I am experimenting with Apple's GameplayKit, SpriteKit and Swift. I am trying to wrap my head around pathfinding through tiles which are passable from only one side.
The diagram below shows two problems:
On the left is a simple solution, I understand how to move from the green position to the red position as all I need to do is remove the wall nodes (the black outlined squares) from the graph and compute the path.
The right hand side of the diagram is puzzling me. Say I want to have tiles which have a wall along their left hand side (as illustrated in the diagram) but I still want to be able to navigate to a tile with a wall. How do I go about telling the graph that those tiles with walls on the left-hand side of the tile are only passable if approached from the top, bottom or right side and not the left?
In response to Alessandro's comment I will explain about the structure of the code. I'm using the new TileMapNode introduced to SpriteKit in iOS 10 to represent the tile map. Each tile is a SKTileDefinition. Custom properties can be set on SKTileDefinition (for instance I could set an Int to represent if there is a wall on the top, bottom, left or right of the tile). The actual representation of the map is less important than how you path find with GameplayKit. As far as I can see, GameplayKit only allows you to remove nodes from the graph that are impassable but what I want to do I mark some nodes as passable but only from a particular direction.
This strikes me as a common problem (as lots of games don't have to sacrifice an entire tile to represent an internal wall) but I don't have the faintest idea how to go about it.
You have a couple options:
1) Decrease your grid size. The presence of thin walls suggests your grid size could be smaller (on the order of the smallest obstacles)
2) Use a different graph type and abandon the grid altogether. GKObstacleGraph or GKMeshGraph are well suited to a game world that has a number of arbitrary polygonal obstacles.
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I'm new to Unity and to game development in general.
I would like to make a text-based game.
I'm looking to reproduce the behavior of an instant messenger like messenger or whatapp.
I made the choice to use the Unity UI system for the pre-made components like the rect scroll.
But this choice led me to the following problem:
I have "bubbles" of dialogs, which must be able to grow in width as well as in height with the size of the text. Fig.1
I immediately tried to use VectorGraphics to import .svg with the idea to move runtime the points of my curves of Beziers.
But I did not find how to access these points and edit them runtime.
I then found the "Sprite shapes" but they are not part of the "UI",
so if I went with such a solution, I would have to reimplement
scroll, buttons etc...
I thought of cutting my speech bubble in 7 parts Fig.2 and scaling it according to the text size. But I have the feeling that this is very heavy for not much.
Finally I wonder if a hybrid solution would not be the best, use the
UI for scrolling, get transforms and inject them into Shape sprites
(outside the Canvas).
If it is possible to do 1. and then I would be very grateful for an example.
If not 2. 3. 4. seem feasible, I would like to have your opinion on the most relevant of the 3.
Thanks in advance.
There is a simpler and quite elegant solution to your problem that uses nothing but the sprite itself (or rather the design of the sprite).
Take a look at 9-slicing Sprites from the official unity documentation.
With the Sprite Editor you can create borders around the "core" of your speech bubble. Since these speech bubbles are usually colored in a single color and contain nothing else, the ImageType: Sliced would be the perfect solution for what you have in mind. I've created a small Example Sprite to explain in more detail how to approach this:
The sprite itself is 512 pixels wide and 512 pixels high. Each of the cubes missing from the edges is 8x8 pixels, so the top, bottom, and left borders are 3x8=24 pixels deep. The right side has an extra 16 pixels of space to represent a small "tail" on the bubble (bottom right corner). So, we have 4 borders: top=24, bottom=24, left=24 and right=40 pixels. After importing such a sprite, we just have to set its MeshType to FullRect, click Apply and set the 4 borders using the Sprite Editor (don't forget to Apply them too). The last thing to do is to use the sprite in an Image Component on the Canvas and set the ImageType of this Component to Sliced. Now you can scale/warp the Image as much as you like - the border will always keep its original size without deforming. And since your bubble has a solid "core", the Sliced option will stretch this core unnoticed.
Edit: When scaling the Image you must use its Width and Height instead of the (1,1,1)-based Scale, because the Scale might still distort your Image. Also, here is another screenshot showing the results in different sizes.
I'm trying to add a black outline surrounding a sprite I have for a tank.
I've tried following every tutorial I could find on 2d outlines for sprites, however almost all of them were done using a previous unity version (I'm using 2021.1.3f1) and don't seem to have any of the problems I've been having.
After using Alpha subtraction on an offset copy of the sample texture (and multiplying by a color) I then try to add it back to the original sample texture. That's when things go wrong, no matter what I've tried it keeps either chopping off the right side of the sprite (I was trying to add the left outline first), or making the right side of the sprite the opposite color of what I'm putting on the left.
What I mean by "cutting off the right", those treads should be the same thickness on the right as on the left, it's like adding the outline to one side trimmed the other.
If it matters, the sprite is a PNG I got from Kenney and then modified in Krita.
For whatever reason, changing the color of the outline seems to also change how much is getting trimmed.
I've been banging my head against this for four hours now, any ideas or suggestions are greatly appreciated.
