Method initIntegrator

Source/Falcor/Scene/Lights/LightCollection.cpp:117–170

    }

    void LightCollection::initIntegrator(RenderContext* pRenderContext, const Scene& scene)
    {
        // The current algorithm rasterizes emissive triangles in texture space,
        // and uses atomic operations to sum up the contribution from all covered texels.
        // We do this in a raster pass, so we get one thread per texel/triangle.

        // Check for required features.
        if (!mpDevice->isFeatureSupported(Device::SupportedFeatures::ConservativeRasterizationTier3))
        {
            FALCOR_THROW("LightCollection requires conservative rasterization tier 3 support.");
        }
        if (!mpDevice->isShaderModelSupported(ShaderModel::SM6_6))
        {
            FALCOR_THROW("LightCollection requires Shader Model 6.6 support.");
        }

        // Create program.
        auto defines = scene.getSceneDefines();
        defines.add("INTEGRATOR_PASS", "1");

        ProgramDesc desc;
        desc.addShaderLibrary(kEmissiveIntegratorFile).vsEntry("vsMain").gsEntry("gsMain").psEntry("psMain");
        mIntegrator.pProgram = Program::create(mpDevice, desc, defines);

        // Create graphics state.
        mIntegrator.pState = GraphicsState::create(mpDevice);

        // Set state.
        mIntegrator.pState->setProgram(mIntegrator.pProgram);
        mIntegrator.pState->setVao(Vao::create(Vao::Topology::PointList));

        // Set viewport. Note we don't bind any render targets so the size just determines the dispatch limits.
        const uint32_t vpDim = 16384;       // 16K x 16K
        mIntegrator.pState->setViewport(0, GraphicsState::Viewport(0.f, 0.f, (float)vpDim, (float)vpDim, 0.f, 1.f));
        mIntegrator.pProgram->addDefine("_VIEWPORT_DIM", std::to_string(vpDim));    // Pass size to shader

        // Set raster state to disable culling. We don't care about winding in texture space when integrating.
        RasterizerState::Desc rsDesc;
        rsDesc.setCullMode(RasterizerState::CullMode::None);
        rsDesc.setFillMode(RasterizerState::FillMode::Solid);
        rsDesc.setConservativeRasterization(true);
        mIntegrator.pState->setRasterizerState(RasterizerState::create(rsDesc));

        // Set depth-stencil state to disable depth test/writes.
        DepthStencilState::Desc dsDesc;
        dsDesc.setDepthEnabled(false);
        dsDesc.setDepthWriteMask(false);
        mIntegrator.pState->setDepthStencilState(DepthStencilState::create(dsDesc));

        // Create sampler for texel fetch. This is identical to material sampler but uses point sampling.
        Sampler::Desc samplerDesc = mpSamplerState ? mpSamplerState->getDesc() : Sampler::Desc();
        samplerDesc.setFilterMode(TextureFilteringMode::Point, TextureFilteringMode::Point, TextureFilteringMode::Point);
        mIntegrator.pPointSampler = mpDevice->createSampler(samplerDesc);
    }

    void LightCollection::setupMeshLights(const Scene& scene)
    {