Hi, I have a job interview with Naughty Dog scheduled next week for a tool programmer position and I have been warned at least 3 times by email that the interview is going to be VERY (upper case in the mail as well) technical with a strong focus on 3D maths. Even though I don't really have doubts about my skills in 3D programming, that's kind of scary (it is also my first technical interview, I just graduated) :/ Does anyone have experience with this kind of job interview (tool programmer or game engine developer positions)? Could you give me question samples to see what "very technical" means... Advice from someone who has already taken an interview for Naughty Dog would be awesome of course :) If I could get a good overview of the kind of questions I am gonna have to answer, I could brush up a bit this week end and get ready (and feel more confident :) Thanks a lot!

Technical interviews are a pretty common thing in the industry when applying for a job that is, well, technical.

Common questions will run the gamut from low-level stuff (bit manipulation), mid-level stuff (language specific questions), and highlevel (design patterns, software architecture.) You'll also often see logic problems.

That said, if it's supposedly 3D math heavy, expect questions like:
(easy) Describe the nature of an identity matrix and what it's used for.
(harder) Describe the process of finding the intersection of a ray and a plane.

It's important to be prepared, but don't psyche yourself out!! Interviews are not set up to make you fail -- they are set up to prove your knowledge base. If you know your stuff and stay calm and collected, you'll do fine.

Good luck!

Quote: Original post by shadowcomplex
It's important to be prepared, but don't psyche yourself out!! Interviews are not set up to make you fail

Sometimes individual questions are set up to make you fail. It is not uncommon in interviews to slip in a really, really hard question, while making it sound like the answer would be absolutely common knowledge. It is expected that you will not be able to answer it. The idea is to check how you will handle the situation.

Quote: Original post by shadowcomplex
(harder) Describe the process of finding the intersection of a ray and a plane.

That's a pretty basic question, if the topic is really focussed on 3D.

Also, it's not so important that you answer every single question correctly, as long as you work through your answers step-by-step and let the interviewer know your thought process. So talk your way through each step (if they're with you as you answer the questions) or write down everything you're thinking about as you work it out. After all, you can't possibly know everything there is to know, as long as you know how to find out, then that's an important step.

For example, if asked the "ray & plane intersection" question, you can either simply write down the formula (bad) or start with the equation of a plane and the equation for a line and work, step by step, from there (good).

P.S. Good luck!

Quote: Original post by Yann L

Quote: Original post by shadowcomplex
It's important to be prepared, but don't psyche yourself out!! Interviews are not set up to make you fail

Sometimes individual questions are set up to make you fail. It is not uncommon in interviews to slip in a really, really hard question, while making it sound like the answer would be absolutely common knowledge. It is expected that you will not be able to answer it. The idea is to check how you will handle the situation.

Right -- but that's not an intention to make a person fail. If the candidate knows their stuff they won't be tripped up by such questions -- unless they fail to remain collected, which was my main take away.

Quote: Original post by Yann L

Quote: Original post by shadowcomplex
(harder) Describe the process of finding the intersection of a ray and a plane.

That's a pretty basic question, if the topic is really focussed on 3D.

Sure, I didn't say it was hard -- but this type of question is frequently used in the beginning of such a test to instantly weed out candiates who do not meet the required knowledge. I couldn't think of a harder one off the top of my head that I *know* has been used in such an interview :(

Edit: And I'll second what Codeka said.

I wish you luck, nice one aim high, Naughty Dog are prolly are one of the top3 of development studio's technique wise.
Thus dont be disappointed if you dont make it

Make sure you cover matricies in some detail...they will probably ask you to write a rotation matrix on the board or something (and I can never remember those offhand...).

I can't actually think of a "hard" maths question they could give you. I suppose they could ask you something to do with finding if a point lies in a triangle...but even that isn't super hard...

Most technical interviews are done to discover the depths of your knowledge. Keep that in mind during the interview.

Cramming for it doesn't help. A simple review of the topics may help a little, but don't freak out about it.


They expect to see that you can do the basics, but they also want to see what else you know. Again, the purpose is generally to find the outer edge of your knowledge and take you outside your comfort zone.


The people who perform the interview know the topic well, and have been working with it in-depth for many years. They can and will ask you questions that you cannot answer. They may ask questions that they cannot answer themselves. Again, remember that they are trying to see the edge of your knowledge. If you don't know, they want to see how far you can reason.

Expect to be asked progressively harder questions. Eventually they will hit questions that you cannot answer. Don't lie about it, and don't guess without explaining that you are guessing. Instead state that you don't know and then do your best to explain how you would get the answer.

Once the interviewer finds where the depth of knowledge is, they will begin to question topics around it. Again, these will be hard because they are at the limit of your knowledge. They are just trying to figure out the limits of what you know and see how your reasoning skills work.


Don't stress about it.

Know that there are a lot of experienced people out there who have been laid off, so even if you do exceptionally well on the technical side you may still be turned down in favor of somebody with prior experience.

Thanks everyone for your answers. I have a better idea of the kind of questions I might have to answer. As you said I can't learn much in a week end, I can just refresh a bit and get ready. We'll see how that goes.

Thanks ;)

I'd be prepared for questions like:

"What's a quaternion?"
"Why are they used?"
"What's gimbal lock, how do you avoid it"

etc etc. If they never mention quaternions, you might find a way to mention them. I'd be pleased an entry-level graduate knew that kind of stuff.

On matrices:

"What's the transpose of a matrix, how do you calculate it?"
"How do you invert a 3x3 (or 4x4) matrix? Can every matrix be inverted?"

But more likely you'll be asked about dot products & cross products & triple products - what they mathematically and what they are useful for. And stuff like point distance from a line/plane/sphere... standard high-school stuff. Showing you understand the application of math is a good thing.