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CSS552: Programming Assignment #3

Shadow and Secondary Illumination

Due Time: Refer to the course web-site.

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Objective

The goals of this programming assignment are for us to implement, experience, and understand the global illumination effects: shadow computation, reflection, and very simple refraction.  Here are more details.

Approach

Please refer to my solution. Here are the command files (with sample test cases). You should download and unzip both of these files, then double click on RTViewer to run the sample program. Notice that in this version of the ray tracer you are to extend your Phong illumination model from mp2 to include support for shadow, reflection, and the simplest support for refraction computation. Please download this starter project (my mp2 solution) and unzip the source code. Here are some important hints to the source code:

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The RayTracer Project: RTCore_Init.cs

Notice the new loop to initialize all lights. This is where shadow depth map should be computed (before rendering computation actually begins!).

RTLightType:

• InitiailizeLight: Notice RTLightType_Spot: now override this function and attempts to "initialize". If depth map is switched on, you should compute the map.
• PercentVisible(visiblePt, exceptGeomIndex, sceneDatabase): This function should determine if the light source is blocked from "visiblePt", with the exception of exceptGeomIndex (why?), and if so, what "percentage" of the light is blocked (when depth map filtering is enabled).
• DistanceToLight(visiblePt): This function should return the distance between the visiblePt and the light position. This is to avoid the shadowing of objects behind the light source problem (refer to the ppt at the end of this assignment specification). How would you handle the situation when a light does not have a position (i.e., Direction Light)?

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Credit Distribution

Here is how the credits are distributed in this assignment:

1. 15%: Reflection

2. 20%: Refraction

3. 25%: Shadow: Ray trace point sampled
• (10%) Point light shadow
• (10%) Directional light shadow
• (10%) Spotlight shadow
4. 35%: Shadow Depth Map
• (10%) Proper computation of the map with visible ray casting (like MP1 all over again!)
• (15%) Proper use and lookup of the depth map during ray tracing
• (10%) Proper support for depth map filtering
  
5. 5%: Cleanup MP2 GUI check boxes
• Force you to take a little look at the GUI aspect of our system. You only need to figure out what are the lines to delete.
  
  
6. 5%: Proper submission
• No useless files
• Proper name of zip file.

Extra Credits

• 3pt: Support specification of shadow color where your user can say they want shadow to be e.g., in color of red (instead of black).

Interesting (or not) potential bug

· Refer to this ppt, light source closer than object!

This programming assignment will count 15% towards your final grade for this class.