One of the features of V-Ray in Google SketchUp is the ability to produce a representation of the subtle variations of natural sunlight on architectural structures. This allows you and your clients to view shading, reflections, and overall appearance in different light throughout the day. Learn how to efficiently create natural daylight with the V-Ray Sun and Sky in this online video.
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There are three critical V-Ray lighting elements that are already set up and working for us each and every time we start a new scene in SketchUp with the V-Ray plug-in installed. These are indirect illumination, provided by the V-Ray's Global Illumination engines; natural- looking daytime lighting, provided by the VRay Sun and Sky environment; and the V-Ray Physical Camera through which we render our scene in a photographic manner, including the use of exposure controls. However, if at this moment in time we were to take a render in our chapter 02 Daylight_start scene, we would actually see that we have a completely dark environment. This is because we have deliberately set this scene file up so that we have to manually build our day lighting system.
Hopefully, this will help us familiarize ourselves with the components making up these important set of V-Ray lighting controls. Do keep in mind though that the other two elements mentioned, namely, Global Illumination and the V-Ray Physical Camera, are both still enabled, and will be at work in the test renders we make. So to build our daylight environment, we need to first of all open up the V-Ray options dialog for ourselves, so if we come up to the V-Ray toolbar, we can click on the Options dialog icon.
Once that is opened up, we need to find the environment rollout and then we simply open it up by left-mouse-clicking. Here, as you can see, we have four options that really control how V-Ray will render the general environment in our scene. The two options that we're interest in are the GI, or Global Illumination color, which will ultimately control the lighting in our scene; and the BG, or Background Color, controls. As these are the ones that we want to look at first of all, let's put a check in the BG Color box to enable those options for ourselves.
Now, as you may expect, we can set a Background color by means of our color swatch, or we can indeed use a map or an image file that will render in the background by means of our Map button. Now, anywhere that we see past geometry in our scene to the virtual environment or background-- so in visual terms, anywhere that we see the sky gradient in our SketchUp viewport--well, this is where our background color or our map will show up. The VRaySky is a procedural high-dynamic-range image that has really been designed to mimic the real-world behavior of a clear sky environment.
This makes it an excellent backdrop for any kind of visualization render. To use that, we simply left mouse-click on the Map button. In the Texture editor that pops up, we can use the dropdown, and if we just scroll down, you'll find our TexSky entered. With that chosen, you can see we get access to a number of controls that really allow us to change the appearance of our sky. We can use options such as Turbidity, Ozone, Water Vapor, et cetera, all of which will slightly change the look and coloration of our procedural sky.
We can even have SketchUp's Shadow Setting controls--that is, the month of the year, the time of the day--automatically update the appearance of our sky as we make changes to those controls. For that to happen, we would need to make certain that this SunLight option is enabled, so let's click on the button, and in the Select Plugin dialog, let's chose the dropdown, chose SunLight, and click OK. Now you can see our general sky controls become grayed out and if we just scroll down a little bit, you see that we now have access to all of these SunLight controls.
Well of course we're not controlling the SunLight as such in terms of lighting, but we are controlling how the SunLight will affect the look of our procedural sky. So all of the options for changing the sky such as Turbidity and Ozone and Water Vapor are still in here, but we have extra parameters that will update the look of our sky as well. One thing we do need to be aware of is that any changes we make to these controls will eventually be carried over into our scene lighting once we apply the VRaySky map into our GI color slot.
The system has to share a single instance of the TexSky map for both the GI and Background Color options, even though we do actually add the map to each slot independently. We won't see what a difference that has made in terms of what we get in our render, so let's dismiss our dialog, and let's go up to the Start Render icon on the V-Ray toolbar and take a render for ourselves. Now, as you can see, we get a very nice procedural sky gradient as the backdrop for our render. Of course, at this moment in time we still have no lighting in our scene.
To enable that, let's go back into our Options dialog, and this time we want to work with our GI Color control, so again, let's put a check in the box to enable those for ourselves. With that checkbox enabled, V-Ray will now give to us 360 degrees of indirect skylight illumination. Now because this is not a direct light source, we do need to have V-Ray's GI systems turned on in order for this set of controls to give us any lighting in the scene. Notice they are on by default, and as they're enabled in these particular scenes, we don't have any problem there.
Now with no map in the map slot, V-Ray will use this color swatch and the value set in this multiply spinner to really control the coloration and the brightness of the light that comes from our sky. As we want a natural-looking daylight render, we're going to want to add the VRaySky map into our map slot, so let's left-mouse-click on the map button. In the Texture Editor, again, we want to go and find our TexSky map, so let's just scroll down, select that option, and again, we get our controls. And let's just click OK, dismiss those dialogs, and let's see what we have in terms of scene lighting for ourselves.
Because the VRaySky map is, as we mentioned, a high-dynamic-range image and has been designed to add real-world levels of light energy into our environments, what we get is a very nice bright skylight render, helped a little bit of course by our current camera exposure settings. We still don't have any direct light from our sun in the scene though, so let's go back into the Options dialog and add that in for ourselves. So again, click on the Map button and we need to enable our SunLight plug-in. So let's click on the button, use the drop down to select SunLight, and click OK.
Now as well as controlling our sky, we can actually control the appearance of our sun by means of these parameters. Of course, we do need to make certain that our SunLight is enabled. Now we can set the size of the sun as it'll appear in our procedural sky. If we want to, we can make our sun invisible, in terms of scene reflections, and of course, we have a lot of control over how the shadows are looking. So again, let's click OK, dismiss the dialogs, and let's see how that has changed the look or the feel of the lighting in our environment.
And what we see is that with all of those options enabled and working together, that we really get a complete natural-looking daylight look to the scene. Of course, we can change the coloration, the look of our lighting, the look of our procedural sky, simply by updating SketchUp's shadow controls. So we do get all of this by default in V-Ray for SketchUp whenever we start a new scene. Just keep that in mind. All this has only been constructed simply as a means of really helping us become familiar with how the system is working, and hopefully will help us take full control and full advantage of this very powerful V-Ray Lighting feature.
- Installing V-Ray
- Creating natural daylight with V-Ray Sun and Sky
- Bouncing light around with irradiance mapping and light caches
- Setting up a depth-of-field effect
- Creating diffuse and reflective surfaces
- Working with the Adaptive DMC engine
- Manipulating color mapping
- Adding caustic lighting and occlusion effects