How create an unfinished jump game? - android

i want to create an unfinished jump game. i use super jumper code. the main part for change height of world is :
while (y < WORLD_HEIGHT - WORLD_WIDTH / 2) {
...
y += (maxJumpHeight - 0.5f);
y -= rand.nextFloat() * (maxJumpHeight / 3);
}
if i change while condition to a big number(for example 100 or 1000), fps goes low(i get lag).
i try many things. but i couldn't reach to a correct answer.
if someone can, help me.
(sorry for my english...)

Changing
while (y < WORLD_HEIGHT - WORLD_WIDTH / 2) {
to
while (y < WORLD_HEIGHT * 100) {
in Super Jumper's World.generateLevel will generate a lot more content, but won't actually make the level longer (the display system will only display up to WORLD_HEIGHT, and the end-of-level Castle will still be in the same place.
If you want to make a very large level, change the definition of WORLD_HEIGHT itself. Its currently set to about 20 screens worth of platforms.
The reason the game slows down when you make the levels larger is probably because all the per-frame update and collision detection code uses a linear scan of all the elements. For small levels, this is fine, but if you have very large levels, this won't scale. However, I'm just guessing, and you should probably run the profiler to figure out where all the time is being spent.

Related

Constant and probably inaccurate Frame Rate

I am using the following code to calculate Frame Rate in Unity3d 4.0. It's applied on a NGUI label.
void Update () {
timeleft -= Time.deltaTime;
accum += Time.timeScale/Time.deltaTime;
++frames;
// Interval ended - update GUI text and start new interval
if( timeleft <= 0.0 )
{
// display two fractional digits (f2 format)
float fps = accum/frames;
string format = System.String.Format("{0:F2} FPS",fps);
FPSLabel.text = format;
timeleft = updateInterval;
accum = 0.0F;
frames = 0;
}
}
It was working previously, or at least seemed to be working.Then I was having some problem with physics, so I changed the fixed timestep to 0.005 and the Max timestep to 0.017 . Yeah I know it's too low, but my game is working fine on that.
Now the problem is the above FPS code returns 58.82 all the time. I've checked on separate devices (Android). It just doesn't budge. I thought it might be correct, but when I saw profiler, I can clearly see ups and downs there. So obviously it's something fishy.
Am I doing something wrong? I copied the code from somewhere (must be from the script wiki). Is there any other way to know the correct FPS?
By taking cues from this questions, I've tried all methods in the first answer. Even the following code is returning a constant 58.82 FPS. It's happening in the android device only. In the editor I can see fps difference.
float fps = 1.0f/Time.deltaTime;
So I checked the value of Time.deltaTime and it's 0.017 constant in the device. How can this be possible :-/
It seems to me that the fps counter is correct and the FPS of 58.82 is caused by the changes in your physics time settings. The physics engine probably cannot finish its computation in the available timestep (0.005, which is very low), and that means it will keep computing until it reaches the maximum timestep, which in your case is 0.017. That means all frames will take 0.017 plus any other overhead from rendering / scripts you may have. And 1 / 0.017 equals exactly 58.82.
Maybe you can fix any problems you have with the physics in other ways, without lowering the fixed timestep so much.

