[SOLVED] CS4247 Assignment 4

Assignment Overview

You are provided with an incomplete C/C++ program that implements the progressive refinement radiosity algorithm

Task 1
 Complete the program

 Generate a radiosity solution for the sample input scene Task 2

 Create a new input scene model
 Generate a radiosity solution for the new scene

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Learning Objectives

 Implementing the Progressive Refinement Radiosity Algorithm  After completing the assignment, you should have learned

 How to use the Hemicube algorithm to estimate form factors:

•   How to compute delta form factor for each pixel on the hemicube
•   How to set up OpenGL views to project the scene onto the faces of the hemicube
•   How to use the item buffering technique to identify the patch that occupies a pixel

   How the progressive refinement radiosity algorithm works:

•   How to “shoot” light power from a shooter patch to the gatherer

  patches, and update the radiosity values of these patches

•   How to update the unshot power of a shooter patch with the new

  power received by its child gatherer patches

•   How to terminate the progressive refinement radiosity computation

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What Are Provided (1)

Download the file cs4247_2021S2_assign4_todo_(win-vs2017).zip from the Assignments folder in LumiNUS Files

The ZIP file contains a Visual Studio 2017 solution file assign4.sln. The solution has three C/C++ projects

 QuadsViewer
 RadiositySolver  RadiosityViewer

 Tip: In Visual Studio, to make a project the default project to be built and run, you can right-click on the project name in the Solution Explorer, and select “Set as StartUp Project”

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For Windows

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What Are Provided (1)

Download the file cs4247_2021S2_assign4_todo_(mac-xcode).zip from the Assignments folder in LumiNUS Files

The ZIP file contains the Xcode project assign4.xcodeproj, which has the following three C/C++ targets

 QuadsViewer
 RadiositySolver  RadiosityViewer

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For

macOS

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What Are Provided (2)

 QuadsViewer is a completed (old-style) OpenGL application that lets you preview the input scene model and check the subdivision of the input quads into smaller “shooter” quads and even-smaller “gatherer” quads

 The default input scene model file is model.in

 Gatherer quads are obtained by subdividing shooter quads

•   Press “m” to cycle through display of the input quads, the shooter quads, and the gatherer quads
•   In quadsviewer.cpp, the size of the shooter and gatherer quads are controlled by the values of maxShooterQuadEdgeLength and maxGathererQuadEdgeLength respectively

   These two values are from the input scene model file model.in

   radiositysolver.cpp also uses these two values for the same purpose

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What Are Provided (3)

 RadiositySolver is the incomplete program that

 Reads the input scene model from model.in

 Subdivides the input quads into “shooter” and “gatherer” quads

 In radiositysolver.cpp, the size of the shooter and gatherer quads are controlled by the values of maxShooterQuadEdgeLength and maxGathererQuadEdgeLength respectively

 These two values are from the input scene model file model.in  Computes a radiosity solution for the scene

 This step is the part to be completed
 Computes vertex radiosities from the patch radiosities

 This step can take very long to run, so you should first test your radiosity algorithm implementation with a model with not too many gatherer quads

 Outputs the model with radiosity solution to the file model.out
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What Are Provided (4)

 RadiosityViewer is a completed (old-style) OpenGL application that lets you view the model output by RadiositySolver

 Reads in a model with radiosity solution from file model.out  Performs simple tonemapping to map radiosity values to

displayable color values (i.e. to R, G, B values from 0.0 to 1.0)

 Renders the polygons using the tonemapped radiosity values as vertex colors

 You can try the viewer on the given sample model file cornell_box.out

 First, copy cornell_box.out to the file model.out

 Note that the sample cornell_box.out has been “watermarked” with some bright and dark patches — your radiosity solution for cornell_box.in should not have those

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Task 1

 Complete only the source file radiositysolver.cpp, which is part of the RadiositySolver project

•   Complete the code at places marked “WRITE YOUR CODE HERE”
•   You can add additional functions to the file
•   Use good coding style and document your code

  adequately (otherwise marks deducted)

•   Study the files quadmodel.{h,cpp} to see how the scene model and its subdivided quads are represented
•   You can make use of helper functions found in common.h and vector3.h

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Task 1 (continue)

 Test your program on the provided sample input scene model cornell_box.in

•   Before running your RadiositySolver, copy cornell_box.in to the file model.in
•   After running your RadiositySolver, copy the output file model.out to cornell_box_my.out

   View your radiosity solution model.out using RadiosityViewer (in non-wireframe mode) and capture three different snapshots

•   On Windows 10, you can use the Snip & Sketch tool (press Win + Shift + “S”) to take a snapshot of the window and save the image
•   Use the default window size
•   Save the three snapshots to image files

   cornell_box_1.png  cornell_box_2.png  cornell_box_3.png

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Task 1

 RadiositySolver uses to the Progressive Refinement Radiosity algorithm to compute patch radiosity of each gatherer quad

 Pre-compute the delta form factors on the top face (already done) and side faces of the hemicube

 Note that top hemicube face has same pixel resolution as the default window size (always a square)

 Progressive Refinement Radiosity loop

•   Find the shooter quad with the greatest unshot power
•   Use a hemicube to compute form factors from the shooter quad to each of the gatherer quads
•   Update the radiosity of each of the gatherer quads
•   Update the unshot power of each shooter patch with the new power

  received by its child gatherer patches

•   Terminate loop if max iterations is reached

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RadiositySolver

Explained

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Task 2

Create a new scene model

•   Study the sample scene model cornell_box.in to find

  out the input model file format

•   Name your new scene new_model.in
•   Run your RadiositySolver program on new_model.in to output new_model.out
•   View new_model.out in RadiosityViewer and capture three different snapshots

   Use the default window size
   Save your snapshots to image files

   new_model_1.png  new_model_2.png  new_model_3.png

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What to Submit

Only the following 10 files

 Task 1

 radiositysolver.cpp

 cornell_box_my.out

cornell_box_1.png, cornell_box_2.png, cornell_box_3.png

 Task 2
 new_model.in
 new_model.out
new_model_1.png, new_model_2.png, new_model_3.png

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How to Submit

Put only the required files in a single ZIP file
Name your ZIP file your-student-number_assign4.zip

 e.g. A0123456X_assign4.zip
Submit your ZIP file to the Assignment 4 Submission

folder in LumiNUS Files

 Folder will close at the deadline
 You may upload your ZIP file multiple times, but we take

the latest

 Please delete your older versions

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Other Requirements

 Programming languages and APIs

 C / C++
 OpenGL 1.1 (old-style OpenGL; no shader)  GLU & GLUT / FreeGLUT
 No other third-party APIs are allowed

 Platform

•   You can develop your program on any OS and IDE
•   However, the final submitted version must be compilable/buildable in Microsoft Visual Studio 2017