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
yulkin
your book suggests to use Image.toByteData() to convert image to bytes, however I get the following error: "the getter ‘toByteData’ isn’t...
New
lirux
Hi Jamis, I think there’s an issue with a test on chapter 6. I own the ebook, version P1.0 Feb. 2019. This test doesn’t pass for me: ...
New
HarryDeveloper
Hi @venkats, It has been mentioned in the description of ‘Supervisory Job’ title that 2 things as mentioned below result in the same eff...
New
AndyDavis3416
@noelrappin Running the webpack dev server, I receive the following warning: ERROR in tsconfig.json TS18003: No inputs were found in c...
New
jskubick
I think I might have found a problem involving SwitchCompat, thumbTint, and trackTint. As entered, the SwitchCompat changes color to hol...
New
jskubick
I’m under the impression that when the reader gets to page 136 (“View Data with the Database Inspector”), the code SHOULD be able to buil...
New
akraut
The markup used to display the uploaded image results in a Phoenix.LiveView.HTMLTokenizer.ParseError error. lib/pento_web/live/product_l...
New
creminology
Skimming ahead, much of the following is explained in Chapter 3, but new readers (like me!) will hit a roadblock in Chapter 2 with their ...
New
SlowburnAZ
Getting an error when installing the dependencies at the start of this chapter: could not compile dependency :exla, "mix compile" failed...
New

Other popular topics Top

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
Brace yourself for a fun challenge: build a photorealistic 3D renderer from scratch! In just a couple of weeks, build a ray tracer that r...
New
siddhant3030
I’m thinking of buying a monitor that I can rotate to use as a vertical monitor? Also, I want to know if someone is using it for program...
New
PragmaticBookshelf
Design and develop sophisticated 2D games that are as much fun to make as they are to play. From particle effects and pathfinding to soci...
New
PragmaticBookshelf
Rust is an exciting new programming language combining the power of C with memory safety, fearless concurrency, and productivity boosters...
New
PragmaticBookshelf
Author Spotlight Mike Riley @mriley This month, we turn the spotlight on Mike Riley, author of Portable Python Projects. Mike’s book ...
New
First poster: bot
zig/http.zig at 7cf2cbb33ef34c1d211135f56d30fe23b6cacd42 · ziglang/zig. General-purpose programming language and toolchain for maintaini...
New
CommunityNews
A Brief Review of the Minisforum V3 AMD Tablet. Update: I have created an awesome-minisforum-v3 GitHub repository to list information fo...
New
AstonJ
Curious what kind of results others are getting, I think actually prefer the 7B model to the 32B model, not only is it faster but the qua...
New
PragmaticBookshelf
A concise guide to MySQL 9 database administration, covering fundamental concepts, techniques, and best practices. Neil Smyth MySQL...
New

Sub Categories: