Below is a screenshot from a famous structure building game.
As you can see rods are attached together with ball joints. I'm trying to achieve something similar with Cosos2d on iPhone. I've got two questions here:
Should I draw those ball joints or should I just add them as sprites?
I guess the rods are not drawn bur are rather images. But considering that the length of the rods will change depending on need, how do I make rods with different lengths from just one image?
I am not sure what would be the best approach for one. I would imagine that either way would be fine, but it would be harder to achieve whatever visual affect you want through drawing them. I think the hardest part would be making sure that they are anchored to vertices in a grid system that has the dimension that you want.
As for (2) you can always scale your image.
CCSprite *rod = [CCSprite spriteWithFile:#"rod.png"];
rod.scaleY = 2.0; //or scaleX
Then rotate and change its anchor points as needed.
Again I imagine the most difficult part would be anchoring them and positioning them correctly, so that align properly with the vertices.
Related
I need to be able to interact with a representation of a cilinder that has many different parts in it. When the users taps over on of the small rectangles, I need to display a popover related to the specific piece (form).
The next image demonstrates a realistic 3d approach. But, I repeat, I need to solve the problem, the 3d is NOT required (would be really cool though). A representation that complies the functional needs will suffice.
The info about the parts to make the drawing comes from an API (size, position, etc)
I dont need it to be realistic really. The simplest aproximation would be to show a cilinder in a 2d representation, like a rectangle made out of interactable small rectangles.
So, as I mentioned, I think there are (as I see it) two opposite approaches: Realistic or Simplified
Is there a way to achieve a nice solution in the middle? What libraries, components, frameworks that I should look into?
My research has led me to SceneKit, but I still dont know if I will be able to interact with it. Interaction is a very important part as I need to display a popover when the user taps on any small rectangle over the cylinder.
Thanks
You don't need any special frameworks to achieve an interaction like this. This effect can be achieved with standard UIKit and UIView and a little trigonometry. You can actually draw exactly your example image using 2D math and drawing. My answer is not an exact formula but involves thinking about how the shapes are defined and break the problem down into manageable steps.
A cylinder can be defined by two offset circles representing the end pieces, connected at their radii. I will use an orthographic projection meaning the cylinder doesn't appear smaller as the depth extends into the background (but you could adapt to perspective if needed). You could draw this with CoreGraphics in a UIView drawRect.
A square slice represents an angle piece of the circle, offset by an amount smaller than the length of the cylinder, but in the same direction, as in the following diagram (sorry for imprecise drawing).
This square slice you are interested in is the area outlined in solid red, outside the radius of the first circle, and inside the radius of the imaginary second circle (which is just offset from the first circle by whatever length you want the slice).
To draw this area you simply need to draw a path of the outline of each arc and connect the endpoints.
To check if a touch is inside one of these square slices:
Check if the touch point is between angle a from the origin at a.
Check if the touch point is outside the radius of the inside circle.
Check if the touch point is inside the radius of the outside circle. (Note what this means if the circles are more than a radius apart.)
To find a point to display the popover you could average the end points on the slice or find the middle angle between the two edges and offset by half the distance.
Theoretically, doing this in Scene Kit with either SpriteKit or UIKit Popovers is ideal.
However Scene Kit (and Sprite Kit) seem to be in a state of flux wherein nobody from Apple is communicating with users about the raft of issues folks are currently having with both. From relatively stable and performant Sprite Kit in iOS 8.4 to a lot of lost performance in iOS 9 seems common. Scene Kit simply doesn't seem finished, and the documentation and community are both nearly non-existent as a result.
That being said... the theory is this:
Material IDs are what's used in traditional 3D apps to define areas of an object that have different materials. Somehow these Material IDs are called "elements" in SceneKit. I haven't been able to find much more about this.
It should be possible to detect the "element" that's underneath a touch on an object, and respond accordingly. You should even be able to change the state/nature of the material on that element to indicate it's the currently selected.
