Basic Java App with Android Studio

As the semester is coming to a close in console I chose to create a basic mobile application in Java. I have done some Java in the past however never for Mobile device. So looking at this I decided to try using Android Studio which had some reviews and go through the first tutorial. First looking at how easily the program linked with my nexus was great. Many applications I have used they have ran into some step where my computer and the nexus wouldn't connect and this walkthrough went through great.

From there I opened and created my first project. This is great between the XML and Java, they work so smooth together it is easy to define strings in the XML and than use them with your program using @ after defining it. I went through the basic Activity screen via the parent process so that one would call the other.

This took a bit and some steps on the walk through were left out or confusing, but the application went smooth and at the end got a basic app, that takes the text of the user and than outputs it into the other activity afterwards. Overall this was very fun and I see myself continuing the tutorial both for understanding Mobile development from something other than Unity and Action-script (All I have done in the past.) Also it will help me develop better Java skills, which I have written very little Java as a whole, and have heard many good things about the language.

Physics Rigid Body

Currently coming into the final Project, I ran into several problems and the largest one was time. Currently I have created the Rigid-Body, that knows a correct Update and has a gravity generator so the rigid-Sphere will fall. As well I have gone through multiple narrow checks in a collision detector class, that takes into sphere to plane all the way to box to box. However with my system as it currently can only take into an account for Sphere creation boxes in order to get textures I would have to create a whole graphics System. OpenGL has a nice sphere that allows easy texture adding in the basic functionality. My goal in the next few days is a hope of at least getting the collision detection and resolution for the ground. Currently there is Sphere to plane collision check. So I would need to give the Ground a CollisionPlane, and the Rigid-Sphere a CollisionSphere that it could check during frames to see when they collide. When they collide they create a collisionData. These Data's all get kept and than resolved every frame. This way if there are none, you do none, and if there are a 100 you do all 100. I also need to have a max and figure out per frame what are the most important and what can be put off til the next update. Doing 1k collisions per frame could hinder performance.

Alibi Generation

In one of my classes I took on using an AI application that would create Alibis at run time. When looking into the process itself is seem to use mostly statistic Algorithm to choose which alibi to create. So for this it mean saving a lot of numbers. The equation itself is Y = { 1/[ σ * sqrt(2π) ] } * e^{-(x - μ)2/2σ2 .} . Y is the percent chance at X and the sigma (o looking) is the standard deviation from the mean which is the  where μ is the mean, and σ is the standard deviation. The standard deviation is a normal amount above and below the mean value it would be alright with. So with this we see that we get a single Y value at X. Which means to get a true probability we need to do it many more times. For my generation I go up til I hit the Mean + Deviation. So 25 Characters with 5 deviation I go from 0 - 30 to calculate the first chance of creation. From that point You do from current to that max. So if 5 people were already alive to check the percentage of any number of people between 5 and 30. You would check for 6 - 30. Adding each one would give you a proper percent.

    public const float e = 2.71828f;
    //cumlative probabilty of ans < randVariable based on the mean and standDev
    //so if you wanted to know how long a light bulb would last for 1200 hours or less
    //the mean would be 1000 and dev would be 100
    // you would use CumlativeNormalDis(1200,1000,100) the percentage would be 97
    static public float NormalDis(float randVariable, float mean, float standDev)
    {
        float y = (float)1.0f / (standDev * (float)Math.Sqrt(2.0f * Math.PI));
        float z = -1 * (((randVariable - mean) * (randVariable - mean)) / (2.0f * standDev * standDev));
        float x = e;
        x = (float)Math.Pow(x, z);
        y = y * x;
     
        return y;
    }

    //--------------------------------------------------------------------------------------------
    static public float CumlativeNormalDis(float randVariable, float mean, float standDev)
    {
        float ans = 0;
        for(int i = 0; i < randVariable;i++)
        {
            ans += NormalDis(i, mean, standDev);
        }
        return ans * 100;
    }

This is specifically my two function in order to create the percentage from 0 - 100 cumulatively. As well I leave a comment above on how to use it. You can see how this would be time consuming. Running this equation over and over just to get a percent between 0 - 1. Now imagine with everything on top of this creating full alibis for a character would take time. Luckily you would be doing a sector or even just a current location. You would want to keep the alibis to a smaller amount. Never try to create 1000 full alibis for all character.

I chose full alibi above, when I use full I mean not only are we deciding how this certain character would look like, but some background some likes dislikes, this way if we allow communication between the player and say this NPC, he would actually know why he was standing where he was. He choose lets say to grab a coffee from place X over place Y and the player watched him walk from right next to the other place all the way to X. With just random pathing there is no reason for him other than looking good to make him walk. However if he has an alibi that states he loves the scones from this place and hates the coffee from the other he actually has a reason(an alibi) to go through the extra walking.

Now if I was to put this into a full game I envision, some would need to be created live like why they are pathing to a location. However some of the background looks, and some likes and dislikes could be created before and left in groups. This way you have a couple option to put in an area. So each say grid space you would create at once has 3-4 variations saved. This way they were run before the game was even shipped and this would save a lot of time and allow that to be used in the game. However the use during is still feasible and the ability to take these alibis later and populate an area to a reasonable amount not having too many or too few people at one time can help trick a player.

