CS 6620 - Fall 2012 - Ray Tracing for Graphics

Project 9 - Soft Shadows and Glossy Surfaces

In this project we will add support for soft shadows and glossy reflections to our ray tracers.

Requirements

• Implement glossy reflections.
• Implement soft shadows for area lights.
• Render images showing your results.

XML Scene Format

In the XML scene format we specify glossy reflections/refractions by adding a "glossiness" value for the "reflection" or "refraction" tag of the Blinn material. If the glossiness is not specified, it should be regarded as zero, which means no glossy reflections/refractions. Notice that the "glossiness" value for the "reflection" tag is separate from the "glossiness" of the Blinn shading.

<material type="blinn" name="ground">
   <diffuse r="0.3" g="0.3" b="0.3"/>
   <specular value="0.1"/>
   <glossiness value="50"/>
	<reflection value="1.0" glossiness="0.5"/>
</material>

We specify area shadows by adding a "size" value to point lights. This size value effectively converts the point light to a spherical area light.

<light type="point" name="pointLight">
	<intensity value="1.0"/>
	<position x="-50" y="-100" z="50"/>
	<size value="5.0"/>
</light>

You can use this test scene to verify that your implementation is correct.

Resources

Here is an example implementation of the XML parser using TinyXML.

Optional Feature Suggestions

• Implement glossy refractions.
• Use importance sampling for glossy reflections/refractions.
• Implement area lights for shading.
• Use a Quasy Monte-Carlo sequence for glossy reflections/refractions as well as area lights.

Student Project Pages

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