Dyalog APL code for the ray tracer described in The Ray Tracer Challenge A Test-Driven Guide to Your First 3D Renderer by James Buck from The Pragmatic Programmers https://pragprog.com/book/jbtracer/the-ray-tracer-challenge
Sincere thanks to Dyalog Ltd. for making available a non-commercial, personal license of their APL interpreter and environment. To learn more about APL visit tryapl.org for an online interpreter with demos, tutorials, and more.
The Ray Tracer code was developed within a set of three Jupyter notebooks, one for the code itself, another for the tests, and a third for the demo scenes at the end of each chapter. Tests started in the code notebook and, once all were passing, were then transferred to the test notebook. The Jupyter Lab application facilitated the management of these notebooks.
- Chapter 1. Tuples, Points, and Vectors
- Chapter 2. Drawing on a Canvas
- Chapter 3. Matrices
- Chapter 4. Matrix Transforms
- Chapter 5. Ray-Sphere Intersections
- Chapter 6. Light and Shading
- Chapter 7. Making a Scene
- Chapter 8. Shadows
- Chapter 9. Planes
- Chapter 10. Patterns
- Chapter 11. Reflection and Refraction
- Chapter 12. Cubes
- Chapter 13. Cylinders
- Chapter 14. Groups (heavily modified!)
- Chapter 15. Triangles (partial)
- Chapter 16. Constructive Solid Geometry
- Add additional Patterns
- Full Wavefront OBJ file support
- Scene description language support (YAML?)
- Object-oriented APL implementation (stretch goal)
19-March-2019. Put ray tracer code in its own namespace (RayTracer). The Test and Demo notebooks have not yet been updated to take this change into account.
20-March-2019. Fixed issue with reflection overriding transparency for objects having both attributes.
23-March-2019. Updated the Demo notebook so that the individual scenes would work with the new arrangement of ray tracer code in a separate namespace. Updated the code so that the inverse of each object's transform matrix is precomputed and stored in the object during scene construction. This results in a speed improvement of about ten percent.
2-April-2019. Fixed issue with incorrect reflection calculation. Reflection was only working with Plane objects due to an incorrect calculation of the reflectv vector in prepare_computations.
6-May-2019. Added support for multiple light sources. Modified the definition of a point light source so that it can have a radius from which rays are emitted. Rays are emitted in a normal (Gaussian) scatter about the light center point.
16-May-2019. Added parallel rendering using isolates. Result is roughly a 2.5 times speedup on a 4 CPU machine. See new rendering command llrender. Be sure to "")copy isolate" before running. Use the function "w llrender c" where "w" is a world structure and "c" is a camera.
31-May-2019. Added Radial Gradient and Blend patterns. Patterns can now be nested, allowing patterns in place of simple color in the pattern specification.
4-June-2019. Added Perlin Noise function and used it to create two new patterns, Perlin and Perlin Gradient.
13-June-2019. Added a function to render a scene to a graphics window. Use the command "w wrender c" where "w" is a world structure and "c" is a camera. Use the "Quit" button to terminate or exit.
15-June-2019. First release of a more complete how-to manual called "Creating a Scene"
31-October-2019. Inclusion of .aplf text files containing individual APL functions using the ]LINK command included as part of the new Dyalog APL 17.1 release. The files can be found in the RayTracer directory.