How to collide objects with high speed in Unity

I try to create game for Android and I have problem with high speed objects, they don't wanna to collide.
I have Sphere with Sphere Collider and Bouncy material, and RigidBody with this param (Gravity=false, Interpolate=Interpolate, Collision Detection = Continuous Dynamic)
Also I have 3 walls with Box Collider and Bouncy material.
This is my code for Sphere
function IncreaseBallVelocity() {
rigidbody.velocity *= 1.05;
}
function Awake () {
rigidbody.AddForce(4, 4, 0, ForceMode.Impulse);
InvokeRepeating("IncreaseBallVelocity", 2, 2);
}
In project Settings I set: "Min Penetration For Penalty Force"=0.001, "Solver Interation Count"=50
When I play on the start it work fine (it bounces) but when speed go to high, Sphere just passes the wall.
Can anyone help me?
Thanks.
Edited
var hit : RaycastHit;
var mainGameScript : MainGame;
var particles_splash : GameObject;
function Awake () {
rigidbody.AddForce(4, 4, 0, ForceMode.Impulse);
InvokeRepeating("IncreaseBallVelocity", 2, 2);
}
function Update() {
if (rigidbody.SweepTest(transform.forward, hit, 0.5))
Debug.Log(hit.distance + "mts distance to obstacle");
if(transform.position.y < -3) {
mainGameScript.GameOver();
//Application.LoadLevel("Menu");
}
}
function IncreaseBallVelocity() {
rigidbody.velocity *= 1.05;
}
function OnCollisionEnter(collision : Collision) {
Instantiate(particles_splash, transform.position, transform.rotation);
}
EDITED added more info
Fixed Timestep = 0.02 Maximum Allowed Tir = 0.333
There is no difference between running the game in editor player and on Android
No. It looks OK when I set 0.01
My Paddle is Box Collider without Rigidbody, walls are the same
There are all in same layer (when speed is normal it all works) value in PhysicsManager are the default (same like in image) exept "Solver Interation Co..." = 50
No. When I change speed it pass other wall
I am using standard cube but I expand/shrink it to fit my screen and other objects, when I expand wall more then it's OK it bouncing
No. It's simple project simple example from Video http://www.youtube.com/watch?v=edfd1HJmKPY
I don't use gravity
See:
Similar SO Question
A community script that uses ray tracing to help manage fast objects
UnityAnswers post leading to the script in (2)
You could also try changing the fixed time step for physics. The smaller this value, the more times Unity calculates the physics of a scene. But be warned, making this value too small, say <= 0.005, will likely result in an unstable game, especially on a portable device.
The script above is best for bullets or small objects. You can manually force rigid body collisions tests:
public class example : MonoBehaviour {
public RaycastHit hit;
void Update() {
if (rigidbody.SweepTest(transform.forward, out hit, 10))
Debug.Log(hit.distance + "mts distance to obstacle");
}
}
I think the main problem is the manipulation of Rigidbody's velocity. I would try the following to solve the problem.
Redesign your code to ensure that IncreaseBallVelocity and every other manipulation of Rigidbody is called within FixedUpdate. Check that there are no other manipulations to Transform.position.
Try to replace setting velocity directly by using AddForce or similar methods so the physics engine has a higher chance to calculate all dependencies.
If there are more items (main player character, ...) involved related to the physics calculation, ensure that their code runs in FixedUpdate too.
Another point I stumbled upon were meshes that are scaled very much. Having a GameObject with scale <= 0.01 or >= 100 has definitely a negative impact on physics calculation. According to the docs and this Unity forum entry from one of the gurus you should avoid Transform.scale values != 1
Still not happy? OK then the next test is starting with high velocities but no acceleration. At this phase we want to know, if the high velocity itself or the acceleration is to blame for the problem. It would be interesting to know the velocities' values at which the physics engine starts to fail - please post them so that we can compare them.
EDIT: Some more things to investigate
6.7 m/sec does not sound that much so that I guess there is a special reason or a combination of reasons why things go wrong.
Is your Maximum Allowed Timestep high enough? For testing I suggest 5 to 10x Fixed Timestep. Note that this might kill the frame rate but that can be dfixed later.
Is there any difference between running the game in editor player and on Android?
Did you notice any drops in frame rate because of the 0.01 FixedTimestep? This would indicate that the physics engine might be in trouble.
Could it be that there are static colliders (objects having a collider but no Rigidbody) that are moved around or manipulated otherwise? This would cause heavy recalculations within PhysX.
What about the layers: Are all walls on the same layer resp. are the involved layers are configured appropriately in collision detection matrix?
Does the no-bounce effect always happen at the same wall? If so, can you just copy the 1st wall and put it in place of the second one to see if there is something wrong with this specific wall.
If not to much effort, I would try to set up some standard cubes as walls just to be sure that transform.scale is not to blame for it (I made really bad experience with this).
Do you manipulate gravity or TimeManager.timeScale from within a script?
BTW: are you using gravity? (Should be no problem just

