As we were recently hiring a new Graphics Programmer at work I had to identify what kind of technical knowledge and skills we would expect from a potential candidate. Although this definition will be somewhat specific to what we look for in a candidate, it might still be of interest to other coders trying to score a job in the industry as a Rendering Engineer.
This post might help you to identify areas to learn about in order to get you closer to your goal of becoming a Graphics Engineer, whether you just finished your degree or perhaps have been working in the games industry in a different role. Alternately, if you are a seasoned Rendering Programmer, then you know all of this stuff and I would love to hear your comments on the topic.
Learning about the strengths and weaknesses of the hardware that will execute your code should be important for any programmer, but it's an essential skill for a Graphics Engineer. Making your game look beautiful is important; getting all of the fancy effects to run at target frame rate is often the trickier part.
Of course, it would be unrealistic to expect you to know every little detail about the underlying hardware (especially if you are just starting out) but having a good high-level understanding of what is involved to make a 3D model appear on screen is a mandatory skill, in my opinion. A candidate should definitely know about the common GPU pipeline stages (e.g. vertex- and pixel-shader, rasterizer, etc.), what their functionality is and whether or not they are programmable, configurable or fixed.
Very often, there are many ways to implement a rendering effect, so it’s important to know which solution will work best on a given target device. Nothing is worse than having to tell the artists that they will have to modify all of the existing assets, because the GPU doesn’t support a necessary feature very well.
For example, the game that I am currently working on is targeting desktop computers as well as mobile devices, which is important because mobile GPUs have very different performance characteristics compared to their desktop counterparts (check out my 5 minute micro talk on this topic if you are interested). Our team took this difference into account when making decisions about the scene complexity and what kind of effects we would be able to draw.
A great way to learn more about GPUs is to read chapter 18 of Real-Time Rendering (Third Edition), because it contains an excellent overview of the Xbox 360, Playstation 3 and Mali (mobile) rendering architectures.
Extensive knowledge of trigonometry, linear algebra and even calculus is very important for a Graphics Programmer, since a lot of the day to day work involves dealing with math problems of varying complexities.
I certainly expect a candidate to know about the dot and cross products and why they are very useful in computer graphics. In addition to that, it is essential to have an intuitive understanding for the contents of a matrix, because debugging a rendering problem can make it necessary to manually ‘decompose’ a matrix in order to identify incorrect values. For example, not that long ago I had to fix a problem in our animation system and was able to identify the source of the problem purely by looking at the joint matrices.
In my opinion, a candidate should be able to analytically calculate the intersection between a ray and a plane. Also, given an incident vector and a normal, I would expect every Rendering Engineer to be able to easily derive the reflected vector.
There are plenty of resources available on the web. You can find some good resources here. The book "3D Math Primer for Graphics and Game Development" does a great job explaining a lot of the fundamentals like vectors, matrices and quaternions to name just a few topics. I would also strongly recommend attempting to solve some of these problems on a piece of paper instead of looking at a preexisting solution. It’s actually kind of fun, so you should definitely give it a try.
An ideal candidate will keep up to date with the latest developments in computer graphics especially since the field is constantly and rapidly advancing (just compare the visual fidelity of games made 10 years ago with what is possible today).
There are plenty of fascinating research papers (e.g. current SIGGRAPH publications), developer talks (e.g. GDC presentations) and technical blogs available on the internet, so it should be pretty easy to find something that interests you. Make sure to check out the blogs of fellow Rendering Engineers for some really inspiring articles!
Of course implementing an algorithm is the best way to learn about it, plus it gives you something to talk about in an interview. Writing a cool graphics demo also helps you to practice your skills and most of all it is a lot of fun.
If you want to maximize your chances of getting a job make sure to spend some time making your demo look pretty. You may have implemented the most efficient tessellation algorithm, but if people can't see what's going on they might not be as impressed as they should be. Creating visually pleasing images is a big part of the profession, so it's generally a good idea to show that you have this skill as well.
One of the responsibilities of a Graphics Programmer is to profile the game in order to identify and remove rendering related bottlenecks. If you are just starting out I wouldn’t necessarily expect you to have a lot of practical experience in this area, but you should definitely know the difference between being CPU and GPU bound.
An ideal candidate will have used at least one graphics analysis tool like PIX (part of the DirectX SDK), gDEBugger or Intel’s GPA. These applications are available for free allowing you to take a closer look at what’s going on inside of a GPU, isolate bugs (e.g. incorrect render-state when drawing geometry) and identify performance problems (e.g. texture stalls, slow shaders, etc.)
The job of a Graphics Programmer is pretty awesome since you’ll be directly involved with the visual appearance of a product. The look of a game is very often the first thing a player will know about it (e.g. trailers, screenshots) which has been very gratifying for me personally.
Truth be told, you won’t be able to write fancy shaders every day. You should be prepared to work on other tasks such as: data compression (e.g. textures, meshes, animations), mathematical and geometry problems (e.g. culling, intersection computations) as well as plenty of profiling and optimizations. Especially, the latter task can be very challenging since the GPU and the associated driver cannot be modified.
To sum up, becoming Rendering Engineer requires a lot of expert knowledge, and it is certainly not the easiest way to get a foot in the proverbial games industry door, but if you are passionate about computer graphics it might be the right place for you!
Note: This article was originally posted on #AltDevBlog in November 2013.