3ds Max 2012 Bible - Kelly L. Murdock [475]
Tip
Although this modifier was created to help with radiosity solutions, it also helps with other commands that require regular mesh faces, such as the Boolean and Terrain compound objects. •
The Parameters rollout includes a Size value that determines the density of the mesh. The lower the value, the denser the mesh and the better the resulting radiosity solution, but the longer the solution takes. This same Subdivision Size setting also can be found (and set globally) in the Radiosity Meshing Parameters rollout of the Advanced Lighting panel. It is also found in the Advanced Lighting panel of the Object Properties dialog box. Figure 45.9 shows a simple cube with the Subdivide modifier applied and the Size value set to (from left to right) 50, 30, 25, 20, and 12.
Tip
If you drag the Size value, you'll probably want to set the Update option to Manual or you'll find yourself waiting while Max computes some seriously dense mesh, or you can just disable the Display Subdivision option. •
FIGURE 45.9
The Subdivide modifier changes all mesh faces into regularly shaped triangular faces.
Tutorial: Preparing a mesh for radiosity
When it comes to meshes that have long, thin, and irregular faces, you don't have to look any further than Boolean compound objects. These objects typically are divided along strange angles, producing ugly meshes. The good news is that these meshes are easy to subdivide.
To subdivide an irregular mesh in preparation for a radiosity solution, follow these steps:
1. Open the Boolean object.max file from the Chap 45 directory on the CD.
This file includes two copies of a Box object with an arch shape Boolean subtracted from it.
2. Select the top object, and choose the Modifiers⇒Radiosity Modifiers⇒Subdivide menu command.
This applies the Subdivide modifier to the object.
3. In the Parameters rollout, select the Manual update option, set the Size value to 5.0, and click Update Now.
If the Display Subdivision option is enabled, then the changes are visible in the viewport.
4. Open the Advanced Lighting panel with the Rendering⇒Radiosity menu command (or press the 9 key). Select Radiosity from the drop-down menu.
Figure 45.10 shows the two objects with and without the Subdivide modifier applied. The top object is ready for a radiosity solution.
FIGURE 45.10
Subdividing an irregular mesh prepares it for radiosity lighting.
Painting with light
The Light Painting rollout (found in the Advanced Lighting panel of the Render Scene dialog box), shown in Figure 45.11, includes buttons for Adding Illumination, Subtracting Illumination, and Picking an Illumination value from the scene. Using these tools, you can paint lighting on the objects in the scene. The Clear button removes all the changes you've made using the Light Painting tool.
FIGURE 45.11
Because lighting is saved as a light map, you can add or subtract light from the scene using a brush tool.
Rendering parameters and statistics
Settings in the Rendering Parameters rollout (shown in Figure 45.12) are used during the rendering process. The Re-Use and Render Direct Illumination options give you the chance to reuse the existing radiosity solution when rendering or to recalculate it as part of the rendering process. This can save some time during rendering.
FIGURE 45.12
The Rendering Parameters and Statistics rollouts offer rendering options and statistics for radiosity solutions.
The Regather Indirect Illumination option enables a Light-Tracer-like step along with the radiosity solution and produces an image that has the best of both solutions. The regathering options are the same as those defined for the light tracer.
The Statistics rollout includes information about the radiosity process. Using this information, you can judge whether the settings are too high or too low.
Tutorial: Lighting a house interior with radiosity
Radiosity works best in indoor scenes or scenes that