I am developing an AR application using Babylon.js. I need to hide a virtual object behind a real object using a transparent mesh, like is described on this question regarding Three.js: three.js transparent object occlusion
Is it possible to do something like this with Babylon.js, I haven't been able to figure it out?
Sure, you can use a mesh to occlude parts of another mesh, you only have to turn off and turn on the mesh (occluder) before and after rendering.
occluderMesh.onBeforeRenderObservable.add(() => engine.setColorWrite(false));
occluderMesh.onAfterRenderObservable.add(() => engine.setColorWrite(true));
Check this example: https://playground.babylonjs.com/#AAM6LK
Related
I would like to add 3D object in Windows 10 UWP map control.
This object would be "polygon with height", e.g. simple representation of a house - cuboid or cube.
Illustration image:
I know that I can add Xaml control (and inside it 3D object e.g. Cube) but then this Cube is not 'map object', only pinned to a certain Lat/Lon.
Any idea how to implement this?
Microsoft has added MapElement3D in Windows 10 Insider Preview v10.0.16257.0. - that's the falls creators update. It allows you to add objects, turn them, control their size, and direction. You can make them move too!
Example
How-To
Represents a 3D element displayed on a MapControl.
It's usage appears to be very similar to other MapElements, such as MapIcons and MapBillboards.
map3dSphereStreamReference = RandomAccessStreamReference.CreateFromUri
(new Uri("ms-appx:///Assets/trainengine.3mf"));
var myModel = await MapModel3D.CreateFrom3MFAsync(map3dSphereStreamReference,
MapModel3DShadingOption.Smooth);
var my3DElement = new MapElement3D();
my3DElement.Location = myMap.Center;
my3DElement.Model = myModel;
myMap.MapElements.Add(my3DElement);
Beware of two undocumented issues:
Attempting to add the same 3DMapElement to two different MapControls will result in System.AccessViolationException. This can happen if you cached the 3D model but not the page with the map control.
HResult=-2147467261 Message=Attempted to read or write protected
memory. This is often an indication that other memory is corrupt.
Attempting to call MapModel3D.CreateFrom3MFAsync() from a non-Ui thread will cause a crash. This must be called from a UI thread.
I don't know how to get sprites to stick to each other so they become one big object instead of tiny little pieces, for example:
attaching a thruster to a box, then the thruster stays in that spot while pushing the box, and also is there a certain term for what I'm talking about?
You could also attach all parts to one of the objects, it would sort of look like:
//Main object
x = 5;
y = 20;
//other object step event
x = obj_main.x + <any value to put it where you want>;
y = obj_main.y + <any value to put it where you want>;
//This will force the parts to follow the main object.
`
`
You can use an array, defined in the 'main' object to use a sort of grid to define where each piece is and then either draw each individual sprite, based on its position in the array, originating from the 'main' object's coordinates. Or just create an individual instance of an object if you would like to have additional functionality by trading off some performance.
For more information on arrays and how to position sprites and objects based on set coordinates, check out the GML documentation provided below:
Arrays:
https://docs.yoyogames.com/source/dadiospice/002_reference/001_gml%20language%20overview/401_06_arrays.html
lengthdir:
https://docs.yoyogames.com/source/dadiospice/002_reference/maths/real%20valued%20functions/lengthdir_x.html
what I did was make the object disabled, so when I press left and right it doesn't go anywhere, only the other piece would move, but when it came into contact it allowed the other piece to move along with it, and set its speed to the corresponding objects speed, in simpler term, when I collide with it, it turns the movement on and goes in the same direction as the current object in the same speed, making it look like its sticking
I'd like to know if there's a way to check if an object exists on a point, and if not, create a new one while snapping the new object to a grid? I know you can use this instance_create(x,y,obj_to_create); but that just places on a point no matter what and doesn't snap to a grid. Also, is there a global mouse click event in Game Maker?
Thanks!
well there are a few (almost similar) functions that allow you to do this... But most straight forward is to use position_meeting(x,y, obj)
so the could would become:
if (!position_meeting(x, y, obj_to_create)) {
instance_create(x,y,obj_to_create);
}
Now to snap to grid you'll have to create it at a snapped position:
instance_create(x div GRIDW, y div GRIDH, obj_to_create);
I'm trying to figure out the best way to initialize multiple sprites placed in Tiled that are the same type. I don't even know really how to start off in Tiled, because I'm only used to initializing one sprite by filling out the name field, and then in my CCLayer with the map I do something like
CCTMXObjectGroup *objects = [theMap objectGroupNamed:#"oj"];
NSMutableDictionary *startPoint = [objects objectNamed:#"StartPoint"];
int x = [[startPoint valueForKey:#"x"] intValue];
int y = [[startPoint valueForKey:#"y"] intValue];
hero = [[HeroClass alloc] init];
[self addChild:hero.heroSpriteSheet];
hero.heroSprite.position = ccp(x,y);
As you can see, my "hero" is subclassed, and this goes for another sprite that is a bird, but I want an x amount of them. I import the header of HeroClass and create a pointer, make a property and synthesize that in my main file and finally release HeroClass in dealloc. I have a feeling that I will most likely end up use NSMutableArray, but I don't really know how in the case of subclassing. Also I'm not sure if I'll be using objectNamed:#"name" because I'll have x number of these sprites that I will be just duplicating throughout Tiled.
