Join Brian Bradley for an in-depth discussion in this video Creating natural daylight with V-Ray Sun and Sky, part of SketchUp Rendering: Using V-Ray 2.
- There are three main lighting elements in the V-Ray engine that are set up and ready for us to work with each and every time we create a new scene in the sketch or publication. These are indirect, or bounced light, provided courtesy of V-Ray's global illumination engines, and natural looking daylight simulation provided by the built-in V-Ray sun and sky environment, and a view of the scene that makes use of the V-Ray physical camera at render time, which gives us the ability to render our scenes in a genuinely photographic manner. However, if I go ahead and take a render of our start scene here...
you can see that we actually have right now is a completely black environment. This is because I have deliberately set up the scene file here so as to force us to have to manually build the lighting system that we want to use. Hopefully helping us familiarize ourselves with the components that make up V-Ray's daylighting system in the process. Do keep in mind though, that both GI and the V-Ray physical camera are still enabled, and at work in this scene. To start building our daylight environment then, the first thing we need to do is open up the V-Ray options dialogue and jump into the environment roll-out.
Here we have four options that essentially give us complete control of the rendering of our general environment in the scene. The two options we are interested in at this moment in time being the GI, or global illumination skylight, and the reflection refraction background controls. Let's take a look first of all at the background controls by putting a check in the box in order to enable them. As the name suggests these options give us the ability to use either solid color, or indeed an image file, as the background or backdrop for our rendered images.
Meaning that anywhere we see past geometry in our scene to the virtual environment, so quite literally anywhere in the sketch or viewport that we currently see either the ground color or the sky gradients these will be areas where our background color or image map will show up in the renders that we take. The V-Ray sky map is a procedural, high dynamic range image map, that has been designed by Chaos Group to mimic the real-world behavior of a clear sky environment, making it the perfect backdrop for arch-viz renders.
To make use of it here let's click on the map button, and then in the V-Ray texture editor that opens up, come over to the dropdown on the left-hand side of the UI and select the TexSky option. Once selected, we can alter our sky's appearance in renders by using the map controls that now become available. So, brightness, turbidity, ozone, and water vapor, to name just four. We can also, using SketchUp's zone shadow setting controls, have the month of year and current time of day automatically affect the appearance of our sky as well.
To use that feature though, we would need to make certain that the sunlight option gets enabled once we actually add the TexSky map as a lighting element to our scene. Let's click okay to close the texture editor then, make certain that we put a check in the use map checkbox, and then try out a render in order to see what we have. Which as backdrops go, looks fairly good. Of course, all we have at this moment in time is a background in our render, we are still getting no daylight simulation from this set-up. To enable that, we need to put a check in the GI skylight checkbox.
This tells V-Ray to essentially provide us with 360 degrees of indirect skylight illumination in the scene. As this is not a direct light solution though, we do need to have V-Ray's GI systems turned on in order for it to work, which is noted in the introduction we already do have in this scene. With no map applied, as is the default in V-Ray for SketchUp, V-Ray will use the color swatch and value spinners that we see here in order to determine the color and brightness of the light that we will get from this GI skylight.
To get a more natural daylight look though, we want to go ahead and again run through the process of adding a high dynamic range TexSky map to the map slot. Making certain, of course, to enable the use map checkbox once we exit out of the texture editor. When used in this slot, the TexSky map will add real-world levels of light energy to our scene. Which is why, if I go ahead and take a render... We now get a very obvious skylight effect, helped, of course, by our current camera exposure, and GI engine settings.
You will, of course, have noticed that we don't actually have any kind of direct sunlight in the image at this moment in time. This is because we have yet to go ahead and enable the sunlight option in the TexSky map. To fix that oversight, let's jump back into the texture editor, select the Sun 1 option from the dropdown, and then enable that. Once we do our default sky options become grayed out as the appearance of the sky, and of course the sun itself, will now be controlled by the sun options that have sprung to life.
So we still have water vapor, turbidity, and ozone controls for the sky, but we now also have settings such as size and shadow options for the sun itself. With that done, let's click okay and take one last render for this exercise. What we have in place now is a fully automated daylight simulation system that is giving us a very nice sunny afternoon look to our renders. And remember, with V-Ray and SketchUp, we do of course get all of this set-up, by default whenever we start a new scene.
Hopefully though, seeing how this daylight system is actually constructed can help us take full control and full advantage of this very powerful V-Ray lighting feature.
- Locating V-Ray tools and features
- Using the RT Engine
- Creating daylight with V-Ray Sun and Sky
- Using image-based lighting
- Working with irradiance mapping
- Handling perspective correction in the physical camera
- Setting up a depth of field effect
- Creating and applying V-Ray materials
- Using fixed-rate sampling
- Color mapping
- Working with V-Ray proxies