When wanting a smooth, well rounded cylinder as per your example, start with a cylinder that's made of only enough segments to describe/define the material IDs you need for your "rectangular" sections to be touched.
Later you can add a smoothing operation to the cylinder to make it round, and all the extra smoothing geometry in each quadrant of unique material ID should be responsive, regardless of how you add this extra detail to smooth the presentation of the cylinder.
Idea for the "Simplified" version:
if this representation is okey, you can use a UICollectionView.
Each cell can have a defined size thanks to
collectionView:layout:sizeForItemAtIndexPath:
Then each cell of the collection could be a small rectangle representing a
touchable part of the cylinder.
and using
collectionView:(UICollectionView *)collectionView
didSelectItemAtIndexPath:(NSIndexPath *)indexPath
To get the touch.
This will help you to display the popover at the right place:
CGRect rect = [collectionView layoutAttributesForItemAtIndexPath:indexPath].frame;
Finally, you can choose the appropriate popover (if the app has to work on iPhone) here:
https://www.cocoacontrols.com/search?q=popover
Not perfect, but i think this is efficient!
Yes, SceneKit.
When user perform a touch event, that mean you knew the 2D coordinate on screen, so your only decision is to popover a view or not, even a 3D model is not exist.
First, we can logically split the requirement into two pieces, determine the touching segment, showing right "color" in each segment.
I think the use of 3D model is to determine which piece of data to show in your case if I don't get you wrong. In that case, the SCNView's hit test method will do most of work for you. What you should do is to perform a hit test, take out the hit node and the hit's local 3D coordinate of this node, you can then calculate which segment is hit by this touch and do the decision.
Now how to draw the surface of the cylinder would be the only left question, right? There are various ways to do, for example simply paint each image you need and programmatically and attach it to the cylinder's material or have your image files on disk and use as material for the cylinder ...
I think the problem would be basically solved.
I've imported a vector layer from a psd into paint code v1, I'm trying to create a background image and make it universal.
I can't seem to add a frame around the vector, to complicate matters, I only need a portion, the center, of the layer. (The design is based around a circle, it has lines drawn towards the center of the circle.)
I can’t seem to add a frame to dynamically resize the part I need.
I found this http://www.raywenderlich.com/36341/paintcode-tutorial-dynamic-buttons the part about frame ans groups doesn't help me....
When I add a click frame and drag it around the area I need, it's at the same level as the vector layer. I've also tried adding a group around both, but that doesn't seem to obey the frame size either.
I’ve looked through the tutorials and googled adding a frame, but I can’t seem to achieve what I need.
EDIT
A frame is supposed to be at the same level as the vectors you're working with.
All you do then is set the resize rules of your vectors. There is a little rectangle in the frame's parameters interface with straight arrows and springs that you can modify to fit your wishes.
I think I also remember a checkbox setting to resize only what's inside the frame.
Now I haven't used PaintCode for a while, but if this doesn't help you, there probably is a problem with your vector layer.
I don't know if this information helps.
But if you resizing doesn't work as you expected. Look carefully at the transformation box (the one with the springs attached). When you have put a frame around your object. The middle dot in this box should be blue instead of green. if t's green, you may have a problem with the originating point of your objects and then the resizing may not work as you expected.
So I am trying to get a very basic "flashlight"-style thing going in one of my games.
The way I was getting it to work, was having a layer on top of my game screen, and this layer would draw a black rectangle with ~ 80% opacity, creating the look of darkness on top of my game scene.
ccDrawSolidRect(ccp(0,0), ccp(480,320), ccc4f(0, 0, 0, 0.8));
What I want to do is draw this rectangle EVERYWHERE on the screen, except for around a cone of vision that will represent the "light source".
What this would create would be a dark overlay on top of everything except for the light, giving it the illusion of a torch/light/flashlight.
The only way I can foresee this happening is by using ccDrawSolidPoly(), but since the position of the light source changes, so would the vertices for the poly.
Any suggestions on how to achieve this would be great.
