Tag Archives: Jak and Daxter

So you want to be a video game programmer? – part 2 – Specs

…CONTINUED FROM PART 1.

There are a couple of broad categories of programmers working on video game teams. If programmer is your player class, then the following types are your spec. Programmers are all warlocks and mages so instead of “demonology” or “frost” you can choose from below. (NOTE: if you don’t get this joke, you don’t play enough video games) This is the real world however, and many programmers dual (or even triple) spec — i.e. they handle multiple specialties.

1. Gameplay programmer. Programs enemies, characters, interfaces, gameplay setups etc. Probably also does things like AI and collision detection. These programmers are sometimes a little less hardcore technical than some of the other types, but this is the sub-field where the most “art” and experience are often required. Learning how to make a character’s control feel good is not something you can read about in Knuth. It takes the right kind of creative personality and a lot of trial and error. In a lot of ways, this is the heart and soul of game programming, the spec that truly differentiates us from the more engineering programming disciplines.

2. Tools programmer. Works on the extensive tools pipeline that all games have. This is the only branch of game programming where you don’t absolutely have to know and breathe video games inside and out, and it’s a little closer to mainstream applications programming. That being said, life at most video game companies is so intense, you better love them. Tools programmers tend to be very good at practical algorithms, data processing, etc. For some reason, perhaps because it’s more “behind the scenes” this spec is often viewed as less glamourous and there are fewer programmers who want to go into it.

3. Sound programmer. A very specific niche. Here you have to not only know how to program well, but you have to care about the esoteric field of sound. You need the kind of ear that can tell if there is a one sample glitch in some audio loop, and you need to care if the 3D audio spatialization is off or the sound field isn’t balanced. This is often a fairly low level area as audio programming is often done on DSPs.

4. Collision programmer. This is a really specific spec, and often overlaps with Graphics because it involves totally intense amounts of math. You better have taken BC calculus in tenth grade and thought “diffy-q” was the coolest class ever if you want to go into this.

5. Network programmer. In this era of multiplayer and networked gaming there’s a lot of networking going on. And programming across the internet is a bit of a specialty of it’s own. In general, video game programming takes any sub-field of programming to it’s most extreme, pushing the bleeding limits, and networking is no exception. Games often use hairy UDP and peer-to-peer custom protocols where every last bit counts and the slightest packet loss can make for a terrible game experience. If this is your thing, you better know every last nuance of the TCP/IP protocol and be able to read raw packet dumps.

6. Graphics programmer. Some guys really dig graphics and are phenomenal at math. If you don’t shit 4×4 matrices and talk to your mom about shaders, don’t bother. This sub-specialty is often very low-level as graphics programming often involves a lot of optimization. It may involve coming up with a cool new way of environment mapping, some method of packing more vertices through the pipeline, or better smoothing of the quaternions in the character joints (HINT: involves imaginary math — and if you don’t know that that means the square-root of -1 then this sub-field might not be for you).

7. Engine programmer. For some reason, most wannabe video game programmers hold this up as their goal. They want to have created the latest and greatest video game engine with the coolest graphics. Superstars like Tim Sweeney,John Carmack, and even myself are usually seen as falling in this category. The truth is that superstars do all kinds of programming, and are often distinguished by the fact that we are willing and able to handle any sub-type and tie it all together (see lead below). In my mind engine programmers are jacks-of-all-trades, good at building systems and gluing them together. The top guys often blend with Graphics and Lead below. There’s also tons of stuff like compression (nothing uses compression like games, we’d often have 8-10 different custom compressors in a game), multi-threading, load systems (you think seamless loading like in Jak & Daxter is easy?), process management, etc.

8. Lead programmer. People also dream of being the lead. All the great programmers are/were. This is the hardest spec, and no one ever starts out in it. You need to be able to do any of the other specs, or at least judge what approach is best. You need to be able to roll up your sleeves and dive in and fix crap anywhere in the program. You need to live without sleep (4 hours a night every day for years baby!). You need to be able to squint at the screen and guess where the bug is in others people’s code. You need to know how to glue systems together. You need to be able and willing to trim memory footprints and optimize (no one else wants to do it). In fact, you have to know the entire program, even if it is 5-10 million lines of code, and you have to do all the crap that no one else wants to do. Plus, you often have to manage a bevy of other personalities and waste lots and lots of time in meetings. Still want the glory? Being lead is all about responsibility!

CONTINUED with Part 3: Getting Started

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Parts of this series are: [Why, The Specs, Getting Started, School, Method]

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Crash Bandicoot – Teaching an Old Dog New Bits – part 3

This is the twelfth of a now lengthy series of posts on the making of Crash Bandicoot. Click here for the PREVIOUS or for the BEGINNING of the whole mess.

