Surprise! It’s not 2d!
Hi, I’m David Doran-Marshall, Lead Designer at Controlled Chaos. We’ve decided to roll back the curtain and share some of the development side of things with you, through blog posts like this.
I remember the fascination I had with games when my Dad showed me his game, Cylon. It was the early ’80′s, and I was young enough to have to sit on his lap to play his text-base space strategy game. He made it for fun, in between teaching classes. He finally showed me the code a few years ago, and it was like going back in time. That sense of wonder returned, but I realized that all of the hours I had put in on Cylon were for naught (the game is rigged so that you can never actually win).
So that’s the same experience that I hope we can deliver with this blog. Going back in time, sharing and explaining, and keeping you up to date with what we are actually working on. Plus you get some cool insights on how games are made.
totb
First, some history on Texting of the Bread. In 2010, ScrewAttack came to us, with the goal of making a game for their fans. The game was a mashup between the learn2type helpers you might find online, and the zombie craze that still hasn’t quite died off. More importantly, it was a direct homage of Typing of the Dead, Sega’s slightly strange remake of The House of The Dead. You type the word, and the zombie gets blasted.
Combining a mechanic that literally everyone should know how to do on the iPhone (typing), with zombies – sounds like fun. Plus, as a hardcore game, it fit well with ScrewAttack’s approach to the gaming community.
Viewing the game in a debug state reveals that it's 3d, made to look 2d.
Why not 2d?
We had a very short development window for ToTB. Games like this usually take many months with a small team, or can be done quickly, with a large team. We had 4 people and 2 months. The decision was made quickly to go with a 3d approach (some would call this 2.5d). Here is Mike Penrod, our Lead Artist, to explain:
“We had to go 3d because making sprites and character sheets for that many enemies would be impossible in that time. When you make a single character with sprites, adding just one new behavior can effectively double the amount of work you have. When it’s 3d, you are just dealing with the model, and a set of animations. We also needed character deformation, which we did by blowing off parts of the zombies at predefined locations. Using sprites, this would either be impossible, or require all of those sprites for every possible combination. Finally, we needed that big boss to come walking on the screen, and be able to bend down and attack the player. This could be done with sprites, but once we had a single gingerman zombie, we could start sharing base animations, saving a lot of time.”
Our plans for the bosses also included zooming backwards to allow the player to see the entire boss, and feel tiny by comparison. This unfortunately didn’t make it in to the final game, but if we added future content, it’s a possibility.
The tradeoff with being able to quickly create ~10 unique 3d enemies in that short amount of time was performance. The engine we used for ToTB (Shiva) has a great art pipeline, but its spawning of entities, ability to render many objects, and hud system is slow.
Dynamic Background
Personally, one of my favorite visual features in ToTB is the moving background. It shifts as the level plays, showing time lapse. Each wave is supposed to be a “day”, so as the game progresses, you’ll see the sky brighten, sun rise and set, and eventually be able to see the moon and stars. The trick of this is in the implementation.
By the time we were implementing the moving background, we were dealing with some very real optimization issues. We couldn’t load in a sun model and individual stars. We didn’t just want to accept the problems and resort to a static background. Again, Mike came up with the solution:
“The background is a system of overlapping planes, cut and UV-Mapped to appear as one single image. We then animate a large texture that scrolls across the model automatically in code. The texture was created to match up with the overlapping layers, so that the colors blend nicely together. We also use the same technique in one of the wave-loading screens. As you swipe your finger from tray to tray, you are basically pulling that texture over the model.”
As you can see from the picture, the texture itself is practically unrecognizable, taken out of context.
The texture used in totb's scrolling background models. Note yellow and red "fire" that could be seen in the distant burning buildings.
In The End
Techniques like this allowed us to ship ToTB. We deal in a fast-changing industry where you have to think on your toes to get the job done. Just like my Dad made Cylon impossible to win, we have to make these little decisions every single day as we work on a project. We hope to get more posts like this out soon. Until then, if you have any questions or devblog requests, send us an email, or join our online community. Thanks for stopping by.
ddm