You can use ccDrawSolidPoly() and avoid having to manually update vertices. For this you can create a new subclass of CCNode representing your light object, and do your custom shape drawing in its -(void)draw method.
The ccDraw...() functions will draw relative to the local sprite coordinates, so you can then move and rotate your new sprite to suit your needs and cocos2d will do the vertices transformations for you.
Update: I found out that you might be better off subclassing CCDrawNode instead of CCNode, as it has some facilities for raw OpenGL drawing (OpenGL's vertexArrayBuffer and vertexBufferObject internal variables and a buffer for vertices, their colors and their texCoords). If your stuff is very simple, maybe subclassing the plain CCNode is enough.
Could a png be used instead as a mask, as the layer above
Like that binocular vision you sometimes see in cartoons?
Or a filter similar to a photoshop mask that darkens as it grows outwardly to wards the edge of the screen
Just a thought anyway...
A picture of more of what your trying to explain might be good too
I have written a 2D Jump&Run Engine resulting in a 320x224 (320x240) image. To maintain the old school "pixely"-feel to it, I would like to scale the resulting image by 2 or 3 or 4, according to the resolution of the user.
I don't want to scale each and every sprite, but the resulting image!
Thanks in advance :)
Bob's answer is correct about changing the filtering mode to TextureFilter.Point to keep things nice and pixelated.
But possibly a better method than scaling each sprite (as you'd also have to scale the position of each sprite) is to just pass a matrix to SpriteBatch.Begin, like so:
sb.Begin(/* first three parameters */, Matrix.CreateScale(4f));
That will give you the scaling you want without having to modify all your draw calls.
However it is worth noting that, if you use floating-point offsets in your game, you will end up with things not aligned to pixel boundaries after you scale up (with either method).
There are two solutions to this. The first is to have a function like this:
public static Vector2 Floor(Vector2 v)
{
return new Vector2((float)Math.Floor(v.X), (float)Math.Floor(v.Y));
}
And then pass your position through that function every time you draw a sprite. Although this might not work if your sprites use any rotation or offsets. And again you'll be back to modifying every single draw call.
The "correct" way to do this, if you want a plain point-wise scale-up of your whole scene, is to draw your scene to a render target at the original size. And then draw your render target to screen, scaled up (with TextureFilter.Point).
The function you want to look at is GraphicsDevice.SetRenderTarget. This MSDN article might be worth reading. If you're on or moving to XNA 4.0, this might be worth reading.
I couldn't find a simpler XNA sample for this quickly, but the Bloom Postprocess sample uses a render target that it then applies a blur shader to. You could simply ignore the shader entirely and just do the scale-up.
You could use a pixelation effect. Draw to a RenderTarget2D, then draw the result to the screen using a Pixel Shader. There's a tool called Shazzam Shader Editor that let's you try out pixel shaders and it includes one that does pixelation:
http://shazzam-tool.com/
This may not be what you wanted, but it could be good for allowing a high-resolution mode and for having the same effect no matter what resolution was used...
I'm not exactly sure what you mean by "resulting in ... an image" but if you mean your end result is a texture then you can draw that to the screen and set a scale:
spriteBatch.Draw(texture, position, source, color, rotation, origin, scale, effects, depth);
Just replace the scale with whatever number you want (2, 3, or 4). I do something similar but scale per sprite and not the resulting image. If you mean something else let me know and I'll try to help.
XNA defaults to anti-aliasing the scaled image. If you want to retain the pixelated goodness you'll need to draw in immediate sort mode and set some additional parameters:
spriteBatch.Begin(SpriteBlendMode.AlphaBlend, SpriteSortMode.Immediate, SaveStateMode.None);
GraphicsDevice.SamplerStates[0].MagFilter = TextureFilter.Point;
GraphicsDevice.SamplerStates[0].MinFilter = TextureFilter.Point;
GraphicsDevice.SamplerStates[0].MipFilter = TextureFilter.Point;
It's either the Point or the None TextureFilter. I'm at work so I'm trying to remember off the top of my head. I'll confirm one way or the other later today.
