Method RenderShadowMap

MSAAFilter/MeshRenderer.cpp:552–757

Renders meshes using cascaded shadow mapping

// Renders meshes using cascaded shadow mapping
void MeshRenderer::RenderShadowMap(ID3D11DeviceContext* context, const Camera& camera,
                                   const Float4x4& world)
{
    PIXEvent event(L"Mesh Shadow Map Rendering");

    // Get the current render targets + viewport
    ID3D11RenderTargetView* renderTargets[D3D11_SIMULTANEOUS_RENDER_TARGET_COUNT] = { NULL };
    ID3D11DepthStencilView* depthStencil = NULL;
    context->OMGetRenderTargets(D3D11_SIMULTANEOUS_RENDER_TARGET_COUNT, renderTargets, &depthStencil);

    uint32 numViewports = D3D11_VIEWPORT_AND_SCISSORRECT_OBJECT_COUNT_PER_PIPELINE;
    D3D11_VIEWPORT oldViewports[D3D11_VIEWPORT_AND_SCISSORRECT_OBJECT_COUNT_PER_PIPELINE];
    context->RSGetViewports(&numViewports, oldViewports);

    const float sMapSize = static_cast<float>(ShadowMapSize);

    const float MinDistance = shadowDepthBounds.x;
    const float MaxDistance = shadowDepthBounds.y;

    // Compute the split distances based on the partitioning mode
    float CascadeSplits[4] = { 0.0f, 0.0f, 0.0f, 0.0f };

    {
        float lambda = 1.0f;

        float nearClip = camera.NearClip();
        float farClip = camera.FarClip();
        float clipRange = farClip - nearClip;

        float minZ = nearClip + MinDistance * clipRange;
        float maxZ = nearClip + MaxDistance * clipRange;

        float range = maxZ - minZ;
        float ratio = maxZ / minZ;

        for(uint32 i = 0; i < NumCascades; ++i)
        {
            float p = (i + 1) / static_cast<float>(NumCascades);
            float log = minZ * std::pow(ratio, p);
            float uniform = minZ + range * p;
            float d = lambda * (log - uniform) + uniform;
            CascadeSplits[i] = (d - nearClip) / clipRange;
        }
    }

    Float3 c0Extents;
    Float4x4 c0Matrix;

    // Render the meshes to each cascade
    for(uint32 cascadeIdx = 0; cascadeIdx < NumCascades; ++cascadeIdx)
    {
        PIXEvent cascadeEvent((L"Rendering Shadow Map Cascade " + ToString(cascadeIdx)).c_str());

        // Set the viewport
        D3D11_VIEWPORT viewport;
        viewport.TopLeftX = 0.0f;
        viewport.TopLeftY = 0.0f;
        viewport.Width = sMapSize;