Android Game Development: Collision Detection Failing

I am currently developing a game for Android, and I would like your expertise on an issue that I have been having.
Background:
My game incorporates frame rate independent motion, which takes into
account the delta time value before performing necessary Velocity
calculations.
The game is a traditional 2D platformer.
The Issue:
Here's my issue (simplified). Let's pretend that my character is a square standing on top of a platform (with "gravity" being a constant downward velocity of characterVelocityDown).
I have defined the collision detection as follows (assuming Y axis points downwards):
Given characterFootY is the y-coordinate of the base of my square character, platformSurfaceY is the upper y-coordinate of my platform, and platformBaseY is the lower y-coordinate of my platform:
if (characterFootY + characterVelocityDown > platformSurfaceY && characterFootY + characterDy < platformBaseY) {
//Collision Is True
characterFootY = platformSurfaceY;
characterVelocityDown = 0;
} else{
characterVelocityDown = deltaTime * 6;
This approach works perfectly fine when the game is running at regular speed; however, if the game slows down, the deltaTime (which is the elapsed time between the previous frame and the current frame) becomes large, and characterFootY + characterVelocityDown exceed the boundaries that define collision detection and the character just falls straight through (as if teleporting).
How should I approach this issue to prevent this?
Thanks in advance for your help and I am looking forward to learning from you!
What you need to do is to run your physics loop with constant delta time and iterate it as many time as it need with current tick.
const float PHYSICS_TICK = 1/60.f; // 60 FPS
void Update( float dt )
{
m_dt += dt;
while( m_dt > PHYSICS_TICK )
{
UpdatePhysics( PHYSICS_TICK );
m_dt -= PHYSICS_TICK;
}
}
There are various technics used to handle the tick left ( m_dt )
Caps for miniumum tick and maximum tick are also a must.
I guess the issue here is that slowdowns are inevitable. You can try and optimize the code but you'll always have users with slow devices or busy sections of your game where it takes a little longer than usual to process it all. Instead of assuming a consistent delta, assume the opposite. Code under the realization that someone could try installing it on an abacus.
So basically, as SeveN says, make your game loop handle slowdowns. The only real way to do this (in my admittedly limited experience) would be to place a cap on how large delta can be. This will result in your clock not running on time exactly, but when you think about it, that's how most games handle slowdown. You don't fire up StarCraft on your pentium 66 and have it run at 5 FPS but full speed, it slow down and processes it as normal, albeit at a slideshow.
If you did such a thing, during periods of slowdown in your game, it'd visibly slow down... but the calculations should still all be spot on.
edit: just realised you're SeveN. Well done.

Does having variations of gestures in gesture library improve recognition?

I'm working on implementing gesture recognition in my app, using the Gestures Builder to create a library of gestures. I'm wondering if having multiple variations of a gesture will help or hinder recognition (or performance). For example, I want to recognize a circular gesture. I'm going to have at least two variations - one for a clockwise circle, and one for counterclockwise, with the same semantic meaning so that the user doesn't have to think about it. However, I'm wondering if it would be desirable to save several gestures for each direction, for example, of various radii, or with different shapes that are "close enough" - like egg shapes, ellipses, etc., including different angular rotations of each. Anybody have experience with this?
OK, after some experimenation and reading of the android source, I've learned a little... First, it appears that I don't necessarily have to worry about creating different gestures in my gesture library to cover different angular rotations or directions (clockwise/counterclockwise) of my circular gesture. By default, a GestureStore uses a sequence type of SEQUENCE_SENSITIVE (meaning that the starting point and ending points matter), and an orientation style of ORIENTATION_SENSITIVE (meaning that the rotational angle matters). However, these defaults can be overridden with 'setOrientationStyle(ORIENTATION_INVARIANT)' and setSequenceType(SEQUENCE_INVARIANT).
Furthermore, to quote from the comments in the source... "when SEQUENCE_SENSITIVE is used, only single stroke gestures are currently allowed" and "ORIENTATION_SENSITIVE and ORIENTATION_INVARIANT are only for SEQUENCE_SENSITIVE gestures".
Interestingly, ORIENTATION_SENSITIVE appears to mean more than just "orientation matters". It's value is 2, and the comments associated with it and some related (undocumented) constants imply that you can request different levels of sensitivity.
// at most 2 directions can be recognized
public static final int ORIENTATION_SENSITIVE = 2;
// at most 4 directions can be recognized
static final int ORIENTATION_SENSITIVE_4 = 4;
// at most 8 directions can be recognized
static final int ORIENTATION_SENSITIVE_8 = 8;
During a call to GestureLibary.recognize(), the orientation type value (1, 2, 4, or 8) is passed through to GestureUtils.minimumCosineDistance() as the parameter numOrientations, whereupon some calculations are performed that are above my pay grade (see below). If someone can explain this, I'm interested. I get that it is calculating the angular difference between two gestures, but I don't understand the way it's using the numOrientations parameter. My expectation is that if I specify a value of 2, it finds the minimum distance between gesture A and two variations of gesture B -- one variation being "normal B", and the other being B spun around 180 degrees. Thus, I would expect a value of 8 would consider 8 variations of B, spaced 45 degrees apart. However, even though I don't fully understand the math below, it doesn't look to me like a numOrientations value of 4 or 8 is used directly in any calculations, although values greater than 2 do result in a distinct code path. Maybe that's why those other values are undocumented.
/**
* Calculates the "minimum" cosine distance between two instances.
*
* #param vector1
* #param vector2
* #param numOrientations the maximum number of orientation allowed
* #return the distance between the two instances (between 0 and Math.PI)
*/
static float minimumCosineDistance(float[] vector1, float[] vector2, int numOrientations) {
final int len = vector1.length;
float a = 0;
float b = 0;
for (int i = 0; i < len; i += 2) {
a += vector1[i] * vector2[i] + vector1[i + 1] * vector2[i + 1];
b += vector1[i] * vector2[i + 1] - vector1[i + 1] * vector2[i];
}
if (a != 0) {
final float tan = b/a;
final double angle = Math.atan(tan);
if (numOrientations > 2 && Math.abs(angle) >= Math.PI / numOrientations) {
return (float) Math.acos(a);
} else {
final double cosine = Math.cos(angle);
final double sine = cosine * tan;
return (float) Math.acos(a * cosine + b * sine);
}
} else {
return (float) Math.PI / 2;
}
}
Based on my reading, I theorized that the simplest and best approach would be to have one stored circular gesture, setting the sequence type and orientation to invariant. That way, anything circular should match pretty well, regardless of direction or orientation. So I tried that, and it did return high scores (in the range of about 25 to 70) for pretty much anything remotely resembling a circle. However, it also returned scores of 20 or so for gestures that were not even close to circular (horizontal lines, V shapes, etc.). So, I didn't feel good about the separation between what should be matches and what should not. What seems to be working best is to have two stored gestures, one in each direction, and using SEQUENCE_SENSITIVE in conjunction with ORIENTATION_INVARIANT. That's giving me scores of 2.5 or higher for anything vaguely circular, but scores below 1 (or no matches at all) for gestures that are not circular.