The text below is another journal article I wrote on making Crash in 1999. This is the third part, the FIRST can be found here.

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The Crash Bandicoot Trilogy: A Practical Example

The three Crash Bandicoot games represent a clear example of the process of technology and gameplay refinement on a single platform.  Crash Bandicoot was Naughty Dog’s first game on the Sony Playstation game console, and its first fully 3D game.  With Crash Bandicoot 2: Cortex Strikes Back and Crash Bandicoot: Warped, we were able to improve the technology, and offer a slicker more detailed game experience in successively less development time.  With the exception of added support for the Analog Joystick, Dual Shock Controller, and Sony Pocketstation the hardware platforms for the three titles are identical.

Timely and reasonably orderly development of a video game title is about risk management.  Given that you have a certain amount of time to develop the title, you can only allow for a certain quantity of gameplay and technology risks during the course of development.  One of the principle ways in which successive games improve is by the reuse of these risks.  Most solutions which worked for the earlier game will work again, if desired, in the new game.  In addition, many techniques can be gleaned from other games on the same machine that have been released during the elapsed time.

In the case of sequels such as the later Crash games there is even more reduction of risk.  Most gameplay risks, as well as significant art, code, and sound can be reused.  This allows the development team to concentrate on adding new features, while at the same time retaining all the good things about the old game.  The result is that sequels are empirically better games.

Crash Bandicoot   –   how do we do character action in 3D?

Development: September 1994 – September 1996

Staff: 9 people: 3 programmers, 4 artists, 1 designer, 1 support

Premise: Do for the ultra popular platform action game genre what Virtua Fighter had done for fighting games: bring it into 3D.  Design a very likeable broad market character and place him in a fun, and fast paced action game.  Attempt to occupy the “official character” niche on the then empty Playstation market.  Remember, that by the fall of 1994 no one had yet produced an effective 3D platform action game.

Gameplay risk: how do you design and control an action character in 3D such that the feel is as natural and intuitive as in 2D?

When we first asked ourselves, “what do you get if you put Sonic the Hedgehog (or any other character action game for that matter) in 3D,” the answer that came to mind was: “a game where you always see Sonic’s Ass.”  The entire question of how to make a platform game in 3D was the single largest design risk on the project.  We spent 9 months struggling with this before there was a single fun level.  However, by the time this happened we had formulated many of the basic concepts of the Crash gameplay.

We were trying to preserve all of the good elements of classic platform games.  To us this meant really good control, faced paced action, and progressively ramping challenges.  In order to maintain a very solid control feel we opted to keep the camera relatively stable, and to orient the control axis with respect to the camera.  Basically this means that Crash moves into the screen when you push up on the joypad.  This may seem obvious, but it was not at the time, and there are many 3D games which use different (and usually inferior) schemes.

Technical risk: how do you get the Playstation CPU and GPU to draw complex organic scenes with a high degree of texture and color complexity, good sorting, and a solid high resolution look?

It took quite a while, a few clever tricks, and not a little bit of assembly writing and rewriting of the polygon engines.  One of our major realizations was that on a CD based game system with a 33mhz processor, it is favorable to pre-compute many kinds of data in non real-time on the faster workstations, and then use a lean fast game engine to deliver high performance.

Technical risk: how do the artists build and maintain roughly 1 million polygon levels with per poly and per vertex texture and color assignment?

The challenge of constructing large detailed levels turned out to be one of the biggest challenges of the whole project.  We didn’t want to duplicate the huge amount of work that has gone into making the commercial 3D modeling packages, so we chose to integrate with one of them.  We tried Softimage at first, but a number of factors caused us to switch to AliasPower Animator.  When we began the project it was not possible to load and view a one million polygon level on a 200mhz R4400 Indigo II Extreme.  We spent several months creating a system and tools by which smaller chunks of the level could be hierarchically assembled into a larger whole.

In addition, the commercial packages were not aware that anyone would desire per polygon and per vertex control over texture, color, and shading information.  They used a projective texture model preferred by the film and effects industry.  In order to maximize the limited amount of memory on the Playstation we knew we would need to have very detailed control.  So we created a suite of custom tools to aid in the assignment of surface details to Power Animator models.  Many of these features have since folded into the commercial programs, but at the time we were among the first to make use of this style of model construction.

Technical risk: how do you get a 200mhz R4400 Indigo II to process a 1 million polygon level?

For the first time in our experience, it became necessary to put some real thought into the design of the offline data processing pipeline.  When we first wrote the level processing tool it took 20 hours to run a small test case.  A crisis ensued and we were forced to both seriously optimize the performance of the tool and multithread it so that the process could be distributed across a number of workstations.

Conventional wisdom says that game tools are child’s play.  Historically speaking, this is a fair judgment — 2D games almost never involve either sophisticated preprocessing or huge data sets.  But now that game consoles house dedicated polygon rendering hardware, the kid gloves are off.

In Crash Bandicoot players explore levels composed of over a million polygons.  Quick and dirty techniques that work for smaller data sets (e.g., repeated linear searches instead of binary searches or hash table lookups) no longer suffice.  Data structures now matter — choosing one that doesn’t scale well as the problem size increases leads to level processing tasks that take hours instead of seconds.

The problems have gotten correspondingly harder, too.  Building an optimal BSP tree, finding ideal polygon strips, determining the best way to pack data into fixed-size pages for CD streaming — these are all tough problems by any metric, academic or practical.

To make matters worse, game tools undergo constant revision as the run-time engine evolves towards the bleeding edge of available technology.  Unlike many jobs, where programmers write functional units according to a rigid a priori specification, games begin with a vague “what-if” technical spec — one that inevitably changes as the team learns how to best exploit the target machine for graphics and gameplay.

The Crash tools became a test bed for developing techniques for large database management, parallel execution, data flexibility, and complicated compression and bin packing techniques.

Art / Technical risk: how do you make low poly 3D characters that don’t look like the “Money for Nothing” video?

From the beginning, the Crash art design was very cartoon in style.  We wanted to back up our organic stylized environments with highly animated cartoon characters that looked 3D, but not polygonal.  By using a single skinned polygonal mesh model similar to the kind used in cutting edge special effects shots (except with a lot less polygons),  we were able to create a three dimensional cartoon look.  Unlike the traditional “chain of sausages” style of modeling, the single skin allows interesting “squash and stretch” style animation like that in traditional cartoons.

By very careful hand modeling, and judicious use of both textured and shaded polygons, we were able to keep these models within reasonable polygon limits.  In addition, it was our belief that because Crash was the most important thing in the game, he deserved a substantial percentage of the game’s resources.  Our animation system allows Crash to have unique facial expressions for each animation, helping to convey his personality.

Technical risk: how do you fit a million polygons, tons of textures, thousands of frames of animation, and lots of creatures into a couple megs of memory?

Perhaps the single largest technical risk of the entire project was the memory issue.  Although there was a plan from the beginning, this issue was not tackled until February of 1996.  At this point we had over 20 levels in various stages of completion, all of which consumed between 2 and 5 megabytes of memory.  They had to fit into about 1.2 megabytes of active area.

At the beginning of the project we had decided that the CD was the system resource least likely to be fully utilized, and that system memory (of various sorts) was going to be one of the greatest constraints.  We planned to trade CD bandwidth and space for increased level size.

The Crash series employs an extremely complicated virtual memory scheme which dynamically swaps into memory any kind of game component: geometry, animation, texture, code, sound, collision data, camera data, etc.  A workstation based tool called NPT implements an expert system for laying out the disk.  This tool belongs to the class of formal Artificially Intelligence programs.  Its job is to figure out how the 500 to 1000 resources that make up a Crash level can be arranged so as to never have more than 1.2 megabytes needed in memory at any time.  A multithreaded virtual memory implementation follows the instructions produced by the tool in order to achieve this effect at run time.  Together they manage and optimize the essential resources of main, texture, and sound RAM based on a larger CD based database.

Technical/Design risk: what to do with the camera?

With the 32 bit generation of games, cameras have become a first class character in any 3D game.  However, we did not realize this until considerably into the project.  Crash represents our first tentative stab at how to do an aesthetic job of controlling the camera without detracting from gameplay.  Although it was rewritten perhaps five times during the project, the final camera is fairly straightforward from the perspective of the user.  None of the crop of 1995 and 1996 3D action games played very well until Mario 64 and Crash.  These two games, while very different, were released within two months of each other, and we were essentially finished with Crash when we first saw Mario.  Earlier games had featured some inducement of motion sickness and a difficulty for the players in quickly judging the layout of the scene.  In order to enhance the tight, high impact feel of Crash’s gameplay, we were fairly conservative with the camera.  As a result Crash retains the quick action feel of the traditional 2D platform game more faithfully than other 3D games.

Technical risk: how do you make a character collide in a reasonable fashion with an arbitrary 3D world… at 30 frames a second?

Another of the games more difficult challenges was in the area of collision detection.  From the beginning we believed this would be difficult, and indeed it was.  For action games, collision is a critical part of the overall feel of the game.  Since the player is looking down on a character in the 3rd person he is intimately aware when the collision does not react reasonably.

Crash can often be within a meter or two of several hundred polygons.  This means that the game has to store and process a great deal of data in order to calculate the collision reactions.  We had to comb through the computer science literature for innovative new ways of compressing and storing this database.  One of our programmers spent better than six months on the collision detection part of the game, writing and rewriting the entire system half a dozen times.  Finally, with some very clever ideas, and a lot of hacks, it ended up working reasonably well.

Technical risk: how do you program, coordinate, and maintain the code for several hundred different game objects?

Object control code, which the gaming world euphemistically calls AI, typically runs only a couple of times per frame. For this kind of code, speed of implementation, flexibility, and ease of later modification are the most important requirements.  This is because games are all about gameplay, and good gameplay only comes from constant experimentation with and extensive reworking of the code that controls the game’s objects.

The constructs and abstractions of standard programming languages are not well suited to object authoring, particularly when it comes to flow of control and state.  For Crash Bandicoot we implemented GOOL (Game Oriented Object LISP), a compiled language designed specifically for object control code that addresses the limitations of traditional languages.

Having a custom language whose primitives and constructs both lend them selves to the general task (object programming), and are customizable to the specific task (a particular object) makes it much easier to write clean descriptive code very quickly.  GOOL makes it possible to prototype a new creature or object in as little as 10 minutes.  New things can be tried and quickly elaborated or discarded. If the object doesn’t work out it can be pulled from the game in seconds without leaving any hard to find and wasteful traces behind in the source.  In addition, since GOOL is a compiled language produced by an advanced register coloring compiler with reductions, flow analysis, and simple continuations it is at least as efficient as C, more so in many cases because of its more specific knowledge of the task at hand.  The use of a custom compiler allowed us to escape many of the classic problems of C.

Crash Bandicoot 2: Cortex Strikes Back  –   Bigger and Badder!

Development: October 1996 – November 1997

Staff: 14 people: 4 programmers, 6 artists, 1 designer, 3 support

Premise: Make a sequel to the best selling Crash Bandicoot that delivered on all the good elements of the first game, as well as correcting many of our mistakes.  Increasing the technical muscle of the game, and improving upon the gameplay, all without looking “been there done that…” in one year.

For Crash 2 we rewrote approximately 80% of the game engine and tool code.  We did so module by module in order to allow continuous development of game levels.  Having learned during Crash 1 about what we really needed out of each module we proceeded to rewrite them rapidly so that they offered greater speed and flexibility.

Technical risk: A fancy new tools pipeline designed to deal with a constantly changing game engine?

The workstation based tools pipeline was a crucial part of Crash 1.  However, at the time of its original conception, it was not clear that this was going to be the case.  The new Crash 2 tools pipe was built around a consistent database structure designed to allow the evolution of level databases, automatic I/O for complex data types, data browsing and searching, and a number of other features.  The pipe was modularized and various built-in restrictions were removed.  The new pipe was able to support the easy addition of arbitrary new types of data and information to various objects without outdating old information.

We could never have designed such a clean tool program that would be able to handle the changes and additions of Crash 2 and Warped at the beginning of the first game.  Being aware of what was needed at the start of the rewrite allowed us to design a general infrastructure that could support all of the features we had in mind.  This infrastructure was then flexible enough to support the new features added to both sequels.

Technical/process risk: The process of making and refining levels took too long during the first game.  Can we improve it?

The most significant bottleneck in making Crash 1 was the overall time it took to build and tune a level.  So for Crash 2 we took a serious look at this process and attempted to improve it.

For the artists, the task of surfacing polygons (applying texture and color) was very time consuming.  Therefore, we made improvements to our surfacing tools.

For both the artists and designers, the specification of different resources in the level was exceedingly tedious.  So we added a number of modules to the tools pipeline designed to automatically balance and distribute many of these resources, as well as to auto calculate the active ranges of objects and other resources that had to be controlled manually in the first game.  In addition, we moved the specification of camera, camera info, game objects, and game object info into new text based configuration files.  These files allowed programmers and designers to edit and add information more easily, and it also allowed the programmers to add new kinds of information quickly and easily.

The result of this process was not really that levels took any less time to make, but that the complexity allowed was several times that of the first game.  Crash 2 levels are about twice as large, have integrated bonus levels, multiple branches, “hard paths,” and three or four times as many creatures, each with an order of magnitude more settable parameters.  The overall turn around time for changing tunable level information was brought down significantly.

Technical/Design risk: can we make a better more flexible camera?

The camera was one of the things in Crash 1 with which we were least satisfied.  So in order to open up the game and make it feel more lifelike, we allowed the camera to look around much more, and supported a much wider set of branching and transition cameras.  In addition, arbitrary parameterized information was added to the camera system so that at any location the camera had more than 100 possible settable options.

