Can I somehow get information that the player has touched a specific tile located in the resource (tilemap.res)?
It is necessary to determine which tile it stands on (for example, on land or in water)
It depends on what kind of behavior you're expecting. There's two major ways to do this:
In each individual script that you want to be affected by the tiles, get the tile it's on every time it moves, then run the logic directly from there.
As above, get the tile the unit is on each time it moves, but instead of just running the logic every time, emit a signal whenever the tile changes, and keep the current tile cached so you can check when it's on a new tile; have the TileMap itself attach to the signal, and when it receives the signal, act on the Node2D until it leaves. This is what I'd do.
The exact method to find the tile is TileMap.world_to_map(TileMap.get_cellv(Node2D.position))--you just need to have the Node2D and the TileMap, and you can get both in the same function using the above two methods.
Technically, you could also procedurally add Area2Ds to the tilemap based on the tiles at various positions using TileMap.get_used_cells_by_id, making sure that the ID is the one that has the special behavior, then attaching the TileMap to those areas' body/area_entered and body/area_exited and using that, but spamming a whole lot of Area2Ds isn't necessary when you can check the tile a Node2D is on directly.
Related
I'm working on a multiplayer horror game in Godot and I want to make it so you can't see your own body but others can. I heard about culling masks for this but I have no idea how they work and if what I'm trying to achieve is possible using them. The body is a Skeleton node and others should be able to see it but my camera (a sibling of the skeleton node) shouldn't be able to. Could someone explain how I might be able to do this?
The Skeleton is not visible. However, you must have some children VisualInstances (usually MeshInstance) which are actually visible.
In the usual setup, you have a Skeleton node, with multiple MeshInstance as children, which also have their skeleton property set to the Skeleton node.
I don't know how you are setting up your multiplayer, but if it is not split-screen you probably can swap or remove the player character but not those of the other players. If removing the Skeleton is not viable, you should still be able to remove or hide its children VisualInstances.
Anyway, if you do need to setup multiple cameras, you can se the layers on the MeshInstance (or whatever VisualInstance you are using) and the cull_mask on the Camera. If they overlap (they have common bit flags) then the Camera will render that MeshInstance, otherwise it wont.
See also Hide an object for a specific camera.
I am trying to make a basic rhythm game in Godot, but with unique controls. A few years ago, I played a cool game called Fast Like a Fox. The controls were unique, because you tapped on the back of your device to move your character to move, not on the screen. I thought the controls were cool, and I want to try to replicate them in a simple one-button rhythm game for mobile. Does anyone know if it would be possible for Godot to take that kind of input, either in a built-in function or something else?
They read the accelerometer (and maybe other sensors), which Godot supports through accelerometer, gravity and gyroscope. Accelerometers are accurate enough to read passwords as they're being typed so you can even get a rough estimate on where the user is tapping, which is used in Fast Like a Fox use case where internally they poll the sensor and raise an event when particular changes happen in one or multiple axes. In your case, it might be enough to just treat any sudden changes as an event if you simply care about the user tapping anything.
Try writing an app that will display the delta of each axis measurement then tap your phone around, you'll figure it out. Remember to test on various conditions (device being held upside down while laying on a bed, sitting on a chair, laying on one's side, etc) since different axes will register the changes.
Does a particular method get called when an SCNNode is removed from the scene?
-(void)removeFromParentNode;
Does not get called on the SCNNode object.
To set the scene
I am using gravity to pull down an object. When an object goes too far down, it automatically disappears and the draw calls and polygon counts decrease. So the SCNNode is definitely being destroyed, but is there a way I could hook into the destruction?
Other answers covered this pretty well already, but to go a bit further:
First, your node isn't being removed from the scene — its content is passing outside the camera's viewing frustum, which means SceneKit knows it doesn't need to issue draw calls to the GPU to render it. If you enumerate the child nodes of the scene (or of whatever parent contains the nodes you're talking about), you'll see that they're still there. You lose some of the rendering performance cost because SceneKit doesn't need to issue draw calls for stuff that it knows won't be visible in the frame.
(As noted in Tanguy's answer, this may be because of your zFar setting. Or it may not — it depends which direction the nodes are falling out of camera in.)
But if you keep adding nodes and letting physics drop them off the screen, you'll accumulate a pre-render performance cost, as SceneKit has to walk the scene graph every frame and figure out which nodes it'll need to issue draw calls for. This cost is pretty small for each node, but it could eventually add up to something you don't want to deal with.
And since you want to have something happen when the node falls out of frame anyway, you just need to find a good opportunity to both deal with that and clean up the disappearing node.
