Method computeAlbedoLUT

Source/Falcor/Scene/Material/MERLFile.cpp:186–214

    }

    void MERLFile::computeAlbedoLUT(ref<Device> pDevice, const size_t binCount)
    {
        logInfo("MERLFile: Computing albedo LUT for MERL BRDF '{}'...", mDesc.name);

        std::vector<float> cosThetas(binCount);
        for (uint32_t i = 0; i < binCount; i++) cosThetas[i] = (float)(i + 1) / binCount;

        // Create MERL material based on loaded data.
        ref<MERLMaterial> pMaterial = make_ref<MERLMaterial>(pDevice, *this);

        // Create and update dummy scene containing the material.
        Scene::SceneData sceneData;
        sceneData.pMaterials = std::make_unique<MaterialSystem>(pDevice);
        MaterialID materialID = sceneData.pMaterials->addMaterial(pMaterial);

        ref<Scene> pScene = Scene::create(pDevice, std::move(sceneData));
        pScene->update(pDevice->getRenderContext(), 0.0);

        // Create BSDF integrator utility.
        BSDFIntegrator integrator(pDevice, pScene);

        // Integrate BSDF.
        auto albedos = integrator.integrateIsotropic(pDevice->getRenderContext(), materialID, cosThetas);

        // Copy result into RGBA format needed for texture creation.
        mAlbedoLUT.resize(binCount);
        for (uint32_t i = 0; i < binCount; i++)
            mAlbedoLUT[i] = float4(albedos[i], 1.f);
    }
}