2010

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The rendered image shows the following:
A translucent bottle with apples beside it casting shadows towards
the rear of the scene. Notice how the shadows appear when raytrace
rendered.
The distortion of the table surface in the translucent glass effect based
on the refractions and reflections.
A dark region on the surface of the bottle. This results from the bottle
reflecting the empty black area of the scene in front of it.
In the next section, you turn on the caustics rendering attributes and render
the scene.
Render the scene using caustics
To render using caustics you need to turn on specific settings or attributes.
There are two sets of caustic-related attributes that you must initially set.
Turn on the caustics-related rendering attributes using the Render Settings
window.
Turn on the caustics-related lighting attributes using the Attribute Editor.
You initially render the scene using these attributes at their default settings
to see how they affect the rendered image and then compare it to the previous
raytrace rendering. As you gain more experience rendering with Caustics you
will better understand what settings to initially use.
To turn on the caustics preset settings
1 In the Render Settings window, select the Quality tab and set the Quality
presets setting to PreviewCaustics.
This turns on the presets that control the quality of the caustics.
2 Close the Render Settings window.
Mental ray for Maya uses photons to simulate the caustic effects in a scene.
Photons are small packets of energy emitted from a light source into the scene.
The photons travel throughout the scene, refracting through transparent
objects or reflecting off reflective surfaces. The renderer keeps track of the
526 | Chapter 9 Rendering