jdunlap

jdunlap

The Ray Tracer Challenge: Implementing Shading Breaks the First Shading Test on P. 95

I am working on Chapter 8 when we add shadows. When this is done, though (on p. 115), the original ShadeHit test no longer passes. This point is in shadow and will, therefore, break the tests once shading is implemented.

My solution was to add a flag to turn shading on and off. It defaults to on, but I turn it off before running this test so that it runs as originally intended. I then turn it back on for the final test that is added on p. 114.

For anyone who wants to just update the test, here is the value that I get:

Expected: {0.38066, 0.47583, 0.2855, 0 }
Actual: {0.08, 0.1, 0.06, 0 }

The Actual would just be the ambient color of the sphere.

The second test from p. 95 also fails. Those values are:

Expected: {0.90498, 0.90498, 0.90498, 0 }
Actual: {0.1, 0.1, 0.1, 0 }

Edit:

Shading also breaks the Render test on p. 104 and the second colorAt test on p. 96.

These tests need to be changed to test for the Ambient color or shading needs to be turned off to run them.

It would be nice if Jamis would create tests for all of these that are not in shade or would adjust these tests in the text since the design of the program changed.

First Post!

jamis

jamis

Author of Mazes for Programmers and 1 other title

Hello,

The tests as written should be passing; my own renderer passes all tests, through the end of the book. Admittedly, there could very well be an error in my own code that permits this, but other readers have also had these tests pass after the shadow chapter.

Is your code hosted anywhere that I can see it? I’d be happy to take a look.

  • Jamis

Where Next?

Popular Pragmatic Bookshelf topics Top

belgoros
Following the steps described in Chapter 6 of the book, I’m stuck with running the migration as described on page 84: bundle exec sequel...
New
brianokken
Many tasks_proj/tests directories exist in chapters 2, 3, 5 that have tests that use the custom markers smoke and get, which are not decl...
New
jamis
The following is cross-posted from the original Ray Tracer Challenge forum, from a post by garfieldnate. I’m cross-posting it so that the...
New
Mmm
Hi, build fails on: bracket-lib = “~0.8.1” when running on Mac Mini M1 Rust version 1.5.0: Compiling winit v0.22.2 error[E0308]: mi...
New
raul
Page 28: It implements io.ReaderAt on the store type. Sorry if it’s a dumb question but was the io.ReaderAt supposed to be io.ReadAt? ...
New
joepstender
The generated iex result below should list products instead of product for the metadata. (page 67) iex> product = %Product{} %Pento....
New
rmurray10127
Title: Intuitive Python: docker run… denied error (page 2) Attempted to run the docker command in both CLI and Powershell PS C:\Users\r...
New
New
brian-m-ops
#book-python-testing-with-pytest-second-edition Hi. Thanks for writing the book. I am just learning so this might just of been an issue ...
New
brunogirin
When I run the coverage example to report on missing lines, I get: pytest --cov=cards --report=term-missing ch7 ERROR: usage: pytest [op...
New

Other popular topics Top

Devtalk
Reading something? Working on something? Planning something? Changing jobs even!? If you’re up for sharing, please let us know what you’...
1050 21151 394
New
PragmaticBookshelf
Machine learning can be intimidating, with its reliance on math and algorithms that most programmers don't encounter in their regular wor...
New
PragmaticBookshelf
Learn from the award-winning programming series that inspired the Elixir language, and go on a step-by-step journey through the most impo...
New
AstonJ
If you are experiencing Rails console using 100% CPU on your dev machine, then updating your development and test gems might fix the issu...
New
rustkas
Intensively researching Erlang books and additional resources on it, I have found that the topic of using Regular Expressions is either c...
New
foxtrottwist
A few weeks ago I started using Warp a terminal written in rust. Though in it’s current state of development there are a few caveats (tab...
New
AstonJ
We’ve talked about his book briefly here but it is quickly becoming obsolete - so he’s decided to create a series of 7 podcasts, the firs...
New
PragmaticBookshelf
Build efficient applications that exploit the unique benefits of a pure functional language, learning from an engineer who uses Haskell t...
New
PragmaticBookshelf
Author Spotlight: Peter Ullrich @PJUllrich Data is at the core of every business, but it is useless if nobody can access and analyze ...
New
mindriot
Ok, well here are some thoughts and opinions on some of the ergonomic keyboards I have, I guess like mini review of each that I use enoug...
New

Sub Categories: