I'm programming a game using ActionScript 3.0 and included Box2D classes for its physics. It's a maze/labyrinth game having a lot of walls and a ball inside.
In my main fla when I call the maze.create(), the maze is created (visually and physically) and it will dispatch an event so I know when it's done working and then I call my frameHandler which calls another function from my maze class every frame and the big delay accrues exactly at world.step() in it. BUT THE THING IS that it lags only the first two times this function runs!!!
The reason I notice this lag, is that I've got another object starting to move according to mouse position in the same frame handler.
The reason I'm sure the world.step() is causing it, is that everything works fine when I dont call it.
I've seen many codes using Box2d, some had more objects than i have and I know that I've created my b2World and all the objects correctly, similar to all the Box2d tutorials and stuff BUT THEY DONT LAG AT ALL. Its just mine lagging and all!!
Do you have any Idea or similar experience?
Do you have any suggestion in general how to deal with heavy functions?
PLEEEEASE +.-
A maze will have a lot of fixtures in close proximity making a very dense dynamic tree (the method Box2D uses to optimize collision checks). There is unlikely to be any way around this. Perhaps you could just call Step a few times after adding the static walls, but before you add the dynamic ball bodies, and consider it part of the loading process. At least the lagging movements will not be visible to the player.
Related
I am developing some games with my friends, using Ogre3D and Bullet Physics.
I managed to get our game character moving (just simple run and turn).
I guess I can implement 'jumping' by this class:
btCollisionWorld::ClosestRayResultCallback res(btFrom, btTo);.
However, my big issue is collision optimization.
I tried:
adding 100~500 rigidbody objects (after we changed these to mapobject in our game)
one staticplanecollision object (ground)
one character rigidbody object
FPS for just moving on plane is 60~80 = ok. But when my character collides with any other rigidbody object, FPS is going down to 7.
I have no idea that fix this problem.
I am not useing DynamicCharacterController or KineticCharacterController.
Character is controlled by setLinearVelocity() and rigidbody->getWorldTransform().setRotation(quat) function
Some more information:
PhysicsManager::GetInstance()->getDynamicsWorld()->stepSimulation(evt.timeSinceLastFrame,8);
I've had this issue before, I don't know if that's your case, but we were implementing Damned (game), and when we modeled the kitchens we were using the stoves' meshes as collision objects (btDbvtTriangleMeshShape), and everytime the character got close to a stove the FPS went down...
The solution was to use a simple collision shape for each stove (like btCompound with a few boxes), and the FPS issue went away :)
Hope your issue is similar to this so you can solve it by reducing the complexity of the collision shapes you're using.
If this isn't the case, please, show me the code you run when handling your character (also, KinematicCharacterController is highly recommended, and moving from Bullet to PhysX is even more recommended ;D).
Best.
I'm a beginner to AS3 and programming in general, but have learned enough that I want to now start learning how to render animations on the screen. These are the methods that I know of from two days of "researching" on google.
I'm not in a situation where I could afford to take courses from an educational institution, so my only means of learning are through online sources.
Update an objects x or y positions in a loop on every frame. Very basic. Of course any kind of advanced animation (say, showing a character running) is not possible with this method alone.
Using Flash and creating animation on a movie clip's timeline and, combined with moving the position of the object we can achieve some proper animation this way. However I cannot afford Flash, so this is not an option available to me. It also doesn't seem to be a popular option among more experienced programmers either (I think, due to having poor performance when lots of objects animating on the screen?)
Using a sprite sheet and then blitting the relevant image from the sprite sheet onto the screen.
Is there any other way to put an image from a sprite sheet onto the screen other than blitting?
And what other methods of rendering animation are available?
Some online websites claim that blitting is all I'll ever need, but I want to know all the options available so I could choose the most appropriate one for any given situation.
Any help would be appreciated :)
Another option for blitting is Stage3D. Take a look at Starling for 2D animations.
Blitting would be my best opinion. The only other thing I can think of is manually taking the images from the sprite sheet and putting it into each frame of an animation.
To render animation, you can create a frame in a MovieClip and convert it into a MovieClip and name the frame 'running'. Then you need to create an Enter Frame event where the MovieClip's instance name is 'Guy' and in the code on the function write 'Guy.x += 5;' to make your MovieClip go 5 pixels to the right every frame and also in the function write "Guy.gotoAndStop('running');"
Use TweenMax engine for better animation purposes. Easy coding, more Animation!!
I have a problem with a game that I'm doing. I basically have objects that are in a map and I have to check for each of them if they collide with the walls (and then do something). Since was working with AS2, I thought about doing the same way: I drew a picture with only the walls, so with only rectangles and everything else in between is transparent (does not exist, then the floor for example). In AS2 I put the image to the screen, let's call it wall, and then I did a hitTest to wall with every object. That is for instance, the object was actually on the image, since that the transparent parts were part of it, but the function was testing only on the visible parts, and so with the walls. So it worked.
