Inside LightWave 3D v10: Lighting

This chapter is from the book

Inside LightWave 3D v10

Learn More Buy

This chapter is from the book

This chapter is from the book 

Inside LightWave 3D v10

Learn More Buy

Applying Lights in LightWave

You will encounter many types of lighting situations when creating your animation masterpiece. This next section steps you through a common lighting situation that you can use for character animation tests, product shots, or logo scenes.

Simulating Studio Lighting

One of the cool things about LightWave is that you don't have to be a numbers person to make things happen. You can see what's happening throughout the creation process from object construction to surfacing to lighting. Exercise 4.2 introduces you to basic three-point lighting often used in everyday video production. You can apply this lighting style to LightWave and create a photographer's backdrop (or cyc, short for cyclorama) to act as a set for your objects. Creating a set in LightWave is a good idea so that even simple render tests are not over a black background. By rendering objects on a set, you add more depth to your animation.

The goal of this project is to introduce you to a common lighting setup that can be useful in just about any type of render situation when simulating studio lighting. You'll use a premade scene from this book's DVD.

Exercise 4.2. Simulating Studio Lighting

1. In Layout, load the unlit_female_head.lws scene from this chapter's folder on the accompanying DVD (in the "3D_Content\Scenes\Ch4\" directory).

   This loads the multilayered object, which includes eight layers—all the parts of the model, from teeth to skin. The light box is a flat polygon that will be used to help light the subject. Figure 4.9 shows the loaded scene in Wireframe mode.

   

   Figure 4.9 A preexisting scene with one multilayered object, perfect for testing some lighting configurations.

2. Click the Lights button at the bottom of the Layout interface (or press Shift+L) to select the only light currently in the scene, which is generically named Light. (If the scene contained more than one light, you'd also need to select the one you want to work with from the Item drop-down.) This is a distant light and is not the most effective lighting. To see how it lights the scene, press F9 to render the current frame (Figure 4.10 on the next page).
   

   Figure 4.10 Pressing F9 lets you preview a render of the current frame. By default, the render isn't any different from what you see in Layout.

   To see the render when you press F9, be sure that you have Image Viewer selected for Render Display with a chosen resolution, or choose Render Frame from the Render drop-down.

3. The render looks flat and ordinary, and you need some definition from the background. Add a spotlight from the Add category in Layout, under the Items tab.
4. Name the light backlight, and position it up and behind the female head object. In the Light Properties panel, set the Light Intensity to 140%. You can select Lights at the bottom of the interface, and then press the p key to open the panel. Figure 4.11 shows the render, with the Light Properties settings. You can turn Shadows to Shadow Map within the Light Properties panel as well.
   

   Figure 4.11 Adding a kick light to the back of the model helps separate her from the black background.

   NOTE

   If you want to convert the Shadow Map Size to actual megabytes, square the size value, multiply by 4, and divide by 1,000. So, (2000 x 2000 x 4) ÷ 1000 = 16MB. That means a Shadow Map Size of 2000 will take an extra 16MB of memory for calculation.

   The trick to this simple setup is using bounce cards. In a real photography studio (such as www.AblanGallery.com) large softboxes are used for photographing people. In the 3D world, directional lights like spotlights can be harsh. But with a colored board, set to white or off-white, you can bounce light and softly diffuse the surface of the model.

   NOTE

   Three-point lighting is a common lighting setup used in many studios. It consists of a key light, which is the primary source of brightness; a fill light, which is less bright than the key and used opposite the key; and a backlight, sometimes referred to as a hair light, which is used to separate the subject from the background. You'll find a similarly set scene called studio_lit_female_head.lws on the book's DVD.

   If you view the scene from a Perspective view, you'll see two bounce cards. One is white and off to the right of the model. Its surface is bright white and has a Luminosity value. The other board is off-white and is used to bounce light underneath the model. But when you rendered before you didn't see the effect of these. That's because on their own, objects can't cast light. With Global Illumination turned on, they can.

5. In the Render tab, open Render Globals. In the Render Globals panel, click into the Global Illum tab and click Enable Radiosity. Press F9 again. Your model now looks completely different, and actually too lit! Figure 4.12 shows the render along with the Global Illumination settings.
   

   Figure 4.12 Turning on Enable Radiosity allows the bounce cards to cast a soft, diffuse light on the scene, but the scene is too bright with the existing spotlights.

6. Jump back to the Light Properties panel and bring the Light Intensity to 0% for both lights. Alternatively, you can deselect Affect Diffuse for each light and they won't affect the surface. However, other properties will still be affected, such as specularity.

   NOTE

   You can use shadow maps only with spotlights.

7. Press F9 to render again, and you'll see a much softer look to the model, but with a slight darkness on the left side. Figure 4.13 shows the render.
   

   Figure 4.13 Turning down the intensity of the existing light sources will help even out the values with radiosity applied.

   NOTE

   You can quickly choose different lights in the Light Properties panel by clicking the small arrow to the right of the Current Light drop-down list.

8. Select the back spotlight you created earlier. Clone it one time by pressing Control+C. Move this clone to the top front left of the female model. Set the Light Intensity value to 45% and press F9 to render. Ah! Now there are catchlights in the model's eyes, but a nice soft diffuse from the bounce card on the right. Figure 4.14 shows the render, along with the Perspective view to see the lighting setup.
   

   Figure 4.14 Adding a spotlight to fill the darker area of the model's face works well to enhance her surfacing, while the Enable Radiosity setting allows the bounce cards to fill in other areas.

Enhanced Lighting with HDR

Now that you have some basic lighting set up and can see how useful radiosity can be, it's easy to take your lighting a step further. HDR (High Dynamic Range) is a technique that allows you to use an image as a light source. However, HDR images hold more data within them than meets the eye. But LightWave can see what's there, so let's see how it works.

