<em>Poser 8 Revealed</em>: Adding Scene Lighting - Part 1

After you spend time posing your figure and positioning props and cameras, you’re ready to add lights to your scene.  Poser is smart enough to include and enable several lights by default, but these lights provide the most basic scene lighting. Understanding the basics of lighting design will help as you position and configure lights to create a unique look.

All lights within the scene can be controlled using the Light Controls. The Light Controls let you change the position, color, number, and intensity of the scene lights. You can also change the light’s parameters and properties using the Parameter dials in the Parameters/Properties palette. If you don’t know where to start in configuring your lights and cameras, you can look in the Library palette for several examples of lighting presets that can help you as you start out.

Poser includes several light types, including Spot, Infinite, Point, and Image-Based Lights. Lights can also be set to cast shadows. Shadows can be either raytraced shadows with sharp edges or depth-map shadows that are more blurred. The Properties palette also includes options to enable ambient occlusion, which can be used in place of shadows to add depth to the scene objects; and Attenuation, which defines the falloff of the light intensity over distance.

Using the Material Room, you can enable some special effects for lights such as projecting lights. Poser also includes some specialized features that let you point lights at specific items in the scene. For example, you can point spotlights at a figure’s head or hands to always keep the figure lighted as it moves during an animation.

Image-based lights provide a way to create a realistic lighting environment by wrapping a specialized image around the scene. The image that is wrapped is called a light probe and it includes a broad range of light sources from a sampled environment.

Learn Basic Lighting Techniques
Poser’s default lighting setup is good for emphasizing poses, but understanding some of the basics of lighting design can help better establish the mood of your scene.

Using 3-Point Lighting
The most popular method for lighting a scene is called 3-point lighting design. This design uses three lights[md]a key light, a back light, and one or more fill lights. The key light is the main light source for the scene. It is typically positioned at 45 degrees from the horizon and off to the side to shine down at an angle. The key light should also be the only light that is set to cast a shadow. It should also be the most intense light in the scene.

The back light is positioned behind the scene objects where it doesn’t shine into the camera. It is used to highlight the silhouetting edge of the scene characters. The intensity of the back light should be about half the intensity of the key light.

The fill lights are positioned at ground level in front of the scene and used to highlight and add depth to the scene forms. There can be several fill lights depending on how the scene objects are positioned, but their total intensity shouldn’t exceed half of the intensity of the key light. Figure 7-1 shows the default figure, first with only the key light, and then with the key and back lights, and finally with key, back, and fill lights.

Creating a Rim Light
Rim lights are used to create a silhouetting effect. They are created by positioning a light aimed at the current camera and positioning the main character of the scene between the light and the camera. The result is to highlight the outer rim of the character.

Using Underlighting
If you position the key light underneath the main figure and point it upward, you’ll get an unnatural effect that casts shadows upward much like holding a flashlight under a person’s chin. This lighting technique is often used in horror films to create a sinister, evil-looking character, as shown in Figure 7-2.

Using Light Color
Light color can dramatically change the mood of a scene. Warm colors such as yellow, orange, and red can create a feeling of warmth and excitement, but cool colors like green, blue, and purple denote a calmness and subdued mood.

Light color can also be used to establish where the scene takes place. Bright yellow lights are useful for daytime outdoor scenes, softer blue lights are good for creating moonlight, red and orange lights can create the glow of firelight, and white lights with a touch of blue are useful for simulating indoor fluorescent lights.

 

Establish 3-Point Lighting
1.         Open Poser with the default mannequin visible.

 

2.         Select the default light in front of the character and increase its intensity slightly.

3.         Select the back light and drag it so it points downward on the figure from above. In the Properties palette, disable Shadows for this light.

4.         Select the fill light to the side of the Light Controls and decrease its Intensity. Then disable its Shadows in the Properties palette.

The 3-point lighting design gives a good sense of depth and volume to the figure, as shown in Figure 7-3.

