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Examples

All of the examples here would qualify for full completion or higher for different combinations of creativity and good composition, and various implemented technical features.

If you want a safe and straightforward path to full completion, we suggest picking two technical features mentioned on this page and implementing them. If your group implements two technical features reasonably well, even in a scene with pretty boring composition, we will at least give you completion credit.

Some technical features could be worth more than others, and the value may be greater for especially impressive execution of a technical feature. But you can consider implementing two technical features a pretty safe bet.

Strategic feature combinations

Think about what features to prioritize and how certain feature might complement each other. For example, some features might substantially increase computation time, which could be offset by choosing to implement an acceleration structure as another one of your features.

You can also use the obj loader included in the code to load simple models. The most straightforward way to create such models would be to use Blender. Blender is free and open source, and there are lots of tutorials online that show how to use it. With an un-accelerated ray tracer written in Python you won't be able to render very complex models, but you can certainly do a lot with low polygon content.

Using tools like Blender

See Exporting from Blender for tips on how to use Blender, an open source cross-platform 3D modeling tool, to help you create and export models. If you use 3D asset files in your scene, be sure to identify what parts of the scene were loaded from files, and how you obtained or created those files! As you will see in several of the examples below, you can do a lot of cool stuff without the aid of 3D modeling software, but tools like Blender are an option.

Create a cool scene:​

You don't necessarily have to implement a fancy technical feature to do well in this assignment. Rather, making particularly good use of the basics can demonstrate strong understanding of the fundamentals, which deserves its own reward. For example, both of the submissions below amount to very artistic/clever use of spheres to render an interesting scenes, with good lighting and composition.

Composition as a Selling Point

If you plan to focus on creating a compelling scene like this, it will take some trial and error. A lot of care went into placing spheres, camera, and lights in these scenes. Try to set up an efficient pipeline for exploring these options early on, so you can quickly iterate and find parameters that look best.

Hungry Hungry Caterpillar, by Ally Younkman and Oluwatise Alatise:​

Kirby in Space, by Yingshi Zhu and Mandy Kwok​

Potential Features To Implement

We will also certainly give credit for implementing cool technical features. A reasonably composed scene with a well-executed technical feature is probably the safest way to get full completion credit.

Be accurate in your reports!

Your technical feature needs to work (at least excluding very edge cases). Do not claim that you have implemented something that you have not; we will check suspicious claims, you may be penalized if they seem very inflated, and particularly egregious (e.g., deliberate-looking) false claims may be treated as academic dishonesty.

Some ideas to consider include:

  • Extended Obj Loader: The current obj loader provided in A4 will only work with obj files that have only 1 mesh. However, it should not be hard to extend it into an obj loader that can handle multiple meshes. The read_obj and read_obj_triangles functions in A4, along with cube.py scene example should be helpful for you to learn from, and experiment with. You can also create some obj files with multiple meshes in Blender, and analize those files to implement your own loader. With such Extended Obj Loader, you can easily create a complex composition in Blender, adjust your camera as you like (remember to note down those parameters from Blender), export the scene to an obj file, and render with your own handcrafted ray tracer!
  • Additional geometric primitives: you can add new primitives and implement their ray intersection calls and use them to create new shapes. Note that a primitive that is simply an array of existing primitives does not count as a new primitive (e.g., the cube is just a collection of simple triangles). A simple plane will not be treated as an extra feature, either.
  • Constructive solid geometry (CSG): implement boolean operations on existing primitives. E.g., the intersection of two spheres can create a pretty cool flying saucer shape (see UFOs below...).
  • Additional shading modes or phenomena: E.g., refraction, or more general BRDFs, E.g.,
    • Fresnel reflection
    • Refraction, caustics, lensing
    • Scattering
  • Surface Texture Mapping: Various types of texture mapping including
    • Diffuse texture mapping
    • Displacement mapping
    • Normal Mapping
    • Bump Mapping
  • Acceleration structures: You could implement code to make ray tracing faster. We haven't discussed this much in class, but I have uploaded a bonus video from Steve on the topic to Canvas, and if you are interested it is certainly google-able. Make sure you describe this type of feature clearly in your submission, as it won't necessarily be visible in an image. Also, this feature works best if you use it to ray trace a higher resolution, more anti-aliased, and/or more complex scene with more complicated effects. Report the speed gains you get on your machine in your report. Also note that we can and do check to see that you actually implemented what you say you did here.

UFO Scenes​

These images show a UFO created using constructive solid geometry. The saucer of the UFO is the intersection of two spheres. The top and bottom of the ufo have additional spheres as well.

In our first UFO scene we render the UFO above some paraboloid grass hills:

In our second UFO scene we render the UFO above the desert ground (UFOs like the desert). Here, the desert is rendered with a normal map and a diffuse texture map. I would consider the composition reasonably good for both of these images.

Submissions from Previous Years

CSG on the moon / desert... by Yiheng Dong and Mingzhao Liu​

This submission has nicely implemented CSG, as well as normal mapping and pretty good composition.

CSG and Ellipsoids by Ruyu Yan and Becky Hu​

This submission has nicely implemented CSG, as well as ellipsoids, some new material, and great composition.

Solar Donut Dolly Zoom by Dubem Ogwulumba and William Ma​

The top submission from 2021

Some 2022 Examples

Prithwish Dan & Simon Kapen​

Very impressive use of constructive solid geometry. The entire scene is made from CSG by combining various basic shapes.

Sissel Sun & Claire Zhou​

Nicholas Broussard & Orion Tian​

Jack Otto and Sean Brynjolfsson​

This one was rendered using fractals, which lend themselves well to accelerated ray tracing of very complex geometry.