Now in AS3 there is no HitTest but hitTestObject, which I used, and I do for example wall.hitTestObject(object). The problem is that this function is as if it doens't see the transparencies, and the objects while not touching the walls collide with them!
I found the PixelPerfectCollisionDetection that actually solves the problem but it is huge and heavy so in my case, with so many objects to be tested (at least 60) at each frame, the game slows down a lot!
What I need is a function like hitTestObject (i don't need a lot of accuracy!) that take care of the transparent parts of an image.
How can I do?
As mentioned in the comments, physics/game libraries will have this code built-in for you and should work out of the box.
But if you want to build it yourself, or even introduce your own optimizations, the first step (which is very inexpensive) is checking for bounds collision using entirely built-in functionality of DisplayObject.getBounds and Rectangle.intersects (though you must do so in a consistent coordinate space, i.e. the stage):
if (obj1.getBounds(stage).intersects(obj2.getBounds(stage)) {
// Cheap bounds intersection is true, now do pixel-perfect detection...
}
Then if the bounds check is true, perform the pixel-perfect collision detection.
It seems that BitmapData.hitTest is your best bet - see a blog post by Mike Chambers.
Prior to this method, if you're interested in neat techniques, there was a method outlined by Grant Skinner in his blog. It's quite a clever algorithm using built-in bitmap routines (aka, fairly fast), creating a BitmapData only as large as the overlapping region (or even scaling that down), and drawing the two objects into specific channels of the bitmapdata, then using BitmapData.getColorBoundsRect() to determine if there are any pixels touch. I'm guessing BitmapData.hitTest is faster, but it'd be fun to compare.
I ran into the same problem and to be honest i found the easy way to get rid of that is just generating a "mask" layer for the collisions. You can always place this under your background so it doesn't show, or change the transparencies and whatsoever. Do this in Flash, and after "covering" with rectangles (or whatever) the collisions, just select them all and make that a movie clip.
I'm guessing since you made the symbol in Flash, it obviously knows that even if the symbol consists of several individual drawings or whatever, it's not just an image.
For me this worked fine .
Or that's what I think, at least.
I just began with AS3 and I'm trying to do a little game where one ball moves on its own and the other one is handled by the player. So far, so good. That works.
What isn't working is hitTestObject(); it just returns true when it's like 2 cm from the other object. Here's a picture so you can see: http://dl.dropbox.com/u/37057843/coll2.jpg
I've read that hitTestObject just creats a rectangle around the objects and then tests for collisions on those rectangles, is it because of that?
If you need any piece of code I'll deliver. I know there are some other opensource libraries/engines like Box2D to solve this in a better way, but I don't want to jump to engines directly.
Thanks for reading!
Yes, hitTestObject will use the clips bounding box.
Check out this link, it has a lot of great information as well as a class that will do what you're looking for
http://sierakowski.eu/list-of-tips/39-collision-detection-methods-hittest-and-hittestobject-alternatives.html
Direct link to the package
http://code.google.com/p/collisiondetectionkit/
I'm writing a card game in ActionScript 3. Each card is represented by an instance of a class extending movieclip exported from Flash CS4 that contains the card graphics and a flip animation. When I want to flip a card I call gotoAndPlay on this movieclip.
When the frame rate slows down all animations take longer to finish. It seems Flash will by default animate movieclips in a way that makes sure all frames in the clip will be drawn. Therefor, when the program frame rate goes below the frame rate of the clip, the animation will be played at a slower pace.
I would like to have an animation always play at the same speed and as a consequence always be shown on the screen for the same amount of time. If the frame rate is too slow to show all frames, frames are dropped. Is is possible to tell Flash to animate in this way? If not, what is the easiest way to program this behavior myself?
The easiest way would be to use a Timer (or a setInterval) triggering every 1000/fps milliseconds, telling your MovieClip to go to its next frame.
If you need something more accurate, you'll have to check the time spent since the last update (stolen from the first comment of this article from Keith Peters' blog, which explains everything pretty well).
It's been a while since I used Flash but from what I understand it's not possible because Flash uses a frame based animation model.
Silverlight however uses a time based animation model and will just draw as many intermediate frames as the frame-rate allows.
The tween class (fl.transitions.Tween) is perfect for this situation. By setting the last argument of the constructor to TRUE then it bases its animations/triggers off of seconds, and as far as I know it compensates for FPS loss/gain.
You can easily use it like the Timer class by passing a new object (Trigger(new Object(), "x") to the constructor and creating a listener for MOTION_FINISH (TweenEvent.MOTION_FINISH) to trigger your event!
I use Tweens for a LOT of things because they're easy, fast, and supported by everything. And like I said, it should solve your FPS/lag issues since it adjusts to FPS changes in real-time (as far as I know!).