Method Render

Source/Engine/Renderer/AtmospherePreCompute.cpp:329–509

}

void AtmospherePreComputeImpl::Render(RenderTask* task, GPUContext* context)
{
    // If job has been cancelled (eg. on window close)
    if (_wasCancelled)
    {
        LOG(Warning, "AtmospherePreCompute job cancelled");
        return;
    }
    ASSERT(_isUpdatePending && _updateFrameNumber == 0);
    PROFILE_GPU_CPU("AtmospherePreCompute");

    // Allocate temporary render targets
    auto desc = GPUTextureDescription::New2D(IrradianceTexWidth, IrradianceTexHeight, PixelFormat::R16G16B16A16_Float, GPUTextureFlags::ShaderResource | GPUTextureFlags::RenderTarget);
    auto AtmosphereDeltaE = RenderTargetPool::Get(desc);
    desc = GPUTextureDescription::New3D(InscatterWidth, InscatterHeight, InscatterDepth, PixelFormat::R16G16B16A16_Float, GPUTextureFlags::ShaderResource | GPUTextureFlags::RenderTarget | GPUTextureFlags::PerSliceViews);
    auto AtmosphereDeltaSR = RenderTargetPool::Get(desc);
    desc = GPUTextureDescription::New3D(InscatterWidth, InscatterHeight, InscatterDepth, PixelFormat::R16G16B16A16_Float, GPUTextureFlags::ShaderResource | GPUTextureFlags::RenderTarget | GPUTextureFlags::PerSliceViews);
    auto AtmosphereDeltaSM = RenderTargetPool::Get(desc);
    desc = GPUTextureDescription::New3D(InscatterWidth, InscatterHeight, InscatterDepth, PixelFormat::R16G16B16A16_Float, GPUTextureFlags::ShaderResource | GPUTextureFlags::RenderTarget | GPUTextureFlags::PerSliceViews);
    auto AtmosphereDeltaJ = RenderTargetPool::Get(desc);
    if (!AtmosphereDeltaE || !AtmosphereDeltaSR || !AtmosphereDeltaSM || !AtmosphereDeltaJ)
        return;
    RENDER_TARGET_POOL_SET_NAME(AtmosphereDeltaE, "AtmospherePreCompute.DeltaE");
    RENDER_TARGET_POOL_SET_NAME(AtmosphereDeltaSR, "AtmospherePreCompute.DeltaSR");
    RENDER_TARGET_POOL_SET_NAME(AtmosphereDeltaSM, "AtmospherePreCompute.DeltaSM");
    RENDER_TARGET_POOL_SET_NAME(AtmosphereDeltaJ, "AtmospherePreCompute.DeltaJ");

    const auto shader = _shader->GetShader();
    const auto cb = shader->GetCB(0);
    Data data;

    // Compute transmittance texture T (line 1 in algorithm 4.1)
    context->SetRenderTarget(*AtmosphereTransmittance);
    context->SetViewportAndScissors((float)TransmittanceTexWidth, (float)TransmittanceTexHeight);
    context->SetState(_psTransmittance);
    context->DrawFullscreenTriangle();
    context->ResetRenderTarget();

    // Compute irradiance texture deltaE (line 2 in algorithm 4.1)
    context->SetRenderTarget(*AtmosphereDeltaE);
    context->SetViewportAndScissors((float)IrradianceTexWidth, (float)IrradianceTexHeight);
    context->BindSR(0, AtmosphereTransmittance);
    context->SetState(_psIrradiance1);
    context->DrawFullscreenTriangle();
    context->ResetRenderTarget();

    // Compute single scattering texture deltaS (line 3 in algorithm 4.1)
    // Rayleigh and Mie separated in deltaSR + deltaSM
    context->SetViewportAndScissors((float)InscatterWidth, (float)InscatterHeight);
    context->SetState(_psInscatter1_A);
    for (int32 layer = 0; layer < InscatterAltitudeSampleNum; layer++)
    {
        GetLayerValue(layer, data.AtmosphereR, data.dhdh);
        data.AtmosphereLayer = layer;
        context->UpdateCB(cb, &data);
        context->BindCB(0, cb);

        context->SetRenderTarget(AtmosphereDeltaSR->View(layer));