i have been looking into an effective way to simulate a camera in as3. everywhere i have read have basically told me the same thing; dont move the character, just move the stage around it.
ok, that works for simple things. but what happens when you want to zoom in? simply inflating objects doesnt work, because distances fluctuate and movement values suddenly arent to scale.
is there an effective way to work around this? vcams (virtual cameras) seem like an easy alternative, but from my research, i cant afford that memory
One easy solution is to just scale the entire instance of the game itself.
So, create an instance of the game's class, just like you normally would, and center it on the stage.
Then use scaleX and scaleY to make the instance of the game look bigger. The game will still behave like it should and you won't need to adjust the movement values or anything like that.
Related
I am building a survival horror like game and am hoping to make a very nice camera system to compliment the mechanics. Part of this is the fact that you will be able to crouch down and cover your face. The camera work I want to do with this is to zoom in to the character in order to constrain the view for the player as well.
The current MC structure that I have is:
GameMaster
>
Spawner (this is for the player and all enemies)
>
Player
The issue I'm having is that scaling the GameMaster (which is where side scrolling and other global game effects are happening) causes the centering of the camera to offset based on how far away the player is from 0,0.
You can see the issue clearly in this video. The red arrows point to the 0,0.
On this stackoverflow question the answer says to make a container for everything and center the containers 0,0 over the target that you want to zoom around. This poses a challenge for me because I would then have to get proper coordinates for an object nested 4 MC's in. I'm also unsure what that will then do for my current side scrolling camera.
Is there a way that I could mathematically figure out the offset when the character ducks? It seems like a viable option because you can't move until you let go of crouch and the camera zooms out.
If not, is the container MC a good option or is it just one of those "you gotta do what you gotta do." type situations?
[Added]
I also see something about Transform Matrices or something. Is that something that would work? I know NOTHING about them but I assume they are CPU heavy and wouldn't be a good option for a mechanic prevalent throughout the whole game.
[Added 2]
ALSO, I want to do a rotation camera effect that suffers from the same 0,0 issue. Blatantly showing up as the player and level rotating around some far off pivot point.
If a Transform Matrix can swiftly and functionally offset the 0,0 to the players location so that I can do all the camera effects and alterations. I think that may be the best way to go.
----Close to Conclusion----
In regards to Vespers answer. Would I then be able to tween the resulting transform?
If so then that completely answers my entire problem. If not, I have no clue how to get the result I want.
I think the container is the cleanest solution. Since it'll be centered on the player, rotations and scaling will work normally. You mention getting the coordinates for the nested MC is hard, but there is a built-in function to do exactly that: localToGlobal()
To get the player position in global coordinates, just do player.localToGlobal(new Point(0, 0)). This should return the Player's center in global coordinates. If your main container is not in global coordinates (because it's nested inside another transformed MC, for example), you can use the opposite function on the container to convert from global to local:
container.globalToLocal(player.localToGlobal(new Point(0, 0)))
Now you just need to center the container. That could also be used to simulate the camera movement. If you update the container position at every frame, it'll give the effect of the camera following the player.
I've got a problem in actionscript3 with moving large DisplayObject-s. When the size of the DisplayObject is quite large (more than screen size) the movement loses smoothness and it looks like the object starts jumping forward and backward, which overall looks very unpleasant.
Does anybody know the way to fix that? I am trying to make a sort of a race game, where I need to move the background sprite to make the illusion of movement.
Try turning on cacheAsBitmap. That may give you some performance improvements, especially if the object is static (doesn't have any animated bits in it). With AS3 and Flash Player 10 or newer you should be able to get smooth movement even with a large sprite. I've got several games that do it.
Have to agree with Laurent - it is probably better to split the background into small pieces and move them
I'm brand new to Flash (and game programming, really), but want to learn a bit of it. My overall learning project is to create a Monopoly clone in Flash. Unfortunately, I'm struggling to get over even my first hurdle - how to create the board graphically, and how then to deal with it in the code. So far, my thoughts are to break the board down into the different sizes of tiles (the normal property ones, the corner 4 and a large one for the middle section), then somehow place these all in the correct position relative to each other and keep that positioning correct as the pieces (and thus the camera view) move about the board. (And, hopefully some day have a zooming ability too...)
