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Figure 41-14: The Print Size Wizard lets you set the image dimensions based on paper size and DPI settings.

Using this Print Size Wizard, you can select a Paper Size and Orientation, and a DPI setting and the Image dimensions are computed automatically. You can then click the Render Scene Dialog button to open the Render Scene dialog box with these dimensions. You also can select a file name using the Files button and click the Quick Render button to render an image using the specified dimensions. The only available image format is TIFF.

Creating an Environment

Whether it’s a beautiful landscape or just clouds drifting by, the environment behind the scene can do much to make the scene more believable. In this section, you learn to define an environment using the Rendering Environment (8) menu command.

Environment maps are used as background for the scene and can also be used as images reflected off shiny objects. Environment maps are displayed only in the final rendering and not in the viewports, but you can add a background to any viewport and even set the environment map to be displayed as the viewport backdrop.

Cross-	Chapter 2, “Seeing It All — Working with the Viewports,” covers adding a background image
Reference	to a viewport.

But there is more to an environment than just a background. It also involves altering the global lighting, controlling exposure, and introducing atmosphere effects.

Defining the rendered environment

You create environments in the Environment and Effects dialog box, shown in Figure 41-15, which you can open by choosing Rendering Environment (or by pressing the 8 key). Several settings make up an environment, including a background color or image, global lighting, exposure control, and atmospheric effects.

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Figure 41-15: The Environment and Effects dialog box lets you select a background color or image, define global lighting, control exposure, and work with atmospheric effects.

Setting a background color

The first color swatch in the Environment panel lets you specify a background color. This color appears by default if no environment map is specified or if the Use Map option is disabled (and is black by default). The background color is animatable, so you can set the background color to start black and slowly fade to white.

Using a background image

To select a background image to be used as an environment map, click the Environment Map button in the Environment panel to open the Material/Map browser. If you want to load a bitmap image as the background image, double-click the Bitmap selection to open the Select Bitmap Image dialog box. Locate the bitmap to use, and click OK. The bitmap name appears on the Environment Map button.

Tip If the environment map that you want to use is already displayed in one of the Material Editor sample slots, you can drag it directly from the Material Editor and drop it on the Map button in the Environment panel.

To change any of the environment map parameters (such as the mapping coordinates), you need to load the environment map into the Material Editor. You can do so by dragging the map button from the Environment panel onto one of the sample slots in the Material Editor. After releasing the material, the Instance (Copy) Map dialog box asks whether you want to create an Instance or a Copy. If you select Instance, any parameter changes that you make to the material automatically update the map in the Environment panel.

Cross-	For more information about the types of mapping parameters that are available, see Chapter
Reference	22, “Adding Material Details with Maps.”

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The background image doesn’t need to be an image: You can also load animations. Supported formats include AVI, FLC, and IFL files.

Figure 41-16 shows a scene with an image of the Golden Gate Bridge loaded as the environment map. Viewpoint Datalabs created the airplane model.

Figure 41-16: The results of a background image loaded into the

Environment panel

Setting global lighting

The Tint color swatch in the Global Lighting section of the Environment panel specifies a color used to tint all lights. The Level value increases or decreases the overall lighting level for all lights in the scene. The Ambient color swatch sets the color for the ambient light in the scene, which is the darkest color that any shadows in the scene can be. You can animate all these settings.

Setting exposure

The Exposure Control rollout of the Environment panel lets you control output levels and color rendering ranges. Controlling the exposure of film is a common procedure when working with film and can result in a different look for your scene. Enabling the Exposure Controls can add dynamic range to your rendered images that is more comparable to what the eyes actually see. If you’ve worked with a Histogram in Photoshop, then you’ll understand the impact that the Exposure Controls can have. The default selection is Automatic Exposure Control.

The Active option lets you turn this feature on and off. The Process Background and Environment Maps option causes the exposure settings to affect the background and environment images. When this option is disabled, then only the scene objects are affected by the exposure control settings. The Exposure Control rollout also includes a Render Preview

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button that displays the rendered scene in a tiny pane. The preview pane is small, but for most types of exposure control settings, it is enough. When you click the Render Preview button, the scene is rendered. This preview is then automatically updated whenever a setting is changed.

