Lighting an Outdoor Scene in Blender

Blender 2.5 Lighting and Rendering

Bring your 3D world to life with lighting, compositing, and rendering

• Render spectacular scenes with realistic lighting in any 3D application using interior and exterior lighting techniques
• Give an amazing look to 3D scenes by applying light rigs and shadow effects
• Apply color effects to your scene by changing the World and Lamp color values
• A step-by-step guide with practical examples that help add dimensionality to your scene       

Getting the right files

Before we get started, we need a scene to work with. There are three scenes provided for our use—an outdoor scene, an indoor scene, and a hybrid scene that incorporates elements that are found both inside as well as outside. All these files can be downloaded from http://www.cgshark.com/lightingand-rendering/

The file we are going to use for this scene is called exterior.blend. This scene contains a tricycle, which we will light as if it were a product being promoted for a company.

To download the files for this tutorial, visit http://www.cgshark.com/lighting-and-rendering/ and select exterior.blend.

Blender render settings

In computer graphics, a two-dimensional image is created from three-dimensional data through a computational process known as rendering. It's important to understand how to customize Blender's internal renderer settings to produce a final result that's optimized for our project, be it a single image or a full-length film. With the settings Blender provides us, we can set frame rates for animation, image quality, image resolution, and many other essential parts needed to produce that optimized final result.

The Scene menu

We can access these render settings through the Scene menu. Here, we can adjust a myriad of settings. For the sake of these projects, we are only going to be concerned with:

• Which window Blender will render our image in
• How render layers are set up
• Image dimensions
• Output location and file type

Render settings

The first settings we see when we look at the Scene menu are the Render settings. Here, we can tell Blender to render the current frame or an animation using the render buttons.

We can also choose what type of window we want Blender to render our image in using the Display options.

The first option (and the one chosen by default) is Full Screen. This renders our image in a window that overlaps the three-dimensional window in our scene. To restore the three-dimensional view, select the Back to Previous button at the top of the window.



The next option is the Image Editor that Blender uses both for rendering as well as UV editing. This is especially useful when using the Compositor, allowing us to see our result alongside our composite node setup. By default, Blender replaces the three-dimensional window with the Image Editor.



The last option is the option that Blender has used, by default, since day one—New Window. This means that Blender will render the image in a newly created window, separate from the rest of the program's interface.



For the sake of these projects, we're going to keep this setting at the default setting—Full Screen.

Dimensions settings

These are some of the most important settings that we can set when dealing with optimizing our project output. We can set the image size, frame rate, frame range, and aspect ratio of our render. Luckily for us, Blender provides us with preset render settings, common in the film industry:

• HDTV 1080P
• HDTV 720P
• TV NTSC
• TV PAL
• TV PAL 16:9

Because we want to keep our render times relatively low for our projects, we're going to set our preset dimensions to TV NTSC, which results in an image 720 pixels wide by 480 pixels high. If you're interested in learning more about how the other formats behave, feel free to visit http://en.wikipedia.org/wiki/Display_resolution.

Output settings

These settings are an important factor when determining how we want our final product to be viewed. Blender provides us with numerous image and video types to choose from.

When rendering an animation or image sequence, it's always easier to manually set the folder we want Blender to save to. We can tell Blender where we want it to save by establishing the path in the output settings. By default on Macintosh, Blender saves to the /tmp/ folder.

Now that we understand how Blender's renderer works, we can start working with our scene!

Establishing a workflow

The key to constantly producing high-quality work is to establish a well-tested and efficient workflow. Everybody's workflow is different, but we are going to follow this series of steps:

1. Evaluate what the scene we are lighting will require.
2. Plan how we want to lay out the lamps in our scene.
3. Set lamp positions, intensities, colors, and shadows, if applicable.
4. Add materials and textures.
5. Tweak until we're satisfied.

Evaluating our scene

Before we even begin to approach a computer, we need to think about our scene from a conceptual perspective. This is important, because knowing everything about our scene and the story that's taking place will help us produce a more realistic result.

To help kick start this process, we can ask ourselves a series of questions that will get us thinking about what's happening in our scene. These questions can pertain to an entire array of possibilities and conditions, including:

• Weather
  • What is the weather like on this particular day? What was it like the day before or the day after?
  • Is it cloudy, sunny, or overcast? Did it rain or snow?

• Source of light
  • Where is the light coming from? Is it in front of, to the side, or even behind the object?
  • Remember, light is reflected and refracted until all energy is absorbed; this not only affects the color of the light, but the quality as well. Do we need to add additional light sources to simulate this effect?

• Scale of light sources
  • What is the scale of our light sources in relation to our three-dimensional scene? Believe it or not, this factor carries a lot of weight when it comes to the quality of the final render. If any lights feel out of place, it could potentially affect the believability of the final product.

The goal of these questions is to prove to ourselves that the scene we're lighting has the potential to exist in real life. It's much harder, if not impossible, to light a scene if we don't know how it could possibly act in the real world.

Let's take a look at these questions.

• What is the weather like? In our case, we're not concerned with anything too challenging, weather wise. The goal of this tutorial is to depict our tricycle in an environment that reflects the effects of a sunny, cloudless day. To achieve this, we are going to use lights with blue and yellow hues for simulating the effect the sun and sky will have on our tricycle.
• What are the sources of our light and where are they coming from in relation to our scene? In a real situation, the sun would provide most of the light, so we'll need a key light that simulates how the sun works. In our case, we can use a Sun lamp. The key to positioning light sources within a three-dimensional scene is to find a compromise between achieving the desired mood of the image and effectively illuminating the object being presented.
• What is the scale of our light sources? The sun is rather large, but because of the nature of the Sun lamp in Blender, we don't have to worry about the scale of the lamp in our three-dimensional scene. Sometimes—more commonly when working with indoor scenes, such as the scene we'll approach later—certain light sources need to be of certain sizes in relation to our scene, otherwise the final result will feel unnatural.

Although we will be using a realistic approach to materials, textures, and lighting, we are going to present this scene as a product visualization. This means that we won't explicitly show a ground plane, allowing the viewer to focus on the product being presented, in this case, our tricycle.