Exercise 4.3. Enhanced Lighting Setups

1. Continue from the previous scene, making sure Enable Radiosity is still selected in the Global Illum (Illumination) tab in the Render Globals panel.
2. From the Windows drop-down menu, choose Backdrop Options. This will open the Effects panel, with the Backdrop tab selected.
3. From the Add Environment drop down menu, select Image World. When the plug-in loads, double-click it to see the settings, as shown in Figure 4.15.
   

   Figure 4.15 Add the Image World plug-in from the Add Environment menu in the Backdrop tab of the Effects panel.

4. From the DVD included with this book, load the road.hdr image from the Light Probe Image selection. Figure 4.16 shows the image. Set the Heading Offset to 90. And then bring Brightness for the HDR image down to about 80%.
   

   Figure 4.16 An HDR image used for environmental lighting.

5. With the HDR image loaded, you don't need the other light sources. Go ahead and delete the extra spotlights, and make sure the main light has Affect Diffuse deselected in the Light Properties panel.
6. Next, delete the bounce card objects. Figure 4.17 shows Layout from a Perspective view with the changes.
   

   Figure 4.17 Layout in Perspective view with the bounce card objects deleted.

7. That's it! Instead of pressing F9 to render, turn on VPR from the top of the Layout interface, rather than Shaded Solid. Figure 4.18 shows the interface with VPR active and with the Image World settings.
   

   Figure 4.18 With an HDR image set in place through the Image World plug-in, the color values within the image light the scene entirely.

   HDR images are a remarkable way to light your scene, not only for ease of use, but more for blending your 3D object into a real world. The world around us has light of different temperatures bouncing and diffusing all over the place, and by using an HDR image in LightWave, you can mimic the real world.

Using Projection Images on Lights

LightWave's Projection Image feature is a useful lighting tool that mimics real-world lighting situations in which cookies or gobos are used to throw light onto a set. A gobo, also referred to as a cucoloris or cookie, is a cutout shape that is placed in front of a light, sort of like a cookie cutter. Certain areas of the gobo hold back light, whereas other areas let light through. In Exercise 4.4, you use a gobo that creates the look of light coming through trees.

Although the previous exercise was basic in design, it is the core lighting situation for many of your LightWave scenes. Perhaps with a slight variation, this basic three-point lighting scheme can be used for product shots, animated plays, logos, and much more. Things like simple stage sets, equipment, figures, generic objects, or any element can benefit from this type of lighting design. Of course, you are not limited to using just three lights for these types of situations. You can start with the basic three, and then add or remove lights to highlight certain areas, brighten dark areas, or use additional lights as projection lights.

The gobo image is nothing more than a Photoshop file of a black-and-white windowpane. Using a simple image-editing program, it was converted to grayscale mode, its contrast was boosted, and the image was blurred. When this image is applied to a spotlight, the white areas allow light to shine through, whereas the black areas do not. The blurring helps create a soft, less harsh look where the light falls off.

Exercise 4.4. Creating Gobo Lights

1. Continuing from the last project, use the same scene. Select the single spotlight left in the scene and name it Gobo Light or something similar. You can rename lights from the Light Properties panel. The idea is that you stay organized by identifying the lights properly as you set them up. Select the new spotlight and press 5 on the keyboard to switch to Light view.
2. At the bottom of the Light Properties panel, load the SixWindowCookie.tif image from the book's DVD.
3. Press 5 on the keyboard to jump to the Light view. There, you'll see the projection of the image through the light. The white areas will let light pass through, and the dark areas will hold it back. Blurring the image helps blend the transition. Figure 4.19 shows the shot.
   

   Figure 4.19 The SixWindowCookie.tif image in Light view.

4. Move the gobo light up and to the upper-right or upper-left side of the scene. Height doesn't matter too much; just be sure your projection will be able to hit the set. Point the light onto the floor, and be sure to create a keyframe for it at frame 0 to lock it in place.

   Remember, everything should have a keyframe at the first frame of your animation even if it is not moving. In this case, the first frame is 0.

   NOTE

   While you can't tell LightWave to create off-white lights by default, you can change multiple lights to off-white (or any other color) at the same time. Select all of the lights you want to adjust, and change the color settings in the Light Properties panel to affect all of the lights at once. In the same way, you can modify other light properties for all selected lights.

5. Make the new gobo light slightly off-white in color and set Light Intensity to anywhere from 40% to 60%.
6. After the image has been loaded, press F9 to render. You'll see what appears to be light through a window, across the face of the object. The light is now projected through the grayscale image, which you can see from Light view (see Figure 4.20). You can take a closer look at the gobo image in the Image Editor. Note that your image might appear slightly different due to variances in light placements.
   

   Figure 4.20 With the gobo image in place, you now see the shadows of a windowpane across the subject's face.

You can load this final scene into Layout from this book's DVD and check the final settings if you want. The scene is called studio_lit_female_head_enhanced.lws (in the "3D_Content\Scenes\Ch4\" directory). Take a look at it and modify it for your own scenes if you like.

Adding gobos is easy. But it's probably a more powerful feature than you realize. Creating a simple pattern on a set is nice, but you can accomplish much more with gobos:

• Use a grayscale image of tree branches to simulate shadows from a tree.
• Use color images for added dimension. Darker areas will hold back more light, and lighter areas will shine more light. For example, you can create the effects of light through a stained-glass window.
• Use softer, blurry images for added effects.
• Use animation sequences as projection images.
• Use imported movie files! Create real projected movies in your animation by projecting an AVI or QuickTime movie onto a movie screen in 3D.
• Create custom shapes and project them onto your set to create the look of light coming through a stage light projection system.