Automatic, Linear, and Logarithmic Exposure Control

Selecting Automatic Exposure Control from the drop-down list automatically adjusts your rendered output to be closer to what your eyes can detect. Monitors are notoriously bad at reducing the dynamic range of the colors in your rendered image. This setting provides the needed adjustments to match the expanded dynamic range of your eyes.

When the Automatic Exposure Control option is selected, a new rollout appears in the Environment panel. This rollout includes settings for Brightness, Contrast, Exposure Value, and Physical Scale. You can also enable Color Correction, select a color, and select an option to Desaturate Low Levels. The Brightness and Contrast settings can range from 0 to 100. A Contrast value of 0 displays all scene objects with the same flat gray color, and a Brightness value of 100 displays all scene objects with the same flat white color. The Exposure Value can range from –5 to 5 and determines the amount of light that is allowed in the scene.

Another exposure control option is Linear Exposure Control. Although this option presents the same settings as the Automatic Exposure Control, the differences between the minimum and maximum values are a straight line across the light spectrum.

Tip The tricky part is to know when to use which Exposure Control. For still images, the Automatic Exposure Control is your best bet, but for animations, you should use the Logarithmic Exposure Control. Automatic is also a good choice for any scenes that use many lighting effects. The Linear Exposure Control should be used for low dynamic range scenes such as nighttime or cloudy scenes.

The Logarithmic Exposure Control option replaces the Exposure Value setting with a Mid Tones setting. This setting controls the colors between the lowest and highest values. This exposure control option also includes options to Affect Indirect Only and Exterior Daylight. You should enable the Affect Indirect Only option if you use only standard lights in the scene, but if your scene includes an IES Sun light, then enable the Exterior Daylight option to tone down the intensity of the light.

Cross-

Reference

You should always use the Logarithmic Exposure Control setting when enabling the advanced lighting features because it works well with the low-level light. You can learn more about the advanced lighting radiosity features in Chapter 29, “Advanced Lighting and Radiosity.”

Pseudo Color Exposure Control

As you work with advanced lighting solutions and with radiosity, determining whether interior spaces and objects have too much light or not enough light can be difficult, especially when comparing objects on opposite sides of the scene. This is where the Pseudo Color Exposure Control option comes in handy.

This exposure control option projects a band of colors (or grayscale) in place of the material and object colors that represent the illumination or luminance values for the scene. With these pseudo-colors, you can quickly determine where all the lighting is consistent and where it needs to be addressed.

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In the Pseudo Color Exposure Control rollout, shown in Figure 41-17, you can select to apply the colors to show Illumination or Luminance. You can also select to use a Colored or Grayscale style and to make the Scale Linear or Logarithmic. The Min and Max settings let you control the ranges of the colors, and a Physical Scale setting is included. The color (or grayscale) band is shown across the bottom of the rollout with the values for each color underneath.

Figure 41-17: The Pseudo Color Exposure Control rollout can display illumination and luminance values as colors.

When this exposure control is used, the associated render element is automatically set in the Render Elements rollout of the Render Scene dialog box. If the scene is rendered, then the appropriate (Illumination or Luminance) render element is also rendered.

Cross-	See Chapter 43, “Using Render Elements and Render Effects” for more on render elements.
Reference

Tutorial: Using the Logarithmic Exposure Control

As you start to use the new photometric lights, you may find it difficult to get the settings just right. The results are oversaturation or undersaturation, but luckily the Logarithmic Exposure Control can quickly fix any problems that appear.

To adjust the effect of a photometric light using the Logarithmic Exposure Control, follow these steps:

1.Open the Array of chrome spheres.max file from the Chap 41 directory on the CD-ROM.

This file contains lots and lots of chrome mapped spheres with advanced lighting enabled.

2.Choose Rendering Render (or press the F10 key) to open the Render Scene dialog box, and click the Render button.

It takes a while to render, but notice the results, shown on the left of Figure 41-18.

3.Choose Rendering Environment (or press the 8 key) to open the Environment & Effects dialog box. In the Exposure Control rollout, select Logarithmic Exposure Control from the drop-down list, and enable the Active and Process Background and Environment Maps options. Then click the Render Preview button.