As well very detailed alibis help create this layer of confusion, was this character built, have a seen him/her before, Or is this a new character, the player wouldn't be able to tell unless he remember and talked to every player he has ever met. This also allows a proper flow of character that look like they belong somewhere in the game. It keeps characters that don't look like they belong in lets say a library from a library and those who would be there go there. It adds a nice level of belief to the player when he walks through an open world. Overall I believe using these alibis is extremely helpful to a player, to fully immerse in the world. When they talk to anyone and they have the alibis and background on their life it looks like the world is real. If you walked up and got a generic hello for hundredth time it can break the immersion. You as a developer can go as deep into the alibi pool as possible even giving details on work, and personal history of the character in the world. You can go as little as a suit or tee-shirt.

Physics Rods, Cables, and Springs

Currently I have completed a simulation for Rods, Cables, Springs, and contact generators at the particles level. I noticed during the quick implementation of OpenGL and the graphics system built on top caused some frame-rate issues. I needed to go back and re-factor the way the images got processed and streamlined it into a class, which is more efficient for numerous reasons. In these pictures the player being the ball is following around a cube, put together of Rods, so that it doesn't lose its shape.

Above you see a diamond like shape that has fallen because it has 3 sides in the middle not 4. In a perfect simulation a 4 sided diamond would stand perfectly on a particle because all forces would hit equilibrium once it landed on the ground. As you look at the pictures the camera is slightly off of where the ball is and it's because currently the camera is based off of a physics object attached to the players. So sudden moves and stopping causes a little elastic motion for the player.  In the bottom you can see the wall which all physics object bounce off of including the camera. This iteration I also took the time to set it up by game objects which render, and physics objects which just update collide etc. This also increased performance, and allowed the camera to have physics without having to fake render anything. Current shapes that can be rapidly created by my physics implementation are cubes, triangular pyramids, and triangular diamonds. These can be quickly created by the level, just by creating and setting a center point and the width of the total object. It will figure the rest out and easily set-up cables, rods, or springs depending on what you would have wanted.

Physics Solar System

In our physics Engine class the past couple weeks we had to create a Planetary Simulation. This project also allowed me to get into OpenGL, and is the first time I have used it. In order to create everything I use a Force Generator which which takes scaled numbers to calculate the gravity equation G * (m1* m2) / r^2 r being the distance between them. In order to produce it on a screen 1 distance in openGl is the same as the distance from the Sun to the earth. As for Mass 1 is a solar mass so the mass of the sun. As well all planets are scaled properly except for the earth moon and sun. The Sun would eat Mercury and Venus if proper, as well the Earth is too large and you would be unable to see the moon. The initial distance is also the heliocentric position which is when it is closest to the sun. This location has a given velocity which is a percentage of the earths initial velocity which is given. If you failed to give an initial velocity in the y or z, it would just be all eaten by the sun. The velocities and accelerations on bottom are scaled by 10 ^ 9 so they can be seen on the GLUI. For this project I use GLUI for the UI and I use SOIL in order to load images into a graphics section of the planets and simple skybox.

The video software states that its running at one FPS, but that text is just an error with the video. It would be a lot worse at one FPS, because I have a DPF which is days per second because I have a game timer in my simulation. This way a loss in frame rate doesn't slow the simulation down itself. So when my when an update occurs it runs through the physics system, that many times between 0 and 150 which are the min and max. This way it does the math day by day instead of just doing it one large jump which would cause a lot of errors, both floating points and getting correct velocity and acceleration for each section. Since I am using euler physics there are errors overtime, some calculations were done before putting it into the system so it would round less and I could use doubles for maths, but save as floats. However there is some rounding and just using the general gravity does not produce a perfect simulation. If I was going to take this farther I would use Keplers' laws of planetary motion to create a better simulation, but it would have required a lot more time than I had.

Abyssi Production 2 Project

This is my groups production two final project. It is a horror based game with the player being reliant on his flashlight for everything. In order to play you use wasd to move, as well as shift to sprint, control to crouch, e to interact with objects like extra batteries generators and anything that can be opened. As we developed this game we gave the users shaders on all interaction objects, but the web format will not keep the shaders as of now and if you full screen doors may not fully open, our group is working on that as we speak.
I personally was in charge of the AI and a lot of game testing. I enjoyed and feel that how they two enemies came out went very well. One who is attracted to light if you shine it on him and one who is afraid of the light. Using A* node pathfinding I allowed designers to have the enemies only roam area's they wanted them to do as well as go to different spots every play through. The could place nodes around the whole map and dictate node maps that held whichever nodes they wanted. From this they would just give that node to an AI member and he only knew about that region.

Sights and Sound

In production 1 of early times I worked on another project that went extremely well and the group I feel worked flawlessly with each other. Again I worked with a another programmer. This time my other Programmer was Alex Beauchesne, my designer was Devon Case, and Artists were Kristin Darling and Caitlin Coon  For this project when something was needed or necessary our group never had a problem meeting or talking at all times of the day, which really helped this game which had just a few weeks get extremely far and work very well. We were told to make an educational game so what we went was, teaching children how to solve puzzles using another character which you switch between and eventually would be two player and each would help and control one of them. Each had abilities which the other didn't and these were strengths the other lacked. For this game we had a character who had earmuffs stuck to his air so he was technically deaf and the other had a bandanna over her eyes, so she was technically blind and they used the other member sense the lacked to make it through the course. The game progressively moves the player forward and has introductions and teaches the player how to use each player through the first few levels then requires the player to use the past until you get to a real level with no new activities and you are put to the test.