Speeding Up Rendering

Set up the scene by doing one of the following:

• Open my_library.max, which you created in the previous lesson.

• From the \tutorials\radiosity\ directory, open library_with_radiosity.max.

  If you see the File Units: Mismatch dialog, choose the option Adopt The File's Unit Scale. This will change your system unit, so be sure to reset your system unit after completing this tutorial.

  To reset your system unit, go to the Customize menu and choose Units Setup > System Unit Setup > System Unit Scale > Inches.

  Note: All the files necessary to do the tutorials can be found on the program disc. Before doing the tutorials, copy the \tutorials directory from the disc to your local program installation.

Turn off antialiasing and maps:

1. Choose Rendering > Render.

   The Render Scene dialog is displayed.

2. Go to the Renderer panel. On the Default Scanline Renderer rollout, in the Antialiasing group, turn off Antialiasing. In the Options group, turn off Mapping as well.

3. Click Render.

   The rendering goes quickly, but edges are jaggy, and the rendering doesn't show details provided by texture maps.

   

   Note: The radiosity in this scene was created with the option Re-Use Direct Illumination From Radiosity Solution. Because of this, the shadows in the scene come from the radiosity mesh. (Sometimes shadows from the mesh can be grainy and inaccurate.) If you had generated radiosity with the option Render Direct Illumination instead, then turning off Shadows in the Options group would also help speed up render time.

Using a layer to hide objects:

Hiding more complicated objects, especially if they aren't essential to an overall visualization, is another way to speed up rendering time.

1. On the Layers toolbar, click the downward-pointing arrow at the left of the Layer List to display the list.

   (If the Layers toolbar is not visible, right-click a blank area of another toolbar, and choose Layers from the pop-up menu.)

2. Click to turn off the Visible icon of the Furniture layer.

   

   The eyeball icon indicates whether a layer is on or off.

   The bookcase, chairs, and end tables are now hidden in the scene.

3. Click Quick Render.

   The scene renders without the geometry of chairs, tables, and bookcase.

   

   Note: The shadows of the furniture, especially the bookcase, are still there. This is a by-product of reusing direct illumination from the radiosity mesh.

Use the “Draft” presets:

The Render Scene dialog provides preset parameters for different levels of rendering.

1. Turn the Furniture layer back on.

2. At the bottom of the Render Scene dialog, choose viz.scanline.radiosity.draft from the Preset drop-down list.

   A Select Preset Categories dialog is displayed.

3. On the Select Preset Categories dialog, Ctrl+click to remove the highlight from Environment and Raytracer. Make sure Default Scanline Renderer and Advanced Lighting are highlighted, then click Load.

   An alert warns you that this preset will recalculate the radiosity solution. Click Yes.

4. Go to the Advanced Lighting rollout, and click Start to recalculate radiosity using the preset values.

   This doesn't take long, because the draft preset specifies a relatively low Initial Quality value: 10.0 percent.

5. Click Render.

   This time there is a bit of a delay. The draft preset for radiosity has Render Direct Illumination chosen. Even so, it doesn't take too long to get an overall idea of how a polished version of the rendering might look.

Save your work:

• Choose File > Save As. In the file dialog, name the file my_radiosity_renderings.max, and then click Save.