If the two games are compared side by side, it can be seen that the overall layouts of Crash 2 levels are much larger and more complicated.  The camera is more natural and fluid, and there are numerous dynamic camera transitions and effects which were not present in the first game.  Even though the Crash 2 camera was written entirely from scratch, the lessons learned during the course of Crash 1 allowed it to be more sophisticated and aggressive, and it executed faster than its predecessor.

Optimization risk: can we put more on screen?

Crash 1 was one of the fastest games of its generation, delivering high detail images at 30 frames per second.  Nevertheless, for Crash 2 we wanted to put twice as much on screen, yet still maintain that frame-rate.  In order to achieve this goal we had one programmer doing nothing but re-coding areas of the engine into better assembly for the entire length of the project.  Dramatically increasing performance does not just mean moving instructions around; it is a complex and involved process.  First we study the performance of all relevant areas of the hardware in a scientific and systematic fashion.  Profiles are made of cache latencies, coprocessor parallel processing constraints, etc.  Game data structures are then carefully rearranged to aid the engine in loading and processing them in the most efficient way.  Complicated compression and caching schemes are explored to both reduce storage size (often linked to performance due to bus bandwidth) and to speed up the code.

Simultaneously we modularized the game engine to add more flexibility and features.  Crash 2 has more effects, such as Z-buffer-like water effects, weather, reflections, particles, talking hologram heads, etc.  Many annoying limitations of the Crash 1 drawing pipeline were removed, and most importantly, the overall speed was increased by more than two-fold.

In order to further improve performance and allow more simultaneous creatures on screen, we re-coded the GOOL interpreter into assembly, and also modified the compiler to produce native MIPS assembly for even better performance.

Technical risk: if we can put more on screen, can we fit it in memory?

We firmly believe that all three Crash games make use of the CD in a more aggressive fashion than most Playstation games.  So in order to fit the even larger Crash 2 levels into memory (often up to 12 megabytes a level) we had to increase the efficiency of the virtual memory scheme even more.  To do so we rewrote the AI that lays out the CD, employing several new algorithms.  Since different levels need different solutions we created a system by which the program could automatically try different approaches with different parameters, and then pick the best one.

In addition, since Crash 2 has about 8 times the animation of the first game, we needed to really reduce the size of the data without sacrificing the quality of the animation.  After numerous rewrites the animation was stored as a special bitstream compressed in all 4 dimensions.

Design risk: can we deliver a gameplay experience that is more than just “additional levels of Crash?”

We believe that game sequels are more than an opportunity to just go “back to the bank.”  For both of the Crash sequels we tried to give the player a new game, that while very much in the same style, was empirically a bigger, better game.  So with the increased capacity of the new Crash 2 engine we attempted to build larger more interesting levels with a greater variety of gameplay, and a more even and carefully constructed level of difficulty progression.  Crash 2 has about twice as many creatures as Crash 1, and their behaviors are significantly more sophisticated.  For example, instead of just putting the original “turtle” back into the game, we added two new and improved turtles, which had all the attributes of the Crash 1 turtle, but also had some additional differences and features.  In this manner we tried to build on the work from the first game.

Crash himself remains the best example.  In the second game Crash retains all of the moves from the first, but gains a number of interesting additional moves: crawling, ducking, sliding, belly flopping, plus dozens of custom coded animated death sequences.  Additionally, Crash has a number of new control specs: ice, surfboard, jet-pack, baby bear riding, underground digging, and hanging.  These mechanics provide entirely new game machines to help increase the variety and fun factor of the game.  It would be very difficult to include all of these in a first generation game because so much time is spent refining the basic mechanic.

Technically, these additions and enhancements were aided by the new more flexible information specification of the new tools pipeline, and by additions to the GOOL programming language based on lessons learned from the first game.

Crash Bandicoot: Warped!  –   Every trick in the book!

Development: January 1998 – November 1998

Staff: 15 people: 3 programmers, 7 artists, 3 designers, 2 support

Premise: With only 9 months in which to finish by Christmas, we gave ourselves the challenge of making a third Crash game which would be even cooler and more fun than the previous one.  We chose a new time travel theme and wanted to differentiate the graphic look and really increase the amount and variety of gameplay.  This included power-ups, better bosses, lots of new control mechanics, an open look, and multiple playable characters.

Technical/Process risk: the tight deadline and a smaller programming staff required us to explore options for even greater efficiency.

The Crash Warped production schedule required that we complete a level every week.  This was nearly twice the rate typical of Crash levels.  In addition, many of the new levels for Warped required new engines or sub-engines designed to give them a more free-roaming 3D style.  In order to facilitate this process we wrote an interactive listener which allowed GOOL based game objects to be dynamically examined, debugged, and tuned.  We were then able to set the parameters and features of objects in real-time, greatly improving our ability to tune and debug levels.  Various other visual debugging and diagnostic techniques were also introduced as well.