5.         Select File, Save As and save the file as 3-point lighting.pz3.

 Work With Lights 
If a scene contained no lights, none of the scene items would be visible when rendered, but Poser has three lights that are enabled by default. You can easily add more light sources to the scene. Poser works with four light sources[md]infinite lights, spotlights, point lights, and diffuse image-based lights (IBLs).

Learning the Light Types
Infinite lights shine from a distance so all its rays are parallel when they strike the scene objects. This causes all scene elements to receive an equal amount of light regardless of their distance from the light source. All objects that are lit by an infinite light will have parallel shadows.

Spotlights are focused, casting light only to those scene objects that are within the cone of influence; objects farther away receive less light than closer objects. Point lights cast light in all directions from a single point such as a light bulb or a candle in a room. Diffuse image-based lights (IBL) define the scene lighting by building an image of the scene that holds all the lighting information.

 When using point lights and diffuse IBL lights, realistic shadows can be computed only using raytracing.

Creating New Lights
All scene lights are displayed within the Light Controls. New lights can be created by clicking the Create Light button. By default, the Create Light button creates a spotlight, but you can change the type of light using the options in the Properties palette. Poser lets you switch easily between the various light types. You can select the type of light to create if you right-click on the Create Light button and select the light type from the pop-up menu or use the Object, Create Light menu.

Using the Light Controls
The Light Controls offer a convenient way of creating and positioning lights, and setting light properties. To open the Light Controls palette, select Window, Light Controls. The Light Controls palette, shown in Figure 7-4, include a large sample sphere in the center that shows the lighting effects; surrounding it are three smaller circles. These smaller circles are the lights. You can change their locations by dragging them about the larger sphere. When you select a circle representing a light, controls for changing its intensity, color, and properties appear within the Light Controls palette. There are also buttons for removing the selected light and creating new lights.

If you click on the title of the Light Controls, you can access a pop-up menu of options. Using these pop-up menu options, you can select a specific light, as well as create and delete lights and access the Properties palette for the selected light. There are also two positioning mode options: Rotate and Revolve.

The default mode is Revolve. Dragging the smaller spheres in the Light Controls around the larger sphere with this mode enabled orbits the selected light about the larger sphere, thus changing its position. Dragging the smaller spheres with the Rotate mode enabled keeps the light in its current position, but rotates it about, which changes where it is aiming.

 The Rotate mode is only available when a spotlight is selected.

 

Changing Light Color
When a light is selected, you can click on the colored dot beneath the Light Controls or click on the Color button in the Properties palette to open the color selector dialog box where you can choose a different light color.

 When a color selector dialog box is open, you can select any color currently visible on the computer whether it is within the current interface or from another application.

Selecting and Positioning Lights
You can select lights by clicking their circular icons in the Light Controls, by selecting a light from the Actor List located at the top of the Document Window or in the Parameters palette, or by choosing a light from Hierarchy Editor. When a light is selected, an indicator of the light, shown in Figure 7-5, becomes visible within the Document Window. You can position lights by dragging their circular icons with the Light Controls or by dragging their indicator in the Document Window using the Editing Tools. Each indicator in the Document Window is different depending on the light type that is selected. You also can position lights using the parameter dials found in the Parameters palette.

 When the spotlight type is selected, the parameter dials include values for setting the spotlight’s cone distance and angle.

Setting Light Properties
You can set several light properties in the Light Controls, but an extended set of properties is available in the Properties panel, as shown in Figure 7-6. The Name field lists the light's name, which is simply Light and a number by default, but you can type a new name.

The Preview panel in the Document Window can display real-time lighting effects for up to eight lights. By default, the eight brightest lights are displayed, but you can selectively set which lights are displayed by enabling the Include in OpenGL Preview option.

 New Poser 8 Feature
The Include in OpenGL Preview option is new to Poser 8.

The Visible property makes the visual icon of the light appear in the Document Window, the Animating property enables the light to be animated, and the On property turns the light on and off. The Properties palette also includes a set of radio buttons for selecting the light type and controls for configuring the shadows, ambient occlusion and attenuation. Shadows and ambient occlusion is covered in the next section.