Is this a good approach, or is there a better one? Does anyone know where I can find a tutorial specifically on creating board games in Flash (any sort really, wouldn't have to be Monopoly but just a game that has a board which tokens move across - and preferably which has to pan as well).
Also, as an aside, is there any way to have a dynamically coloured rectangle in a flash MovieClip (like you can have dynamic textboxs)? I ask because it would be useful if there was, as I could generate every property tile with just one MovieClip which took a name, a value and a colour...
everything you describe here you can do pretty easily once you get the hang of component sprites. personally i would make a single sprite that will then hold all of the "tiles" in the game, this would allow you to "zoom" the board while keeping all the pieces relative:
if you create this parent to have an addTile() and getTile(index:int):Sprite method then you can easily push the tiles and retrieve them from an array, so that Go is at index 0, old kent road is at 1 etc. that way you can use a single integer value to determine the position of the player piece as you can then use getTile(int).x etc.
the position of the tiles themselves can be worked out relative to the others. if you have a tile that is 20px wide and 40px high then you can position the tile as x = index * 20 for the first row, after the initial 11, you need to rotate them all and then use the y index instead (rotation = 90; x = 11*20; y = (index-11)*20) this will depend exactly on your origin point of your Sprite.
to draw coloured boxes you use the graphics of the Sprite, there are plenty of tuts on API drawing out there, but here is a basic box of 10x10px:
var drawing:Sprite = new Sprite();
drawing.graphics.beginFill(0x0000FF);
drawing.graphics.drawRect(0, 0, 10, 10);
drawing.graphics.endFill();
Another approach to your question could be to learn about Object Oriented Programming. That may not solve your representing the board graphically straight away, but it would definitely help you structure your game.
With OOP, you could define a "Property" Class with a set of properties such as streetName , color , price etc... I haven't played Monopoly in a while but you can get the general idea, i.e. to create a base object and make it specific by setting the object's properties. Your question about the colored rectangle can actually apply to other properties, a great way to avoid unnecessary repetition.
Broadly speaking OOP tends to emulate real life situations, so you could actually look at your Monopoly game, break it into its various parts, find common properties etc... I won't start a lesson here :) I'd be pretty bad at it, but there's plenty of resources out there . Look for OOP, Design Patterns & Actionscript3.
After a little research, you may find that your question about how to handle graphics may not be such a problem after all.
Your questions are way too general. I'm sure you don't want us to walk you through your whole project right?
Now to gain some experience, I suggest to you simply work through a few flash gaming tutorials. There are a LOT of those, I googled for 2-3 seconds and found this:
http://pelfusion.com/tutorials/35-flash-game-development-tutorials-fla-files/
I'm sure you feel disappointed by this answer, but this is the first step in solving your own problems. The internet has more than enough general game tutorials already. If you have specific problems, we might be of better help to you.
I assume with dynamically colored rectangles, you mean simply changing the color during runtime. Well you simply give the rectangle a name, and change the color property of it in code. Like this: rectangle.Color = Something.
You might want to start out with a simpler project just to learn some of the basics, maybe a little game where the player has to move a rectangle from one side of the screen to the other using the arrow keys or mouse, upon which a score is incremented or something. This will help teach you how the coordinate system works, among other things.
To draw stuff using code, you can create a new Sprite or MovieClip object and use its graphics property to draw primitive shapes (rectangles, etc.) to it at runtime.
I'm creating a space game in actionscript/flex 3 (flash). The world is infinitely big, because there are no maps. For this to work I need to dynamically (programatically) render the background, which has to look like open space.
To make the world feel real and to make certain places look different than others, I must be able to add filters such as colour differences and maybe even a misty kind of transformation - these would then be randomly added and changed.
The player is able to "scroll" the "map" by flying to the sides of the screen, so that a certain part of the world is only visible at once but the player is able to go anywhere. The scrolling works by moving all objects except for the player in the opposite direction, making it look like it was the player that moved into that direction. The background also needs to be moved, but has to be different on the new discovered terrain (dynamically created).
Now my question is how I would do something like this, what kind of things do I need to use and how do I implement them? Performance also needs to be taken into account, as many more objects will be in the game.
You should only have views for objects that are within the visible area. You might want to use a quad tree for that.
