3ds Max 2012 Bible - Kelly L. Murdock [480]
Note
The Photographic Exposure Control is available only for the mental ray render engine. •
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.
FIGURE 46.2
The Photographic Exposure Control rollout works with real-world camera settings.
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 46 directory on the CD.
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 in Figure 46.3.
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.
4. In the Logarithmic Exposure Control rollout, set the Brightness value to 60, set the Contrast value to 100, and enable the Desaturate Low Levels option.
5. In the Render Scene dialog box, click the Render button again to see the updated rendering.
The image on the right in Figure 46.3 shows the rendered image with exposure control enabled.
FIGURE 46.3
This rendered image shows an image before and after exposure control was enabled.
Creating Atmospheric Effects
The Environment and Effects dialog box (keyboard shortcut, 8) contains rollouts for adding atmospheric effects to your scene, but the first question is where. Atmospheric effects are placed within a container called an Atmospheric Apparatus gizmo, which tells the effect where it should be located. However, only the Fire and the Volume Fog effects need Atmospheric Apparatus gizmos. To create an Atmospheric Apparatus gizmo, select Create⇒Helpers⇒Atmospherics and choose the apparatus type.
The three different Atmospheric Apparatus gizmos are BoxGizmo, SphereGizmo, and CylGizmo. Each has a different shape similar to the primitives.
Working with the Atmospheric Apparatus
Selecting a gizmo and opening the Modify panel reveal two different rollouts: one for defining the basic parameters such as the gizmo dimensions, and another labeled Atmospheres & Effects, which you can use to Add or Delete an Environment Effect to the gizmo. Each gizmo parameters rollout also includes a Seed value and a New Seed button. The Seed value sets a random number used to compute the atmospheric effect, and the New Seed button automatically generates a random seed. Two gizmos with the same seed values have nearly identical results.
Adding effects to a scene
The Add button opens the Add Atmosphere dialog box, where you can select an atmospheric effect. The selected effect is then included in a list in the Atmospheres & Effects rollout. You can delete these atmospheres by selecting them from the list and clicking the Delete button. The Setup button is active if an effect is selected in the list. It opens the Environment and Effects dialog box. Adding Atmospheric Effects in the Modify panel is purely for convenience. They can also be added using the Environment and Effects dialog box.
In addition to the Modify panel, you can add atmospheric effects to the scene using the Atmosphere rollout in the Environment and Effects dialog box, shown in Figure 46.4. This rollout is pretty boring until you add an effect to it. You can add an effect by clicking on the Add button. This opens the Add Atmospheric Effect dialog box, which includes by default four atmospheric effects: