Method Prepare

Hydrogent/src/Tasks/HnRenderShadowsTask.cpp:223–282

}

void HnRenderShadowsTask::Prepare(pxr::HdTaskContext* TaskCtx,
                                  pxr::HdRenderIndex* RenderIndex)
{
    m_RenderIndex = RenderIndex;

    m_LightsByShadowSlice.clear();

    const HnRenderDelegate* RenderDelegate = static_cast<const HnRenderDelegate*>(m_RenderIndex->GetRenderDelegate());
    const HnRenderParam*    pRenderParam   = static_cast<const HnRenderParam*>(RenderDelegate->GetRenderParam());
    if (pRenderParam == nullptr)
    {
        UNEXPECTED("Render param is null");
        return;
    }

    if (!pRenderParam->GetUseShadows())
        return;

    PrepareClearDepthPSO(*RenderDelegate);
    PrepareClearDepthVB(*RenderDelegate);

    const Uint32 GeometryVersion =
        (pRenderParam->GetAttribVersion(HnRenderParam::GlobalAttrib::GeometrySubsetDrawItems) +
         pRenderParam->GetAttribVersion(HnRenderParam::GlobalAttrib::MeshGeometry) +
         pRenderParam->GetAttribVersion(HnRenderParam::GlobalAttrib::MeshTransform) +
         pRenderParam->GetAttribVersion(HnRenderParam::GlobalAttrib::MeshVisibility) +
         pRenderParam->GetAttribVersion(HnRenderParam::GlobalAttrib::MeshMaterial));
    static_assert(static_cast<int>(HnRenderParam::GlobalAttrib::Count) == 9, "Please update the code above to handle the new attribute, if necessary.");

    bool GeometryChanged  = m_LastGeometryVersion != GeometryVersion;
    m_LastGeometryVersion = GeometryVersion;

    const auto& Lights = RenderDelegate->GetLights();

    // Sort all shadow lights with dirty shadow maps by shadow map slice
    for (HnLight* Light : Lights)
    {
        if (!Light->ShadowsEnabled())
            continue;

        if (GeometryChanged)
        {
            // Make shadow map dirty even if the light is disabled so that
            // when it is enabled, the shadow map will be updated.
            Light->SetShadowMapDirty(true);
        }

        if (!Light->IsShadowMapDirty())
            continue;

        Int32 ShadowCatingLightId = Light->GetFrameAttribsIndex();
        if (ShadowCatingLightId < 0)
            continue;

        VERIFY(Light->IsVisible(), "Invisible lights should not be assigned shadow casting light index");

        ITextureAtlasSuballocation* pAtlasRegion = Light->GetShadowMapSuballocation();
        m_LightsByShadowSlice.emplace(pAtlasRegion->GetSlice(), Light);