Setting Light Attenuation
For Spot and Point lights, you can select an Attenuation setting. This setting controls how the intensity of the light decreases the further you move from the light source. This is a realistic effect that occurs in real-life. The options include Constant, Inverse Linear, and Inverse Square. The Constant option has no decrease and works just like lights in previous Poser versions; the Inverse Linear option decreases linearly with distance; and the Inverse Square option decreases exponentially so that objects close to the light source get much more light than those further away. Figure 7-7 shows a single point light with each of the attenuation options enabled.

 New Poser 8 Feature
The various light attenuation options are new to Poser 8.

Setting Light Parameters
In addition to the settings in the Properties palette, there are several more values in the Parameters palette for controlling lights. For Spot and Point lights, you can set the Distance Start and Distance End values, which denote the distance from the light’s center where the light starts to decay and the distance where the light has diminished to zero. For spotlights, you can also set Angle Start and Angle End values, which are the strength of the light at the cone’s point and the strength of the light at the end of the cone.

The Parameter palette also includes settings for controlling the intensity of the enabled shadows with the Shadow parameter. A value of 0 turns off shadows and higher values gradually darken the shadow until a value of 100, which is maximum. The Map Size is used to specify the size of the bitmap in pixels of the shadow map. Larger shadow maps have a finer resolution, but require more memory.

The Red, Green, Blue, and Intensity values set the light’s color and power. These parameters work the same as the settings found in the Light Controls.

Pointing Lights at Objects
Lights can also be set to point specifically at an object in the scene using the Object, Point At command. This causes the Point At dialog box, shown in Figure 7-8 to appear where you can select the point at object. Once a point at object is selected, the light continues to point at the selected object even as the light is moved throughout the scene. To remove the Point At link between an object and a light, select the Object, Point At command again and choose the None button.

Parenting Lights
Another way to control lights is to parent the lights to a scene object. This is accomplished by clicking on the Set Parent button in the Properties palette or by selecting the Object, Change Parent menu command. Once a light is parented to a scene object, it moves with the object as the object’s position changes in the scene. The parented relationship is also shown in the Hierarchy Editor. To unparent a light, simply select the Universe object as its new parent.

 Only Spot and Point lights can be parented.

  

Create and Position a Spotlight
1.         Open Poser with the default mannequin visible.

 

2.         Select each of the light circles in the Light Controls and click the Delete Light button to remove the default lights. Click OK in the Delete confirmation dialog box that appears.

3.         Click the Create Light button  in the Light Controls.

A new light circle is added to the Light Controls and a spotlight indicator appears in the Document Window.

4.         Drag the light circle in the Light Controls to roughly position the new spotlight above the scene figure.

5.         Drag the Move XZ control in the Camera Controls to zoom out the scene until the spotlight indicator is visible in the Document Window.

6.         Select Window, Parameter Dials to open the Parameters palette, if it isn’t already open, and set the Angle End value to 30.

7.         Select the main spotlight object from the Actor List at the top of the Document Window.

8.         Select the Object, Point At menu command.

9.         In the Point At dialog box that appears, select the Head object and click the OK button.

10.         Select and move the spotlight about the scene.

The spotlight points at the head object regardless of where it is moved within the scene, as shown in Figure 7-9.

11.         Select File, Save As and save the file as Head spot light.pz3.

Kelly L. Murdock has more than 15 years experience in the computer graphics arena, especially in the area of 3D graphics. Included in the experience is a variety of tasks from high-end CAD product design and architectural pre-visualization to virtual reality and games. Kelly is best known for his international best-selling books on graphics including the 3ds max Bible, Illustrator Bible and Naked Maya. He also is the author of Poser 6 Revealed and Poser 7 Revealed as well as Edgeloop Character Modeling for 3D Professionals. Kelly currently works as a freelance designer for Logical Paradox Design, a company that he founded with his brother.