I have noticed that with several of my most recent projects I have had to deal with vector mathematics and matrix operations quite a lot. I used this form of mathematics in college, but it was never my strongest point.
However, after working on the Icarus Rocket Simulator, and on Artillery! I have developed what I feel is quite a good working knowledge of this kind of mathematics. This is part of the reason why I chose to work on these projects, I wanted to improve my skills in these areas. This form of mathematics is vital in computer games, particularly 3D computer games, and it is found in everything from physics, to rendering, to Artificial Intelligence, to weapons. It is impossible to scrape by without it.
Vectors are used, amongst other things, to determine the facing or rotation of an object. For example, if an ai player is to be programmed to turn in the direction of a player or a target, this is achieved by using the currect direction vector of the Ai Player and the position of the target. Vectors can also be used to do very interesting things with objects, such as simulate gravitational forces (simply apply a vector with magnitude 9.81 on the negative Z axis) or wind (basically the same thing, but apply the force to other axes). They can also be used to change the direction of projectiles in flight, creating curved projectiles, something I did for my Artillery game.
I have mostly used matrices for carrying out rotations and in rendering code. One of the models I used had a “muzzlepoint” node. This node was used to determine the direction that the muzzle of a gun was pointing. I accidentally rotated it by 90 degrees in my modelling tool, meaning the projectiles were being fired 90 degrees to one side. I could have simply rotated the muzzle point in the modelling tool and re-exported, but to test my skills I instead rotated it by using a matrix, and it worked perfectly!
This is the 90 degree rotation matrix:
This again, is a basic but very important skill.
I have a lot of ideas as to how I might use vectors and matrices in future, they are very useful tools, and now that I have a good commad of them I should be able to make some pretty cool things!
I am now coming close to achieving feature completion with this project.
I have added a menu which shows an analysis of the previous shot taken by the player, making it easier to adjust the settings for the subsequent shots. This allows the game world to be bigger, and shots to be taken over longer distances. This opens up the game, and provides for a more fun challenge.
I have also added improvements to the AI, allowing it to handle more variables, such as modifying the power of it’s shots as well as the rotation and elevation of the turret.
I have been working on the art for the game, and designing some new turrets and vehicles that will be used, as well as adding visual improvements such as visible player names, and various bug fixes.
Finally, I have added a simulation of wind forces to Artillery. Wind speed and direction can be set to vary between rounds, be constant for the entire game, or be turned off entirely. Having to deal with wind forces add a significant challenge to the game, particularly if it changes per round.
I have some more work to do to get all of the features I want into the game, and then I have the debugging and optimisations to do, followed by the rest of the art.
I lost quite a bit of time this week due to major system instabilities I was getting on my main work machine. I was getting frequent Blue Screens, with seemingly random causes. I initially assumed the problem was due to a problem with Flash on my firefox browser, because switching to Chrome actually fixed the problem for several days, but it then returned.
After downloading a very useful tool called “Blue Screen View” from Nirsoft, I could see that most of the BSOD turned out to be of the type “Page fault in Non Paged Area”, which indicates a RAM problem. I used the famous MemTest86+ t0 check every one of my 4 RAM sticks individually, and I found one stick which produced over 86 thousand errors just halfway through the first pass! After removing that stick of RAM the system is back to performing well, albeit with just 6GB of RAM instead of 8.
Unfortunately, it is nearly impossible to buy RAM sticks individually, you almost always have to buy sticks in sets, so I have have to buy more than I need to get back to my preferred 8GB of RAM.
I thought this was worth posting about, since Blue Screens and RAM errors are both relatively common, and the aforementioned programs are invaluable in debugging and fixing them.
Below is a picture of the offending RAM stick. I don’t think Corsair Dominator is a bad brand, not at all, I have been a fan of Corsair memory for a long time. This is the only stick of RAM of theirs that has ever actually failed on me, and it’s about four years old.
This is an update on my latest game project, Artillery! This is also, incidentally, the first real post in my new blog!
The project is coming along well, I have completed the AI code, tested and debugged the network play feature, and I am currently finishing up the random level creator.
I have also added support for three different types of projectiles: Standard projectiles, which follow a simple ballistic trajectory, curved projectiles which, as the name suggests, can be made to follow a curved path specifed by the user, and cluster projectiles, which split into a cluster of warheads at the apex of their trajectory.
The random level creator will be designed to not only randomly place players, but also randomly place objects in their path, which will have to be taken into account when firing. This is where more unusual weapons like curved shots come into play, sometimes, to hit an enemy, you may need to curve a projectile around an obstacle.
I have also dome some work on the camera system, which will automatically update the position of the camera depending on where the action is, and I have added a compass to the currently selected player, to aid in aiming.
![R(90) = delim{[}{matrix{2}{2}{0 -1 1 0}}{]}](https://phoenixgamedevelopment.com/blog/wp-content/plugins/wpmathpub/phpmathpublisher/img/math_966.5_5d0260551cd827e128c013f925d91b4f.png "R(90) = delim{[}{matrix{2}{2}{0 -1 1 0}}{]}")