Knowledge from the previous game allowed us to further pipeline various processes.  The Crash series is heavily localized for different territories.  The European version supports five languages, text and speech, including lip sync.  In addition, it was entirely re-timed, and the animation was resampled for 25hz.  The Japanese version has Pocketstation support, a complete language translation, and a number of additional country specific features.  We were able to build in the features needed to make this happen as we wrote the US version of the game.  The GOOL language was expanded to allow near automatic conversion of character control timing for PAL.

Technical/Art risk: could the trademark look of the Crash series be opened up to offer long distance views and to deliver levels with free-roaming style gameplay?

In order to further differentiate the third Crash game, we modified the engine to support long distance views and Level of Detail (LOD) features.  Crash Warped has a much more open look than the previous games, with views up to ten times as far.  The background polygon resource manager needed some serious reworking in order to handle this kind of increased polygon load, as did the AI memory manager.  We developed the new LOD system to help manage these distance views.  These kinds of system complexities would not have been feasible in a first generation game, since when we started Crash 1, the concept of LOD in games was almost completely undeveloped, and just getting a general engine working was enough of a technical hurdle.

Similarly, the stability of the main engine allowed us to concentrate more programmer time on creating and polishing the new sub-engines:  jet-ski, motorcycle, and biplane.

Gameplay risk: could we make the gameplay in the new Crash significantly different from the previous ones and yet maintain the good elements of the first two games?

The new free-roaming style levels presented a great gameplay challenge.  We felt it necessary to maintain the fast-paced, forward driven Crash style of gameplay even in this new context.  The jet-ski in particular represented a new kind of level that was not present in the first two games.  It is part race game, part vehicle game, and part regular Crash level.  By combining familiar elements like the boxes and creatures with the new mechanics, we could add to the gameplay variety without sacrificing the consistency of the game.

In addition to jet-ski, biplane, and motorcycle levels, we also added a number of other new mechanics (swimming, bazooka, baby T-rex, etc.) and brought back most of Crash 2’s extensive control set.  We tried to give each level one or more special hooks by adding gameplay and effect features.  Warped has nearly twice as many different creatures and gameplay modes as Crash 2.  The third game clocked in at 122,000 lines of GOOL object control code, as compared to 68,000 for the second game and 49,000 for the first!  The stability of the basic system and the proven technical structure allowed the programmers to concentrate on gameplay features, packing more fun into the game.  This was only possible because on a fixed hardware like the Playstation, we were fairly confident that the Warped engine was reasonably optimal for the Crash style of game.  Had we been making the game for a moving target such as the PC, we would have been forced to spend significant time updating to match the new target, and would have not been able to focus on gameplay.

Furthermore, we had time, even with such a tight schedule, to add more game longevity features.  The Japanese version of Warped has Pocketstation support.  We improved the quality of the boss characters significantly, improved the tuning of the game, added power-ups that can be taken back to previously played levels, and added a cool new time trial mode.  Crash games have always had two modes of play for each level: completion (represented by crystals) and box completion (represented by gems).  In Warped we added the time trial mode (represented by relics).  This innovative new gameplay mode allows players to compete against themselves, each other, and preset goals in the area of timed level completion.  Because of this each level has much more replay value and it takes more than twice as long to complete Warped with 100% as it does Crash 2.

Technical risk: more more more!

As usual, we felt the need to add lots more to the new game.  Since most of Crash 2’s animations were still appropriate, we concentrated on adding new ones.  Warped has a unique animated death for nearly every way in which Crash can loose a life.  It has several times again the animation of the second game.  In addition, we added new effects like the arbitrary water surface, and large scale water effects.  Every character, including Crash got a fancy new shadow that mirrors the animated shape of the character.

All these additions forced us to squeeze even harder to get the levels into memory.  Additional code overlays, redundant code mergers, and the sacrifice of thirteen polka dotted goats to the level compression AI were necessary.

Conclusions

In conclusion, the consistency of the console hardware platform over its lifetime allows the developer an opportunity to successively improve his or her code, taking advantage of techniques and knowledge learned by themselves and others.  With each additional game the amount of basic infrastructure programming that must be done is reduced, and so more energy can be put into other pursuits, such as graphical and gameplay refinements.

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Yet more Crash Bandicoot posts can be found here.

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Crash Bandicoot – Teaching an Old Dog New Bits – part 1

This is loosely part of a now lengthy series of posts on the making of Crash Bandicoot. Click here for the PREVIOUS or for the FIRST POST .

