In the latest excerpt of Poser 7 Revealed, Kelly L. Murdock explains how to work with default lights and how to add new light sources to a scene.
This is the next in a new series of excerpts from the Thomson Course Technology book Poser 7 Revealed: The e frontier Official Guide. In the next few months, VFXWorld readers will develop the skills needed to create, render and animate scenes and projects using the amazing tools offered by Poser 7. We will offer step-by-step tutorials for each task, followed by projects that allow readers to apply each new skill.
What You'll Do
In this lesson, you learn how to work effectively with lights.
If a scene contained no lights, all scene items wouldn't be visible, 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 -- 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. 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) lights define the scene lighting by building an image of the scene that holds all the lighting information.
Note: When using point lights and diffuse IBL lights, realistic shadows can be computed only using ray tracing.
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.
New Poser 7 Feature:
The ability to create each of the different light types using the Object menu is new to Poser 7.
Using the Light Controls
The Light Controls offer a convenient way of creating and positioning lights, as well as setting light properties. To open the Light Controls, select Window, Light Controls. The Light Controls, shown in Figure 1, 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. 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 modes.
The default mode is Revolving. 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.
Note: 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 a color selector dialog box where you can choose a different light color.
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 by choosing a light from the Hierarchy Editor. When a light is selected, an indicator of the light, shown in Figure 2, 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.
Note: 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 3. 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 Visible property makes the visual indicator 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 shadows and ambient occlusion.
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 Parameters 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 4, 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.
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.
Note: Only Spot and Point lights can be parented.
Create and Position a Spotlight
- 1. Open Poser with the default man 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 5.
11. Select File, Save As and save the file as Head spot light.pz3.
Find out more about how to put the power of Poser 7 to work as you learn how to use the new Talk Designer to automatically sync facial animations to an audio track, combine the power of Poser 7 with other software packages, create new motions using the new animation layers feature and much more. Check back to VFXWorld frequently to read new excerpts.
Poser 7 Revealed: The e frontier Official Guide by Kelly L. Murdock. Boston, MA: Thomson Course Technology, 2007. 592 pages with illustrations. ISBN 13: 978-1-59863-296-5; ISBN 10: 1-59863-296-5 ($29.99).
Kelly L. Murdock has a background in engineering, specializing in computer graphics. He has worked on several large-scale visualization projects, created 3D models for several blockbuster movies and has worked as a freelance 3D artist and designer. Murdock is the author or co-author of several books, including seven editions of the 3ds Max Bible, two editions of the Illustrator Bible, Adobe Creative Suite Bible, Maya 7 Revealed, LightWave 3D 8 Revealed and Poser 6 Revealed. He works with his brother at his co-founded design company, Logical Paradox Design.