So where to do that? Well, you have a few options. As has been noted, you could put something into the render loop to check the visibility of every node on every frame:
- (void)renderer:(id<SCNSceneRenderer>)renderer didSimulatePhysicsAtTime:(NSTimeInterval)time {
if (![renderer isNodeInsideFrustum:myNode withPointOfView:renderer.pointOfView]) {
// it's gone, remove it from scene
}
}
But that's a somewhat expensive check to be running on every frame (remember, you're targeting 30 or 60 fps here). A better way might be to let the physics system help you:
Create a node with an SCNBox geometry that's big enough to "catch" everything that falls off the screen.
Give that node a static physics body, and set up the category and collision bit masks so that your falling nodes will collide with it.
Position that node just outside of the viewing frustum so that your falling objects hit it soon after they fall out of view.
Implement a contact delegate method to destroy the falling nodes:
- (void)physicsWorld:(SCNPhysicsWorld *)world didBeginContact:(SCNPhysicsContact *)contact {
if (/* sort out which node is which */) {
[fallingNode removeFromParentNode];
// ... and do whatever else you want to do when it falls offscreen.
}
}
Your object will disappear if it goes further than the ZFar property of your active camera. (default value is 100.0)
As said by David Rönnqvist in comments, your Node is not destroyed and you can still modify its property.
If you want to hook-up to your Node's geometry disappearance, you can calculate the distance between your active camera and your Node and check it every frame in your rendering loop to trigger an action if it gets higher than 100.
If you want to render your Node at a greater distance, you can just modify the ZFar property of your camera.
I'm looking for a simple Kinect app which allows me to a) detect and b) track a single moving object in an otherwise static background.
I don't need any fancy skeleton or other features, just the center of mass of the moving object will do it.
Any pointers?
I would see Comparing a saved movement with other movement with Kinect to track the entire body. The answer shows the code here which shows how to save skeleton data. And mapping an ellipse to a joint in kinect sdk 1.5 to have the tracking of joints if you want to track the joints not the entire body (currently works better, but when the tracking the entire body works, use that because it is more effective and efficient).
your case is pretty simple, but requires initialization for the object since in general a term "object" is ill-defined. It can be a closest object or moving object or even the object that was touched, has certain color, size or shape.
Let's assume that you define object by motion that is whatever moves in your point cloud is an object. I suggest to do this:
Object detection is easy if object moves more than its size since
then you just may subtract depth maps and end up with your object:
depth1-depth2 > T but if the object moves slowly and shifts only by a
fraction of its size you have to use whatever high frequency info you
have, which can be depth or colour or both. It is going to be noisy as the figure below shows
as soon as you have your object selected you may want to clean it by running some morphological filters (erode +
dilate) to erase noise and get a single blob. After that you just
need to find some features in the blob such as average depth or mean
color and look for them in a small window around the object's previous
location in order to rediscover the object;
finally don't forget to update these features as object moves
through.
Some other ideas you may want to use are: depth gradient, connected components in depth, pre-recording background depth for cleaner subtraction, running grabCut on depth area selected by mouse click, etc.
I have a limited area (screen) populated with a few moving objects (3-20 of them, so it's not like 10.000 :). Those objects should be moving with a constant speed and into random direction. But, there are a few limitation to it:
objects shouldn't exit the area - so if it's close to the edge, it should move away from it
objects shouldn't bump onto each other - so when one is close to another one it should move away (but not get too close to different one).
On the image below I have marked the allowed moves in this situation - for example object D shouldn't move straight up, as it would bring it to the "wall".
What I would like to have is a way to move them (one by one). Is there any simple way to achieve it, without too much calculations?
The density of objects in the area would be rather low.
There are a number of ways you might programmatically enforce your desired behavior, given that you have such a small number of objects. However, I'm going to suggest something slightly different.
What if you ran the whole thing as a physics simulation? For instance, you could set up a Box2D world with no gravity, no friction, and perfectly elastic collisions. You could model your enclosed region and populate it with objects that are proportionally larger than their on-screen counterparts so that the on-screen versions never get too close to each other (because the underlying objects in the physics simulation will collide and change direction before that can happen), and assign each object a random initial position and velocity.
Then all you have to do is step the physics simulation, and map its current state into your UI. All the tricky stuff is handled for you, and the result will probably be more believable/realistic than what you would get by trying to come up with your own movement algorithm (or if you wanted it to appear more random and less believable, you could also just periodically apply a random impulse to a random object to keep things changing unpredictably).
You can use the hitTest: method of UIView
UIView* touchedView=[self.superview hitTest:currentOrigin withEvent:nil];
In This method you have to pass the current origin of the ball and in second argument you can pass nil.
that method will return the view with which the ball is hited.
If there is any hit view you just change the direction of the ball.
for border you can set the condition for the frame of the ball if the ball go out of the boundary just change the direction of the ball.