 Hi! Welcome to this tutorial! We'll introduce how to set lighting for an interior space with D5 Render 2.4. In this episode, you'll learn the logic behind the lighting system of D5, which includes the optimized D5 global illumination. As D5 Render keeps making great strides, interior designers will output high-quality works more efficiently with its help. The GI solution decides whether the lighting can perform well enough to reach photorealism. For interior designers, a great GI solution is critical because there are many dark corners and shadows deep inside an interior space. Many real-time renderers can't approach these issues within a very short time, so designers have to spend a lot of time post-processing the renderings. Well, how does D5 GI perform? In this scene, we only used HDRI with an intensity of around 0.2 without any artificial lights. You can see that D5 performs better behind the walls. It retains more high-frequency details of the shadows and has more realistic lighting transitions. It proves that the D5 GI strikes a good balance between speed and quality. Skylight alone can offer sufficient lighting, which saves you much time adding artificial lights. Let's see how to set realistic lighting powered by this solution. First, we'll introduce how to set natural lighting in the environment panel, which includes HDRI and Geo and Sky. Geo and Sky in D5 simulates the natural lighting in the real world. You can precisely control the position, light intensity, and disk radius of the sun. HDRI comes in handy for atmospheric natural lighting. You can use the preset ones in D5 or import your own. Don't forget to set a proper intensity for the sky and the sun. Please note that some have a preset sun. You can use it or customize one as you need. For the preset sun, you can't change its height, but can rotate the HDRI to a proper angle, thus getting a proper lighting effect, which is very convenient. For the custom sun, you can set its altitude and azimuth. Here's a tip that helps you better display the natural lighting. Volume light. Go to environment, weather. Here you can create rain snow fog cloud wind with one click. Switch on the fog option. Check volume light and adjust its scattering intensity. Now you can clearly see the light beams. As we've said before, HDRI already offers a great lighting effect for interior spaces, so we just need a few artificial lights to add more reflection details. D5 has four kinds of artificial lights. A point light emits light in the same way as the sun, while a rectangular light looks like a square board. You can light up a large space with a rectangular light and a particular area with a point light. A strip light is a special kind of rectangular light which looks very narrow. You can put it in a cabinet for decorative lighting. A spotlight is usually used to highlight a specific object or area, thus creating a special vibe. In this scene, for example, a spotlight is put above the sofa, leading the audiences to imagine a person reading magazines. There are three widely used parameters of artificial lights. Intensity, attenuation radius, and temperature. Intensity controls how bright the light is, attenuation radius for how far the light can illuminate and temperature for the color of light. You can create focused beams for a rectangular light or spotlight with barn door angle or cone angle. To learn more about the artificial lights, please read the user manual of D5 Render. We'll also demonstrate how to set these parameters in the following cases. That completes our tutorial. We'll show how to set interior day lighting in the next episode. Thanks for watching!