Below is another journal article I wrote on making Crash in 1999. This was co-written with Naughty Dog uber-programmer Stephen White, who was my co-lead on Crash 2, Crash 3, Jak & Daxter, and Jak 2. It’s long, so I’m breaking it into three parts.

 

Teaching an Old Dog New Bits

How Console Developers are Able to Improve Performance When the Hardware Hasn’t Changed

by

Andrew S. Gavin

and

Stephen White

Copyright © 1994-99 Andrew Gavin, Stephen White, and Naughty Dog, Inc. All rights reserved.

 

Console vs. Computer

Personal computers and video game consoles have both made tremendous strides in graphics and audio performance; however, despite these similarities there is a tremendous benefit in understanding some important differences between these two platforms.

Evolution is a good thing, right?

The ability to evolve is the cornerstone behind the long-term success of the IBM PC.  Tremendous effort has been taken on the PC so that individual components of the hardware could be replaced as they become inefficient or obsolete, while still maintaining compatibility with existing software.  This modularity of the various PC components allows the user to custom build a PC to fit specific needs.  While this is a big advantage in general, this flexibility can be a tremendous disadvantage for developing video games.  It is the lack of evolution; the virtual immutability of the console hardware that is the greatest advantage to developing high quality, easy to use video game software.

You can choose any flavor, as long as it’s vanilla

The price of the PC’s evolutionary ability comes at the cost of dealing with incompatibility issues through customized drivers and standardization.  In the past, it was up to the video game developer to try to write custom code to support as many of the PC configurations as possible.  This was a time consuming and expensive process, and regardless of how thorough the developer tried to be, there were always some PC configurations that still had compatibility problems.  With the popularity of Microsoft’s window based operating systems, video game developers have been given the more palatable option of allowing other companies to develop the drivers and deal with the bulk of the incompatibility issues; however, this is hardly a panacea, since this necessitates a reliance on “unknown” and difficult to benchmark code, as well as API’s that are designed more for compatibility than optimal performance.  The inherit cost of compatibility is compromise.  The API code must compromise to support the largest amount of hardware configurations, and likewise, hardware manufacturers make compromises in their hardware design in order to adapt well to the current standards of the API.  Also, both the API and the hardware manufacturers have to compromise because of the physical limitations of the PC’s hardware itself, such as bus speed issues.

Who’s in charge here?

The operating system of a PC is quite large and complicated, and is designed to be a powerful and extensively featured multi-tasking environment.  In order to support a wide variety of software applications over a wide range of computer configurations, the operating system is designed as a series of layers that distance the software application from the hardware.  These layers of abstraction are useful for allowing a software application to function without concerning itself with the specifics of the hardware.  This is an exceptionally useful way of maintaining compatibility between hardware and software, but is unfortunately not very efficient with respect to performance.  The hardware of a computer is simply a set of interconnected electronic devices.  To theoretically maximize the performance of a computer’s hardware, the software application should write directly to the computer’s hardware, and should not share the resources of the hardware, including the CPU, with any other applications.  This would maximize the performance of a video game, but would be in direct conflict with the implementations of today’s modern PC operating systems.  Even if the operating system could be circumvented, it would then fall upon the video game to be able to support the enormous variety of hardware devices and possible configurations, and would therefore be impractical.

It looked much better on my friend’s PC

Another problem with having a large variety of hardware is that the video game developer cannot reliably predict a user’s personal set-up.  This lack of information means that a game can not be easily tailored to exploit the strengths and circumvent the weaknesses of a particular system.  For example, if all PC’s had hard-drives that were all equally very fast, then a game could be created that relied on having a fast hard-drive.  Similarly, if all PC’s had equally slow hard-drives, but had a lot of memory, then a game could compensate for the lack of hard-drive speed through various techniques, such as caching data in RAM or pre-loading data into RAM.  Likewise, if all PC’s had fast hard-drives, and not much memory, then the hard-drive could compensate for the lack of much memory by keeping most of the game on the hard-drive, and only spooling in data as needed.

Another good example is the difference between polygon rendering capabilities.  There is an enormous variation in both performance and effects between hardware assisted polygonal rendering, such that both the look of rendered polygons and the amount of polygons that can be rendered in a given amount of time can vary greatly between different machines.  The look of polygons could be made consistent by rendering the polygons purely through software, however, the rendering of polygons is very CPU intensive, so may be impractical since less polygons can be drawn, and the CPU has less bandwidth to perform other functions, such as game logic and collision detection.

Other bottlenecks include CD drives, CPU speeds, co-processors, memory access speeds, CPU caches, sound effect capabilities, music capabilities, game controllers, and modem speeds to name a few.

