8000 Book 1 Section 11.2 Formula Missing a Variable · Issue #1644 · RayTracing/raytracing.github.io · GitHub
[go: up one dir, main page]
More Web Proxy on the site http://driver.im/
Skip to content

Book 1 Section 11.2 Formula Missing a Variable #1644

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom
Closed
ReneeeZhang opened this issue Oct 5, 2024 · 3 comments
Closed

Book 1 Section 11.2 Formula Missing a Variable #1644

ReneeeZhang opened this issue Oct 5, 2024 · 3 comments
Assignees
@hollasch
Labels
book 1: One Weekend level: patch status: in PR
Milestone
v4.0.2

Comments

@ReneeeZhang
Copy link
ReneeeZhang commented Oct 5, 2024 •
edited
Loading

The highlighted formula in the following screenshot is missing a variable
Screenshot 2024-10-05 at 2 25 12 PM
$$ \mathbf{R}'\perp = \frac{\eta}{\eta'} \left( \mathbf{R} + \cos \theta \mathbf{n} \right)$$ is wrong.
It should be:
$$ \mathbf{R}'\perp = \frac{\eta}{\eta'} \left( \mathbf{R} + |\mathbf{R}|\cos \theta \mathbf{n} \right) $$
Looks like:
Screenshot 2024-10-05 at 2 34 25 PM
@hollasch hollasch self-assigned this Oct 5, 2024
@hollasch hollasch added this to the v4.0.2 milestone Oct 5, 2024
@hollasch
Copy link
Collaborator
hollasch commented Oct 5, 2024

Note that in our code, $\mathbf{R}$ is a unit vector.

hollasch added a commit that referenced this issue Oct 5, 2024
@hollasch
Fix equation for refracted rays of non-unit length
53c6e39 
Resolves #1644
@hollasch hollasch mentioned this issue Oct 5, 2024
Merged
@ReneeeZhang
Copy link
Author

Thank you. I do notice that in the code $\mathbf{R}$ is a unit vector, but in the book, it does not explicitly say this assumption, which was a bit confusing when I tried to reason about the formula myself.

@hollasch
Copy link
Collaborator
hollasch commented Oct 7, 2024

Yeah, I noticed the same thing while going through the equations to verify. Your suggestion is a good one.

hollasch added a commit that referenced this issue Nov 6, 2024
@hollasch
Fix equation for refracted rays of non-unit length
f1772b0 
Resolves #1644
@hollasch hollasch closed this as completed Nov 6, 2024
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Assignees

@hollasch hollasch

Labels
book 1: One Weekend level: patch status: in PR
Projects
None yet
Milestone
v4.0.2
Development

No branches or pull requests
2 participants
@hollasch @ReneeeZhang
0