The background should maybe be composed of a set of tiles, that you can repeat more or less randomly (do you really need a background, actually? wouldn't having some particles be enough?). Use the same technique here you use for the objects.
So in the end, you wind up having a model for objects and tiles or particles (that you would generate in the beginning). This way, you will only add a few floats (you can achieve additional performance, if you do not calculate positions of objects, that are FAR away. The quad tree should help you with that, but I think this shouldn't be necessary) If an object having a view leaves the stage, free the view, and use the quad tree to check, if new objects appear.
If you use a lot of objects/particles, consider using an object pool. If objects only move, and are not rotated/scaled, consider using DisplayObject::cacheAsBitmap.
Ok, so I'll try to be as descriptive as possible.
I'm working on a project for a client that requires a jibjab-style masking feature of an uploaded image.
I would like to be able to generate a database-storable object that contains anchor/control positions of a bezier shape, so I can pull it out later and re-mask the object. This all is pretty easy to do, except for one catch : I need to create the bezier object from a user-drawn outline.
So far, here's how I imagine the process going:
on mouse down, create a new sprite, beginFill, and moveTo mouse position.
on mouse move, lineTo an XY coordinate.
on mouse up, endFill.
This all works just great. I could just store the info here, but I would be looking at a GIGANTIC object full of tons of pretty useless x/y coordinates, and no way to really make fine-tuning changes outside of putting handles on every pixel. (I may as well give the end user a pencil tool...)
Here's what I'm thinking as far as bezier curve calculation goes :
1: Figure out when I need to start a new curve, and track the xy of the pixel on this interval. I'm imagining this being just a pixel count, maybe just increment a count variable per mouse move and make a new one every x pixels. The issue here is some curves would be inaccurate, and others unnecessary, but I really just need a general area, not an exact representation, so it could work. I'd be happier with something a little smarter though.
2: take each new x/y, store it as an anchor, and figure out where a control would go to make the line curve between this and the last anchor. this is where I get really hung up. I'm sure someone has done this in flash, but no amount of googling can seem to help me out with the way to get this done. I've done a lot of sketching and what little math I can wrap my brain around, but can't seem to figure out a way of converting pixels to beziers.
Is this possible? All I really need is something that will get close to the same shape. I'm thinking about maybe only placing anchors when the angle of the next pixel is beyond 180 degrees in relation to the current line or something, and just grabbing the edge of the arc between these changes, but no matter how hard I try, I can't seem to figure out how to get this working!
Thanks for your help, I'll be sure to post my progress here as I go, I think this could be really useful in many applications, as long as it's actually feasible...
Jesse
It sounds like a lot of work to turn pixels into Bezier curves. You could try using something like the Linear least squares algorithm. http://en.wikipedia.org/wiki/Linear_least_squares
A different tact, could you have your users draw vector graphics instead? That way you can just store the shapes in the database.
Another cool method of converting raster to vector would be something like this iterative program: http://rogeralsing.com/2008/12/07/genetic-programming-evolution-of-mona-lisa/
Good luck
In my answer to this question I discuss using autotrace to convert bitmaps to beziers. I recommend passing your user drawing through this program on the server. Autotrace does a fantastic job of tracing and simplifying so there is no need to try and reinvent the wheel here.
Thanks for the answers, although I guess I probably should be more specific about the application, I'm really only needing an outline for a mask, so converting images to vectors or polygons, despite how cool that is, doesn't really fix my issue. The linear least squares algorithm is mega cool, I think this might be closer to what I'm looking for.
I have a basic workaround going right now, I'm just counting mouse moves, then every X (playing with it to get most desirable curve) moves, I grab the xy position. then, I take every other stored xy, and turn it into an anchor, the remaining xys are turned into controls. This is producing somewhat desirable results, but has some minor issues, in that the speed at which the mask is drawn effects the number of handles, and it's really just getting a general area, not a precise fit.
Interestingly, users seem to draw slower for more precise shapes, so this solution works a lot better than I had imagined, but it's not as nice as it could be. This will work for the client, so although there's no reason to pursue it further, I like learning new things, and will spend some off the clock time looking into linear least equations and seeing if I can drum up a class that will do these computations for me. If anyone runs across some AS3 code for this type of thing, or would like some of mine, let me know, this is an interesting puzzle.