预滤波HDR环境贴图

[TOMBrian881]

您好，目前我发现镜面IBL中的预滤波HDR环境贴图并非是根据粗糙度生成的mipMap图，这导致了对于不同粗糙度的镜面反射都一样

可以从上面的图片看到，铁桶上方锈迹斑斑的地方反射也很强

 // Prefilter
osg::ref_ptr<osg::Image> img1 = new osg::Image;
{
    osg::Shader* fs = osgDB::readShaderFile(
        osg::Shader::FRAGMENT, SHADER_DIR "std_environment_prefiltering.frag.glsl");
    osgVerse::Pipeline::createShaderDefinitions(fs, 100, 130);
    img1->allocateImage(w, h, 1, GL_RGB, GL_UNSIGNED_BYTE);
    img1->setInternalTextureFormat(GL_RGB8);

    osg::ref_ptr<osg::Program> prog = new osg::Program;
    prog->addShader(vs); prog->addShader(fs);
    cam1 = createRTTCameraForImage(osg::Camera::COLOR_BUFFER, img1.get(), true);
    cam1->getOrCreateStateSet()->setAttributeAndModes(
        prog.get(), osg::StateAttribute::ON | osg::StateAttribute::OVERRIDE);
    cam1->getOrCreateStateSet()->setTextureAttributeAndModes(0, hdrMap.get());
    cam1->getOrCreateStateSet()->addUniform(new osg::Uniform("EnvironmentMap", (int)0));
    cam1->getOrCreateStateSet()->addUniform(new osg::Uniform("GlobalRoughness", 4.0f));
}

[TOMBrian881]

同样的模型在filament的渲染结果

[xarray]

您好，非常感谢。我会检查一下生成数据的程序，有可能是没有正确使用texLod函数。如果您能帮忙找到问题所在并提交pull request，那就再感谢不过了~