codencandy/cornellbox

Cornell Box (originally from Robert Hodgin) to demonstrate some 3D rendering concepts

Cornellbox inspired by Robert Hodgin

This project rebuilds the base of an art project originally created by Robert Hodgin https://roberthodgin.com

Just search on YouTube for Robert Hodgin Eyeo2012 to watch a full video showcasing his creation. The source code is available on GitHub https://github.com/flight404/Eyeo2012

Topics covered in this project

• creating a window
• integrating a user interface framework (ImGui)
• hardware accelerated rendering with Metal
• fake ambient occlusion shadows
• matrix transformations (scale, move, rotate)
• perspective projection
• resizeable window
• camera concept including rotation and movement

What you need

All you need to follow along or just build this project is:

• Visual Studio Code
• XCode command line tools (not XCode itself)
• cloc to measure lines of code

VS Code extensions

The following VS Code extensions are also partly necessary:

• C/C++ Extension Pack
• C/C++ Clang Command Adapter
• Metal Shader Extension for Visual Studio Code

How to build and run

In order to build the project clone this repository and update the submodule libs/imgui with
git submodule update --init

Then run sh build.sh ALL once to get ImGui to build into an object file. Every subsequent build only requires
sh build.sh

In order to run execute
./cornellbox

In case you close the user interface F1 brings it back.

Further links

Paper explaining quarternions: https://danceswithcode.net/engineeringnotes/quaternions/quaternions.html

An excellent explanation about how to construct a prespective projection matrix can be found here:
https://www.youtube.com/watch?v=EqNcqBdrNyI

Immediate mode user interface:
https://github.com/ocornut/imgui

Font used

The font I used to replace the standard ImGui font is Blender Pro Book
Fonts made from Web Fonts is licensed by CC BY 4.0