There's a helpful post here that shows how to add multiple sprites, but I don't know how to relate it to Tiled or subclassing:
http://www.iphonedevsdk.com/forum/iphone-sdk-game-development/58334-adding-sprites-screen-when-detecting-tap-cocos2d.html
Does anyone have any useful pointers or code examples relating how to resolve my issue? Thanks!
TLDR:
How do I initialize sprites from the same class in a CCLayer (that renders my map and other sprites) based upon definite object locations that were placed in a Tiled TMX map?
I'd suggesting creating an enemy class. Then, you create a bunch of them using a for loop. As far as spawnpoints, you would have each enemy set its own spawn point up based on rules. (Map borders, "safe areas", etc.)
I am building a graphic board like project where i am facing a design issue.
Main Class is Board which is a canvas responsible for handling mouse events when drawing shapes. It also has context variables such as currentShape or snapFlag to activate grid magnetism.
To handle the moving / resizing / rotating of the shapes, they inherit from a third party open source tool called ObjectHandles (flex).
I have a baseShape extending ObjectHandles main class to override some of its internal functions, like the onMove function.
When creating a shape (mouse down, move, mouse up) this is handle by the Board and it knows about his own snap flag.
var mouseUpPoint:Point = boardCanvas.globalToLocal(new Point(event.stageX, event.stageY));
var snapMouseUpPoint = snapPoint(mouseUpPoint.x, mouseUpPoint.y);
In my overidden onMove method i would like the shape to be aware of the Board snap flag and when its changing. How do i do this ?
Do i pass the Board as a parameter in my basicShape constructor so that i can check snap ?
Do i pass the flag as a parameter and somehow make all shapes listen for change ?
What is the cleanest solution ?
Thanks a lot.
I would approach this from a slightly different angle. I assume that the Board object traps mouse events first, so that it can decide which shape has been clicked on. I would have the board trap mouse movements as well, passing the correct (snapped or unsnapped) coordinates "down" to the selected Shape object, rather than letting the shape object figure it out.
This leaves the grid snap handling to the Board, and keeps your Shape object onMove method free of clutter.
Not knowing your app:
Is it ever possible for a Shape to have it's own 'snap' behavior? That is, could a Shape be excluded from snapping while others aren't? If so, make snapFlag a member of Shape. When snapFlag is set on the Board, iterate through your Shapes and set or don't set according to your rules.
If snapping behavior applies to all Shapes on the Board, consider an event-driven model (if it's available - I'm a Flex noob). When a Shape moves, have it raise an OnMove event. The Board can then respond and decide to 'snap' the Shape into place if it's appropriate.
If snap behavior applies to all Shapes and events aren't available, I'd just say the hell with loose coupling in this case - make the Shapes Board-aware. It sounds like you're saving a bunch of code by using the ObjectHandle. That benefit may out-weigh the cost of coupling your UI elements.
Just trying to think together with you..
I see no big deal in Shapes having IBoard interface.
Though, I don't like the idea that they have to check the flag on the board...
How would you pass the flag as parameter? In OnMove() method? didn't understood this quite well...could you expand?
Though..
If you try to think a bit about SRP - single responsibility principle...what is the responsibility of Shape classes?
Yea, this is what eJames wrote already.
It feels to me that their main responsibility is probably NOT handling mouse events...here need to know more about your application, but my general feeling is why not someone else get this mouse down and then figure out what the shape should do with it and for instance call Draw() on the Shape with new coordinates?
Let's say you want to apply something like Composite pattern (Shapes inside shapes...) and you want them to be able to handle those mouse events themselves...but then
Then it would be logical if they perceived this mouse event in their local coordinates, but then I think you should provide all the information through this event (local coordinates, mouse status...) so that they don't have to ask for "global" variables on the board...
Passing the flag as a parameter for the shape constructor. But it wont be good since flag is going to change and i have to make each shape to update their flag copy on change.
Its true that shape responsibility is not to know how to handle mouse events. But thats what ObjectHandles do: react to events, update height width rotation parameter of the shape.
Maybe i should transfer some of the library code in my board class to handle shape selection and movement / resizing / rotation.
OnMouseMove ObjectHandles
protected function onMouseMove(event:MouseEvent) : void
{
if( ! visible ) { return; }
if( ! event.buttonDown )
{
setMouseCursor( event.stageX, event.stageY );
return;
}
if(parent == null )
{
return;
}
var dest:Point = parent.globalToLocal( new Point(event.stageX, event.stageY) );
var desiredPos:Point = new Point();
var desiredSize:Point = new Point();
var desiredRotation:Number = 0;
... plenty more
then
if( wasMoved ) { dispatchMoving() ; }
if( wasResized ) { dispatchResizing() ; }
if( wasRotated ) { dispatchRotating(); }
So i can not listen for move event and tell the board to snap it since the shape is already moving freely. I should add snap here:
var dest:Point = parent.globalToLocal( new Point(event.stageX, event.stageY) );
All shapes follow the snap rule there can not be one snapping and the other free.
Solved it this way:
Since i overridde onMouseMove in my baseShape class and i am using PureMVC framework, i just made baseShape aware of my boardMediator.
override protected function onMouseMove(event:MouseEvent) : void
{
[...]
// added on override
var board:BoardMediator = ApplicationFacade.getInstance().retrieveMediator(BoardMediator.NAME) as BoardMediator;
Then
desiredPos = board.snapPoint(desiredPos.x, desiredPos.y);
Maybe not super pretty but it works, o
Overridding the globalToLocal method in my board view did work too but some more calculations were done inside onMouseMove resulting in an out of alignment snap move.
Use ObjectHandles Version 2, and then create a constraint to do what you want.