Quick note: Due to me being caught up in a lot of technical work this blog entry is a lil bit late and I also missed a horror tip last week. Gonna try and be better in the future! :)
The fourth part in the puzzle series will be about a specific "feature" that I am sure you are all aware of. Backtracking. This is often to considered to be a big problem in adventure games and seem to especially plague survival horror like Resident Evil. It is often blamed for being a product of bad design, and it can often be very annoying. Backtracking does not always need to be bad though and might actually be a part in increasing the immersion.
To start up, I would like to define the different kinds of backtracking:
Compulsory backtracking
In some games, the design forces the player to do backtracking and games like Resident Evil and the newer Castlevania are full of this. After collecting a certain item, the player needs to backtrack to a location far back where the item is to be used. Sometimes the location is known (for example highlighted on a map) and other times it is up to player to figure out where to use the item. To make the journey back more fun, some games add new enemies, obstacles and/or change the environment. Other times the player simple needs to grind their way back. Especially when the target location is unknown it can be a very frustrating experience and I know of times in Castlevania where I pretty much searched through the entire game before finding out where the newly found item was to be used.
Forgotten item backtracking
Adventure games are often based around the player exploring environments and when much searching is needed, chances are something will be missed. This can lead to the player not having picked up an important item, done a certain task, etc and when arriving at an obstacle one needs to backtrack to find out what was missed. This type is different from the compulsory backtracking in that it is not explicitly designed, but stems from the fact a player has not been successful when searching. This situation can be very annoying to end up in as it might not be obvious where to look for the missing item/event. In many adventure games the player is some kind of scrap-collector and the usability of an item is not obvious until collected (if even then...). Thus it is hard to get any hints from the examining obstacle one is stuck at.
In my opinion the forgotten item type of backtracking is the most annoying and not always predictable from a design standpoint. Because of that I am going to discuss how to go around solving this first, and will be using Braid as an example. In Braid it is always possible to solve a puzzle when encountered as no items or upgrades are needed in order to find the correct solution. Instead the player needs to come up ingenious ways of using the game mechanics and sometimes simpler puzzles need to be solved in order figure a harder one out. When encountering a puzzle the player is always certain that a puzzle can be solved and can never be missing any special item or triggered event. This approach is a an "extreme" way of solving the missing item problem in that it never relies on previous areas (note: Braid does rely on it in on a single occasion).
But what if one wants to pick up items and such as part of the gameplay? A way to solving this is either to let force-feed the player with items, placing them in such obvious location that they are impossible to use and/or have sub obstacles that require the a certain event to be triggered for the player to continue. Many action adventure games uses this approach. Another way to deal with it is to always place the items close to the obstacle and removing the need to do any backtracking. This approach is what we used a lot in the Penumbra games and it requires that the player knows that items are always close (something we did not totally succeed with) . If the player still thinks that the needed item might be anywhere, then it does not matter that it in reality is very close. Also, this approach requires 100% consistency and if some puzzle suddenly requires an item way back, the player will still assume it is nearby and never go searching far enough. Finally making the puzzle solutions more "realistic" and intuitive will also improve the situation as the player can then easier figure out what might be needed for overcoming the obstacle.
Although there exist solutions for the forgotten item backtracking problem, they are not without flaws. On the other hand, with the compulsory backtracking it is easy to fix. Just remove the need of backtracking, right? On closer inspection, it turns out that it is not that easy. First of all, in open ended games there is a need to spread out puzzles and will therefore always be some kind of backtracking. The problem of not knowing where to go can still be addressed though and many open ended games has a map with blinking hot spots, arrows, etc indicating where the player should go. However, sometimes this is not wanted either and the enjoyment of the game might come from exploring the game without being spoon-fed the next action all the time.
Going back to Braid, which even though it does not have the forgotten item problem, still has some compulsory backtracking. Unless the player solves all of the puzzles in linear fashion, there is a need to go back through levels and find the last puzzle pieces needed. Now Braid could have let the player instantly teleport through some menu to each location, but in my opinion that would ruin the game. By being forced to traverse the world one is more immersed in the game world and even though the activity is not fun in itself, it still enhances the experience. To be fair, Braid has very minor backtracking compared to other games, but I still think it is an important observation.
Back to the forgotten item backtracking. Is this really always a bad thing? As mentioned in the solutions for overcoming it, a remedy mostly means limiting the player somehow and forcing one through the game. Limits can be a good thing, but if a game should give the player a feeling of exploration then it is almost impossible to remove it. Having some type of frustration is most likely essential in order to provide the right experience. The problem does not lie in removing the frustration, but rather limiting and managing it.
To sum things up: the problem of backtracking that at first glance just seems like an annoyance, might actually be a very important part of making a game. A designer should not try and remove the frustration caused by backtracking, but instead limit it and use it to improve the player experience. Frustration is a large part of life and just trying to remove it from a game will only result a brainless and less satisfying experience.
As always we are very curious to know what you think about all this!
This is when no parallax effect is added, just boring and flat. What happens is that the engine simple interpolates the uv-coordinate (the position on the texture map) according to the vertices (the points) of the model.
This algorithm is a lot more accurate than offset mapping, but also a lot more expensive. This is no longer a cheap trick and works by casting a ray from the position of the eye and into the height map. It is then computed where the ray first hit something and the uv coordinate of that point is used. This sort of ray casting is used in all advanced parallax techniques, but is implemented differently. In relief mapping, one first steps along the ray at certain intervals and looks for an intersection. When one is found a binary search is used between the intersection and the eye position to pin point the exact intersection point. The binary search means that the distance between eye and the first found position is halved over and over, locking in on the intersection.