Although many PC video game programmers have made valiant attempts to make their games adapt at run-time to the computers that they are run on, it is difficult for a developer to offer much more than simple cosmetic enhancements, audio additions, or speed improvements.  Even if the developer had the game perform various benchmark tests before entering the actual game code, it would be very difficult, and not to mention limiting to the design of a game, for the developer to write code that could efficiently structurally adapt itself to the results of the benchmark.

Which button fires?

A subtle, yet important problem is the large variety of video game controllers that have to be supported by the PC.  Having a wide variety of game controllers to choose from may seem at first to be a positive feature since having more seems like it should be better than having less, yet this variety actually has several negative and pervasive repercussions on game design.  One problem is that the game designer can not be certain that the user will have a controller with more than a couple of buttons.  Keys on the keyboard can be used as additional “buttons”, but this can be impractical or awkward for the user, and also may require that the user configure which operations are mapped to the buttons and keys.  Another problem is that the placement of the buttons with respect to each other is not known, so the designer doesn’t know what button arrangement is going to give the user the best gameplay experience.  This problem can be somewhat circumvented by allowing the user to remap the actions of the buttons, but this isn’t a perfect solution since the user doesn’t start out with an inherent knowledge of the best way to configure the buttons, so may choose and remain using an awkward button configuration.  Also, similar to the button layout, the designer doesn’t know the shape of the controller, so can’t be certain what types of button or controller actions might be uncomfortable to the user.

An additional problem associated with game controllers on the PC is that most PC’s that are sold are not bundled with a game controller.  This lack of having a standard, bundled controller means that a video game on the PC should either be designed to be controlled exclusively by the keyboard, or at the very least should allow the user to optionally use a keyboard rather than a game controller.  Not allowing the use of the keyboard reduces the base of users that may be interested in buying your game, but allowing the game to be played fully using the keyboard will potentially limit the game’s controls, and therefore limit the game’s overall design.

Of course, even if every PC did come bundled with a standard game controller, there would still be users who would want to use their own non-standard game controllers.  The difference, however, is that the non-standard game controllers would either be specific types of controllers, such as a steering wheel controller, or would be variations of the standard game controller, and would therefore include all of the functionality of the original controller.  The decision to use the non-standard controller over the standard controller would be a conscious decision made by the user, rather than an arbitrary decision made because there is no standard.

Chasing a moving target

Another problem associated with the PC’s evolutionary ability is that it is difficult to predict the performance of the final target platform.  The development of video games has become an expensive and time consuming endeavor, with budgets in the millions, and multi year schedules that are often unpredictable.  The PC video game developer has to predict the performance of the target machine far in advance of the release of the game, which is difficult indeed considering the volatility of schedules, and the rapid advancements in technology.  Underestimating the target can cause the game to seem dated or under-powered, and overestimating the target could limit the installed base of potential consumers.  Both could be costly mistakes.

Extinction vs. evolution

While PC’s have become more powerful through continual evolution, video game consoles advance suddenly with the appearance of an entirely new console onto the market.  As new consoles flourish, older consoles eventually lose popularity and fade away.  The life cycle of a console has a clearly defined beginning:  the launch of the console into the market.  The predicted date of the launch is normally announced well in advance of the launch, and video game development is begun early enough before the launch so that at least a handful of video game titles will be available when the console reaches the market.  The end of a console’s life cycle is far less clearly defined, and is sometimes defined to be the time when the hardware developer of the console announces that there will no longer be any internal support for that console.  A more practical definition is that the end of a console’s life cycle is when the public quits buying much software for that console.  Of course, the hardware developer would want to extend the life cycle of a console for as long as possible, but stiff competition in the market has caused hardware developers to often follow up the launch of a console by immediately working on the design of the next console.

Each and every one is exactly the same

Unlike PC’s which can vary wildly from computer to computer, consoles of a particular model are designed to be exactly the same.  Okay, so not exactly the same, but close enough that different revisions between the hardware generally only vary in minor ways that are usually pretty minor from the perspective of the video game developer, and are normally transparent to the user.  Also, the console comes with at least one standard game controller, and has standardized peripheral connections.

The general premise is that game software can be written with an understanding that the base hardware will remain consistent throughout the life-span of the console; therefore, a game can be tailored to both exploit the strengths of the hardware, and to circumvent the weaknesses.

The consistency of the hardware components allows a console to have a very small, low level operating system, and the video game developer is often given the ability to either talk to the hardware components directly, or to an extremely low hardware abstraction layer.

The performance of the components of the hardware is virtually identical for all consoles of a given model, such that the game will look the same and play the same on any console.  This allows the video game developer to design, implement, and test a video game on a small number of consoles, and be assured that the game will play virtually the same for all consoles.

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