RTXOn is an open source C# solution for the generation of photorealistic images using raytracing.
It is the result of a team effort of Andrea Mastropasqua and Giacomo Riccardo Hvaring, two Master Degree Students in Physics at the time of the release of v1.0.0 of this project.
The project is loosely1 based on a University Lab Course we attended in the Summer Semester of 2022, which tricked us into learning new coding skills, with the promise of basically making VFX artists out of us by the end of the semester.
Obviously, we did not get any call from Pixar (yet), but we feel confident about saying we moved our VFX artist bar from 0 to some number striclty greater than 0, and learned some C# in the process, among other things.
If you are still reading, we've got a prize for you: a beautiful image rendered with RTXOn! Which you can find in the next section.
With RTXOn you can generate an image similar to this one:
using the following command:
$ ./render demo
The syntax is explained on how to use RTXOn further down.
The next section explains how to get RTXOn up and running on your machine.
What follows is a step-by-step guide to install RTXOn and its dependencies.
To clone the repository, write the command:
$ git clone https://github.com/grhvaring/RTXOn.git
The symbol $ at the beginning of the line indicates that the command is supposed to be fed to the command line.
The project uses external libraries, here's how to install them.
ImageSharp 2.1.0 (used for the conversion between HDR and LDR images) can be installed with the following command:
$ dotnet add package SixLabors.ImageSharp --version 2.1.0
CommandLineParser 2.8.0 (manages CL runtime options) can be installed with this command:
$ dotnet add package CommandLineParser --version 2.8.0
To build the project run the command:
$ dotnet build -c Release
The option -c (configuration) is usually set to Debug by default, switching to Release mode makes the execution of the program significantly faster.
To check that the program behaves as expected, you can run the unit tests using this command:
$ dotnet test
If you arrived here in one piece, congratulations ! You succesfully installed and tested RTXOn!
The next section explains how to use it.
The fastest way to use RTXOn is with the program render, a short Bash script which deals with all the nitty-gritty details of the image generation for you.
Before you run it though, you need to make render executable if it is not already, and you can do so with this command:
$ chmod +x render
Now, this is the command to render a 3D scene described in the file scene.txt:
./render scene
Remark: scene is not the complete name of the file, but the name without extension. In this case the complete name would be scene.txt, and is assumed to be in the sub-directory examples. So, if you create a new 3D scene file, make sure it satisfies these two requirements:
- It is encoded as a text file (ends with
.txt) - It is located in the sub-directory
examples
If you want to create your own 3D scene, take a look at the syntax of the already existing examples, and have fun !
This is the basic way of running RTXOn, for the more advanced way, keep reading.
If you like get your hands a little dirty, this section is for you: this is how to run RTXOn from the command line.
This command shows how to fine-tune the parameters of the image generation with RTXOn:
$ ./path-to-exe/RTXOn render --input-file examples/pyramid.txt --luminosity 50
path-to-exe indicates the position of the executable file (RTXOn) relative to the working directory. Usually it can be found in RTXOn/bin/Release/net6.0/, as depicted in this directory tree:
├── RTXOn
│ ├── bin
│ │ └── Release
│ │ └── net6.0
│ │ ├── RTXOn
│ │ ...
│ ├── obj
│ │ └── ...
│ ├── RTXOn.cs
│ └── RTXOn.csproj
│
├── RTXLib
│ ...
│
├── RTXLib.Tests
│ ...
render is an option passed to the main program, which tells it to render a 3D scene parsing a text file. What text file? pyramid.txt, located in examples.
The option luminosity overrides the average luminosity of the image, making the image brighter (darker) when the luminosity passed is smaller (bigger) than the original value calculated directly with the pixel values.
This is the basic syntax, for a more in-depth explanation of the process of image generation, take a look at the Professor's slides.
For a complete list of the options accepted by RTXOn, write the following command:
$ ./path-to-exe/RTXOn --help
That's it, have fun !
In case this project turns out to be useful to someone other than us, we'd be (first of all surprised, but also) very happy to know more about it !
If you have a suggestion that would make the project better, please fork the repo and create a pull request. You can also simply open an issue with the tag "enhancement".
Any contribution you make is greatly appreciated.
RTXOn is distributed under the Apache 2.0 License. See LICENSE.txt for more information.
Andrea Mastropasqua: andrea.mastropasqua@studenti.unimi.it
Giacomo Riccardo Hvaring: giacomoriccardo.hvaring@studenti.unimi.it
We thank SixLabors for releasing ImageSharp free of charge: it took care of the conversion to PNG for us !
We thank also all the contributors to CommandLineParser, for allowing us to integrate seamlessly command line options in our code.
And of course, we thank our parents for sponsoring us while we learned how to make CG balls for 6 months.