CGRA350: Real-time Rendering

Group Project: Real-time Renderers

This project is a 3D terrain simulation that features the ability for the user to move around the scene and edit the terrain mesh in real-time. Some interesting aspects of this project include:

• Terrain mesh generation using Perlin Noise with varying L.O.D.
• Procedurally generated trees that flow with the terrain as it is edited.
• Procedurally generated clouds using the Marching Cubes algorithm and Perlin Noise.
• Mesh simplification with varying voxel resolutions.
• Ability to edit the terrain mesh by raising or excavating certain areas.
• The terrain displays different textures depending on the height of the mesh at any given point.
• Interactive flying camera that lets the user move around the scene.

Team Members

• Adam Goodyear
• Marshall Scott
• Shekinah Pratap
• Tessa Power
• Timothy Green

Project Structure

work:
├───ext           # External libraries, included for simplicity 
├───res           # Asset/Texture files & a self-contained project for shaders
│   ├───assets
│   ├───shaders
│   └───textures
└───src
    ├───cgra      # CGRA350 Framework source code   
    ├───clouds    # Cloud model source code
    ├───mesh      # Code related to editing or simplifying a mesh
    ├───terrain   # Terrain model source code
    ├───trees     # Procedurally generated trees source code
    └───utils     # Utility classes used throughout the project

Prerequisites

• OpenGL v3.3
• CMake
• C++11 compiler

The recommended way to build this project is using CMake, so the best structure for the project files is to clone this project into a dedicated directory with the name work.

mkdir cgra350-group-project
cd cgra350-group-project
git clone https://github.com/tessapower/cgra350-group-project.git work

Alternatively, download the source code for the project, rename the root directory to work, and then place it into a dedicated directory for this project. In this same project directory, create a directory called build. The folder structure should now look like this:

cgra350-group-project:
├───build
└───work

How to Build

Linux

Command Line

The simpliest way to set up a basic project is to run the shell script f5.sh which runs the cmake, make and run commands for you:

./f5.sh

Alternativiely you can run the commands manually:

cd build
cmake ../work
make
cd ..

If the project builds without errors the executable should be located in the build/bin/ directory and can be run with:

./build/bin/base [args...]

Eclipse

Setting up for Eclipse is a little more complicated. Navigate to the build folder and run cmake for Eclipse:

cd build
cmake  -G "Eclipse  CDT4 - Unix  Makefiles" ../work

Start Eclipse and go to File > Import > Existing Projects into Workspace, browse to and select the build/ directory as the project. Make sure the box Copy Projects into Workspace is unchecked. Once you've imported the project, and are unable run it, do the following:

• Go to Run > Run Configurations.
• On the left side, select C/C++ Application.
• In the Main tab, make sure your C/C++ Application field contains ./bin/base and that Enable auto build is checked.
• Right click on the project and then select, Run As > C/C++ Application.

This should setup the default way to start the program, so you can simply run the project any time after that.

Windows

Visual Studio

This project requires at least Visual Studio 2017. You can get the latest, Visual Studio Community 2017, for free from Microsoft.

Product	XX
Visual Studio 2017	15

Change to the build directory and run the cmake command for Visual Studio with the appropriate version number (XX):

cd build
cmake -G "Visual Studio XX" ..\work

Or if you are building for 64-bit systems:

cmake -G "Visual Studio XX Win64" ..\work

After opening the solution (.sln) you will need to set some additional variables before running.

• Solution Explorer > base > [right click] > Set as StartUp Project
• Solution Explorer > base > [right click] > Properties > Configuration Properties > Debugging
• Select All Configurations from the configuration drop-down.
• Set Working Directory to $(SolutionDir)../work.

OSX

XCode

Xcode is an IDE that offers a little more than simple text editing. The setup again is very similar to Eclipse.

cd build
cmake -G "Xcode" ../work
cd ..

Once you're setup, you can build your project with Xcode, but have to execute your program with the terminal (making sure you are in the root directory):

./build/bin/base [args..]

How to Control

Simple Controls

• W for Zoom In, or Forward

• S for Zoom Out or Backwards

• A for Pan Left

• D for Pan Right

• Middle Mouse Click+Hold to rotate camera

ImGUI Controls

Voxel Settings

• Voxel Size
  • changes the amount of points sampled of the original mesh
• IsoLevel
  • how far away from the mesh a voxel point must be for it to be considered "solid"
• Smooth Normals
  • Toggles Smoothed Normals on/off
• Debugging (Menu)
  • Allows for visualisation of different steps in the simplification process of the Bunny
• Cloud Threshold
  • The threshold the noise value needs to pass to become a solid cloud.
• Cloud Fade out
  • the distance from the edge of the voxel grid that the cloud starts to fade out on the Y axis to prevent hard edges

Mesh Editing and Terrain

• Radius
  • Changes Radius of terrain manipulation
• Strength
  • Changes Strength of terrain manipulation
• Grass/Mud Height
  • Changes at what height the Grass/Mud Textures will appear
• Mud/Rocks Height
  • Changes at what height the Mud/Rocks Textures will appear
• Heighmap Scale
  • Changes intensity of heightmap
• Normal Map (Toggle)
  • Toggles on or off the normal map
• Raise/Excavate (Toggles)
  • Switches Mode to either Raise or Excavate Terrain
• Deform
  • Raises or Excavates the currently selected terrain
• Octaves
  • Number of times the noise values are iterated over
• Lacunarity
  • Affects the frequency of the noise
• Persistence
  • Affects the amplitude of the noise
• Height
  • Scales the height of the heightmap
• Repeats
  • Determines how many "tiles" the heightmap can repeat for
• Seed
  • Allows the permutation map to become seeded for deterministic randomness
• Perlin/Flat (Toggles)
  • Switches Mode to generate either flat or Perlin based Terrain
• Recreate Terrain
  • Regenerates Terrain with new values

Tree Settings

• Spooky Mode
  • Turns spooky mode on or off (Disables or Enables showing of foliage)
• New Tree
  • Generates a new base tree
• Print Tree
  • Prints a list of every branch in the tree and the information about that branch