Issues with screen sizes and activity rendering

I'm currently developing my first android app, and my first game. I've been developing on a netbook with a CliqXT (HVGA). Things are going well, it renders perfectly on the smaller screen. I knew I'd have some issues when rendering on larger screens, but the issues I'm having are not what I was expecting and I'm kind of stuck.
So basically the game consists of a main SurfaceView which I'm rendering the tiled game world on to. I followed this tutorial to get started, and my structure is still pretty similar except that it calculates the boundries based on the player location:
http://www.droidnova.com/create-a-scrollable-map-with-cells-part-i,654.html
The game also has various buildings the player can enter. Upon entering it launches another activity for that particular building. The building activities are just normal Views with Android UI stuff defined in XML (Buttons, TextViews, etc).
What I expected to happen:
So I expected the the building UIs to render correctly on the larger screen. I specified all dimensions in "dp" and fonts in "sp" in hopes that they'd scale correctly. I expected the actual game tilemap to render generally correctly, but maybe be really tiny due to the higher resolution / dpi. I'm using a very similar function to the tutorial linked above (calculateLoopBorders(), my version is pasted below) to calculate how many tiles to render based on screen height and width (getHeight() and getWidth()).
What is actually happening:
The whole game is just being rendered as if it's HVGA. The tilemap, and the building UIs are just scaled down to the smaller screen size, leaving black borders around the left, right, and bottom (see images).
If anyone can point me in the right direction it'd be greatly appreciated, thanks a lot!
(Some of you may recognize this public domain DOS classic)
Edit: Thanks Christian for fixing code formatting.
mCellHeight and mCellWidth are the width/height of the cells in pixels
mMapHeight and mMapWidth are the width/height of the total game world in number of tiles
public void calculateLoopBorders() {
mWidth = getWidth();
mHeight = getHeight();
mStartRow = (int) Math.max(0, mPlayer.mRow - ((int) (mHeight / 2) / mCellHeight));
mStartCol = (int) Math.max(0, mPlayer.mCol - ((int) (mWidth / 2) / mCellWidth));
mMaxRow = (int) Math.min(mMapHeight, mStartRow + (mHeight / mCellHeight)) + 1;
mMaxCol = (int) Math.min(mMapWidth, mStartCol + (mWidth / mCellWidth));
if (mMaxCol >= mMapWidth) {
mStartCol = mMaxCol - (mWidth / mCellWidth);
}
if (mMaxRow >= mMapHeight) {
mStartRow = mMaxRow - (mHeight / mCellHeight);
}
int x1 = mStartCol * mCellWidth;
int y1 = mStartRow * mCellHeight;
int x2 = x1 + mWidth;
int y2 = y1 + mHeight;
mBgSrcRect = new Rect(x1, y1, x2, y2);
mBgDestRect = new Rect(0,0, mWidth, mHeight);
}
I figured it out. I was targeting 1.5 in the Project so it was assuming HVGA. Targeting 2.1 fixes the issue and the bitmaps even seem to scale correctly using some kind of android magic.
I still have a question though, when I finish this game I want it to work with 1.5+ devices. Do I need to put separate builds into the market, one for each device class? This seems like a lot of trouble for something that could be handled in a line or 2 of code in the app itself... but I've never released an app so maybe it's easily handled in the process.

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