I am using XNA for a 2D project. I have a problem and I don't know which way to solve it. I have a texture (an image) that is drawn to the screen for example:
|+++|+++|
|---|---|
|+++|+++|
Now I want to be able to destroy part of that structure/image so that it looks like:
|+++|
|---|---|
|+++|+++|
so that collision now will work as well for the new image.
Which way would be better to solve this problem:
Swap the whole texture with another texture, that is transparent in the places where it is destroyed.
Use some trickery with spriteBatch.Draw(sourceRectangle, destinationRectangle) to get the desired rectangles drawn, and also do collision checking with this somehow.
Split the texture into 4 smaller textures each of which will be responsible for it's own drawing/collision detection.
Use some other smart-ass way I don't know about.
Any help would be appreciated. Let me know if you need more clarification/examples.
EDIT: To clarify I'll provide an example of usage for this.
Imagine a 4x4 piece of wall that when shot at, a little 1x1 part of it is destroyed.
I'll take the third option:
3 - Split the texture into 4 smaller
textures each of which will be
responsible for it's own
drawing/collision detection.
It's not hard do to. Basically it's just the same of TileSet struct. However, you'll need to change your code to fit this approach.
Read a little about Tiles on: http://www-cs-students.stanford.edu/~amitp/gameprog.html#tiles
Many sites and book said about Tiles and how to use it to build game worlds. But you can use this logic to everything which the whole is compost from little parts.
Let me quick note the other options:
1 - Swap the whole texture with
another texture, that is transparent
in the places where it is destroyed.
No.. have a different image to every different position is bad. If you need to change de texture? Will you remake every image again?
2- Use some trickery with
spriteBatch.Draw(sourceRectangle,
destinationRectangle) to get the
desired rectangles drawn, and also do
collision checking with this somehow.
Unfortunately it's don't work because spriteBatch.Draw only works with Rectangles :(
4 Use some other smart-ass way I don't
know about.
I can't imagine any magic to this. Maybe, you can use another image to make masks. But it's extremely processing-expensive.
Check out this article at Ziggyware. It is about Deformable Terrain, and might be what you are looking for. Essentially, the technique involves settings the pixels you want to hide to transparent.
Option #3 will work.
A more robust system (if you don't want to be limited to boxes) would use per-pixel collision detection. The process basically works as follows:
Calculate a bounding box (or circle) for each object
Check to see if two objects overlap
For each overlap, blit the sprites onto a hidden surface, comparing pixel values as you go. If a pixel is already set when you try to draw the pixel from the second sprite, you have a collision.
Here's a good XNA example (another Ziggyware article, actually): 2D Per Pixel Collision Detection
Some more links:
Can someone explain per-pixel collision detection
XNA 2-d per-pixel collision
I ended up choosing option 3.
Basically I have a Tile class that contains a texture and dimention. Dimention n means that there are n*n subtiles within that tile. I also have an array that keeps track of which tiles are destroyed or not. My class looks like this in pseudo code:
class Tile
texture
dimention
int [,] subtiles; //0 or 1 for each subtile
public Tile() // constructor
subtiles = new int[dimention, dimention];
intialize_subtiles_to(1);
public Draw() // this is how we know which one to draw
//iterate over subtiles
for(int i..
for(int j ...)
if(subtiles[i,j] == 1)
Vector2 draw_pos = Vector2(i*tilewidth,
j*tileheight)
spritebatch.Draw(texture, draw_pos)
In a similar fashion I have a collision method that will check for collision:
public bool collides(Rectangle rect)
//iterate over subtiles
for i...
for j..
if(subtiles[i,j]==0) continue;
subtile_rect = //figure out the rect for this subtile
if(subtile_rect.intersects(rect))
return true;
return false;
And so on. You can imagine how to "destroy" certain subtiles by setting their respective value to 0, and how to check if the whole tile is destroyed.
Granted with this technique, the subtiles will all have the same texture. So far I can't think of a simpler solution.