Update: After following One Full Time Equivalent's suggestion below I do get an outline surrounding the entire sprite, but now it's distorting the colors at the edges of the sprite as seen here:
After replacing Add with Blend
After your subtraction node, put in an Absolute node, otherwise you will subtract the right edge in the alpha channel (this is exactly what you observe right now). Always be aware that you can only see half the color space and negative channels can be tricky to deal with.
I need to move an image down through canvas so that its central point would be where is now its top edge. It makes some 50 points, but if I decrease y by 50, it moves to different part of the screen on devices with different screen size. I guess, it's because my main canvas is set to scale with the screen size. So I suppose I need to manually divide the number 50 by my screen height and then code to multiply by Screen.height? Isn't there a more convenient way to move UI objects?
Allow me a second question: Do you think it is even wise to make a game purely on canvas? My game is simple 2D, only slightly animated and contains many layout elements, so I decided to go for it, but I have hard time to grasp the UI position rules.
you may have the problem of the anchoring.
Unity UI totally depends on the Anchoring, if you have got right anchoring there is no issue.
For example. if you anchored something at the Center than changing left and right value moves them according to the center anchor.
for clear visualization, you can paste a screenshot of the behavior.
I am trying to draw a box that can help someone understand the dimensions of an item, but I keep having the issue that since I first need to recognize a plane when I put my physical item on top of the plane, my box gets drawn in front of the item.
Is it possible to somehow overcome this?
#John Scalo is right, your problem is not having to first detect a plane, but it's that your render engine doesn't know that part of your green box frame is occluded (hidden) by a real-world object.
"…to somehow overcome this"
Yes, and by doing so you might be "solving" your original problem—help someone understand the dimensions of an item.
(Depending on your choice of render engine, e.g. SceneKit) You can add an invisible 3D object that has the same dimensions as the real-world object; so the render engine will "know" that some parts of your box frame are behind this (for the user invisible) 3D object. Therefor, you can tell it not to draw those parts of your box frame, which will give the illusion (borrowing from Apple here) that your soda can has the box around it.
These workarounds are inaccurate, but maybe their accuracy is enough for the level of realism you are trying to achieve:
Option 1: 1. After detecting the desk surface, place a semi-transparent 3D object over the soda can and then resize it (gestures/buttons your choice) until it's about the dimensions of the soda can. 2. Confirm that you're done, and just don't draw a texture on it at all just let it occlude the green box frame.
Option 2: Hold your device near the edges of the soda can and add "enough" ARAnchors to be able to create a "bounding shape" that (again) can be used to capture the real-word object and occlude that.
Option 3: (intense, and perhaps the least accurate) Use your finger to "brush" over the object from various angles, and on each touch perform a hit test (hopefully the top/nearest hit is a part of your soda can) and build up a "bounding shape" that way.
Option X: any combination of 1 - 2 - 3.
Good luck, there's lots of people trying to work around this device/ARKit limitation at them moment, so keep your eyes open for good ideas.
The problem you're dealing with is called occlusion, and ARKit doesn't (currently?) include occlusion support. Maybe some day soon iPhones and iPads will begin to ship with LIDAR (or similar), in which case ARKit will be able to detect objects in the scene, making occlusion much easier.
I am working on a iOS 5 iPhone project where users can choose an image on their device, then trace an object inside of the picture (trace an apple out of a picture of a fruit basket), and then the picture needs to be uploaded with the "tagged" object so it can be pulled down later. Other people will then pull down the image and try to find where the tagged object is in the picture (Think "Where's Waldo?").
I have been trying to figure out the best way of tracing the object. Before, I had a user press the top left, top right, bottom left, and bottom right points around the object and create a square view around the object. The info for that view was uploaded and then pulled down for the user to find the object. The downside is that all objects are obviously not squares/rectangles so I need to do a free form shape.
I was thinking of allowing the user to draw over the object and then somehow I need to be able to tell what is inside of the trace (For example, inside of a circle that they traced), but a problem I forsee is making sure the trace they made is closed so I can fill in the shape (which is a whole not problem).
Any advice welcome on the best way of starting this.
Thanks!
UIBezierPath might be a very useful friend here. It allows you to create any shape you need, and it supports both drawing and hit-detection. I recently did an implementation for a storybook where I could trace out a shape with their finger, freeze it, and then use the shape for tap detection.
The basic idea is this:
When your finger touches the screen, start recording positions. Discard any positions that are too close to the previous position (eg, only record a point if it is >min-distance from the last recorded point). While doing this, you can draw the UIBezierPath so you can see what you are tracing out. Modify the UIBezierPath by adding points to it, instead of recreating it every time.* When you lift your finger, close the bezier path. Quite simple.
Now, this will result in a polygon (ie, straight edges). If your min-distance is low enough or if you are using it for hit-detection (as you say), it won't really matter. However, if you want to smooth the path, you have to use the curve-to methods, which slightly complicate it - but should you wish to follow up on this more, read up on splines and spline generation from a point series.
*note: otherwise you'll get lag while drawing large shapes because recreating a bezier path from an increasingly large series of points gets expensive. Modifying the existing path makes it much, much, much faster.