Method updateRaytracingAABBData

Source/Falcor/Scene/Scene.cpp:944–1046

    }

    IScene::UpdateFlags Scene::updateRaytracingAABBData(bool forceUpdate)
    {
        // This function updates the global list of AABBs for all procedural primitives.
        // TODO: Move this code to the GPU. Then the CPU copies of some buffers won't be needed anymore.
        IScene::UpdateFlags flags = IScene::UpdateFlags::None;

        size_t curveAABBCount = 0;
        for (const auto& curve : mCurveDesc) curveAABBCount += curve.indexCount;

        size_t customAABBCount = mCustomPrimitiveAABBs.size();
        size_t totalAABBCount = curveAABBCount + customAABBCount;

        if (totalAABBCount > std::numeric_limits<uint32_t>::max())
        {
            FALCOR_THROW("Procedural primitive count exceeds the maximum");
        }

        // If there are no procedural primitives, clear the CPU buffer and return.
        // We'll leave the GPU buffer to be lazily re-allocated when needed.
        if (totalAABBCount == 0)
        {
            mRtAABBRaw.clear();
            return flags;
        }

        mRtAABBRaw.resize(totalAABBCount);
        uint32_t index = 0;

        size_t firstUpdated = std::numeric_limits<size_t>::max();
        size_t lastUpdated = 0;

        if (forceUpdate)
        {
            // Compute AABBs of curve segments.
            for (const auto& curve : mCurveDesc)
            {
                // Track range of updated AABBs.
                // TODO: Per-curve flag to indicate changes. For now assume all curves need updating.
                firstUpdated = std::min(firstUpdated, (size_t)index);
                lastUpdated = std::max(lastUpdated, (size_t)index + curve.indexCount);

                const auto* indexData = &mCurveIndexData[curve.ibOffset];
                const auto* staticData = &mCurveStaticData[curve.vbOffset];

                for (uint32_t j = 0; j < curve.indexCount; j++)
                {
                    AABB curveSegBB;
                    uint32_t v = indexData[j];

                    for (uint32_t k = 0; k <= curve.degree; k++)
                    {
                        curveSegBB.include(staticData[v + k].position - float3(staticData[v + k].radius));
                        curveSegBB.include(staticData[v + k].position + float3(staticData[v + k].radius));
                    }

                    mRtAABBRaw[index++] = static_cast<RtAABB>(curveSegBB);
                }
                flags |= IScene::UpdateFlags::CurvesMoved;