetInput(currentInput);
BrightFilter.SetOutput(brightTexture);
BrightFilter.Draw(context);
// Bloom pass
if (Bloom.Enabled)
{
Bloom.SetInput(brightTexture);
Bloom.SetOutput(currentInput);
Bloom.Draw(context);
}
// Light streak pass
if (LightStreak.Enabled)
{
LightStreak.SetInput(brightTexture);
LightStreak.SetOutput(currentInput);
LightStreak.Draw(context);
}
// Lens flare pass
if (LensFlare.Enabled)
{
LensFlare.SetInput(brightTexture);
LensFlare.SetOutput(currentInput);
LensFlare.Draw(context);
}
}
bool aaLast = needAA && !aaFirst;
var toneOutput = aaLast ? NewScopedRenderTarget2D(input.Width, input.Height, input.Format) : output;
// When FXAA is enabled we need to detect whether the ColorTransformGroup should output the Luminance into the alpha or not
var luminanceToChannelTransform = colorTransformsGroup.PostTransforms.Get <LuminanceToChannelTransform>();
if (fxaa != null)
{
if (luminanceToChannelTransform is null)
{
luminanceToChannelTransform = new LuminanceToChannelTransform {
ColorChannel = ColorChannel.A
};
colorTransformsGroup.PostTransforms.Add(luminanceToChannelTransform);
}
// Only enabled when FXAA is enabled and InputLuminanceInAlpha is true
luminanceToChannelTransform.Enabled = fxaa.Enabled && fxaa.InputLuminanceInAlpha;
}
else if (luminanceToChannelTransform != null)
{
luminanceToChannelTransform.Enabled = false;
}
// Color transform group pass (tonemap, color grading)
var lastEffect = colorTransformsGroup.Enabled ? (ImageEffect)colorTransformsGroup : Scaler;
lastEffect.SetInput(currentInput);
lastEffect.SetOutput(toneOutput);
lastEffect.Draw(context);
// Do AA here, last, if not already done.
if (aaLast)
{
Antialiasing.SetInput(toneOutput);
Antialiasing.SetOutput(output);
Antialiasing.Draw(context);
}
}
