I Have a variable that updates every time i move my cube in the level blueprint , now i want to access this variable from multiple class blueprints , what do I do , I tried casting to gamestate but didn't succeed , I am really new to ue4 if you could explain in details please
edit: sorry for not adding details ,
The var I want to access is an integer named cube_side that tells me what side the cube is on every time I move , all of this happens in the level bp , I want to access this variable to see what side the cube is on from other class blueprints ->
here are some details in a picture
I know it's not good to code everything in the level blueprint , but it's too late now , I only need to transfer the var cube_side to other class blueprints so the other object can change depending what side the cube is on.
Create an Actor Class for your logic/functionality. Then use Get all actors of class (choose your class) -> Get a copy -> get variable
Communication with the level blueprint is rather tricky in UE4, since they are not as persistent as e.g. the GameMode, and therefore shouldn't be accessed directly (Imagine older games like Final Fantasy where a new level was loaded every time you stepped outside a boundary, so relying on it could potentially break your actors or crash the game due to nullptrs).
It's a little hacky, but works:
Move the variable inside the cube-blueprint. Add an event dispatcher to the cube, if it is moved, call it and pass the variable in.
Select the cube in the editor, open the level blueprint, right-click, "add reference to selected actor" (the cube must be part of a blueprintclass, not only a static mesh dragged in, though), and bind the event dispatcher inside the Level BP.
Create a function inside every blueprint that needs access to the variable, which does whatever it should do, depending on the variable.
The custom event of the Level Bp (that was bound to the Event Dispatcher of the cube), needs references to all actors that have to work, when the variable changes and call each Actors function (you can get the references like you got the one from the cube)
Then, every time the variable changes, the Level BP is notified, the custom Event is executed and this custom event calls all the actor's functions.
Event Dispatchers explained
This is a huge wastage of functions/code, since you only need it for this one level and may never use it again. Avoid this in the future, by not relying on the level BP so much.
You can use GameStateBP to create and store all variables that you need in game, in GameModeBP create functions to get and set this variables via Get Game State function and then function Cast To GameState and then logic. After that from any blueprint access it using Get Game Mode -> Cast to you GameMode -> use your function to set or get data from GameState.
Related
I have made an blueprint and inside of it, variable of type StaticMeshActor (object reference):
When I create instance of this blueprint in scene, I get the drop-down for my “Test” variable with StaticMeshActor actors in scene (that’s correct).
But once I click on any of them (that are from sub-levels), field resets to “None” again. Same goes for picker icon from scene.
Is it bug, or am I doing something wrong? Is it even possible to select actor from sub-level?
I'm attempting to dynamically add Manipulation Events to a ManipulationHandler that is being added to child objects of a parent. The parent object will be what the user is inspecting, but the user will be able to grab parts off of the parent and inspect them more closely. (i.e. you can look at an engine (parent object), but if you want to inspect the pistons (child objects) you can grab them and look at them)
Instead of having to go into every child object and manually add it in Unity I'd like to be able to add the parent object and just procedurally add the ManipulationHandler and ManipulationEvents on start or awake.
So far I have the following code for adding the ManipulationHandler script, but to add the ManipulationEvent I'm not sure how to set up the pointers so I can use the script and function I want from the source:
gameObject.AddComponent<ManipulationHandler>();
ManipulationHandler handler = gameObject.GetComponent<ManipulationHandler>();
ManipulationEvent newevent = new ManipulationEvent();
ManipulationEventData eventdata = new ManipulationEventData();
eventdata.ManipulationSource = gameObject;
The program works when I grab the objects, but I'd like to add manipulation events when I grab them so I can display additional data.
I see there's a getter and setter for Pointer in ManipulationEventData, but I'm not sure how to instantiate IMixedRealityPointer and how to get it to work. I'm also not sure if that's the object I actually need to accomplish what I'd like to accomplish.
I apologize in advance if I've missed something obvious. I'm new to MRTK.
Thanks!
The ManipulationHandler has four callback events among them OnManipulationStarted and OnManipulationEnded you can simply add listeners to. (see UnityEvent.AddListener)
Unless I understood your question wrong you don't have to instantiate any IMixedRealityPointer. You don't create the event data yourself but rather the ManipulationHandler feeds these events with the current event data including the interacting pointer information. The ManipulationHandler uses OnPointerDown and OnPointerDragged and OnPointerUp via the IMixedRealityPointerHandler interface in order to manage the interacting pointers and invokes the according events where needed.
Instead of using AddComponent followed by GetComponent directly store and use the return value of AddComponent which will be the reference of the newly added Component. MRTK also has an extension method
T EnsureComponent<T>(this Component component) where T : Component
so that you can simply use e.g.
var handler = this.EnsureComponent<ManipulationHandler>();
which internally first checks whether the component already exists, and if not it adds it.
Note that in order to enable near interactions you will also need a NearInteractionGrabbable so you should add this one too.
You also will have to make sure that your objects have some sort of Collider attached to the same GameObject as the NearInteractionGrabbable.
...
gameObject.transform.EnsureComponnet<NearInteractionGrabbable>();
var handler = gameObject.transform.EnsureComponnet<ManipulationHandler>();
handler.OnManipulationStarted.AddListener(HandleOnManipulationStarted);
handler.OnManipulationEnded.AddListener(HandleOnManipulationEnded);
...
/// <summary>
/// If you need it later you need to store the pointer since unfortunately in
/// OnManipulationEnded the <see cref="ManipulationEventData.Pointer"/> is null
/// (no idea why they do it this way :D )
/// </summary>
private IMixedRealityPointer _pointer;
private void HandleOnManipulationStarted(ManipulationEventData eventData)
{
_pointer = eventData.Pointer;
// whatever shall happen when manipulation started
}
private void HandleOnManipulationEnded(ManipulationEventData eventData)
{
// whatever shall happen when manipulation ended
}
Note: I am not sure if this thing you are trying to achieve is possible with this architecture ... it is very possible that nesting various ManipulationHanlder leads to strange behavior here and there. Especially very small parts will be almost impossible to grab ...
I want to add an object reference to an array in unreal blueprints, but I don't want to spawn it in the level. Is this even possible?
I tried setting the collision override to 'Do not spawn'. But it still does...
Here is the code: https://blueprintue.com/render/dvdrvdws
I expected that the actor doesn't spawn, but the actual result is that it spawns.
This is wrong add the weapon class in the array(turn the array type to weapon) , now only spawn what you want and when you want from this array using a different function or as you see fit .
When I designed one Slot properties in blueprint, it works just when I put it on another blueprint directly.when I dynamic create one and addchild to another widget use C++, Slot properties designed in blueprint are not works, I need to set it by code, like this:
this->Slot:SetMinimum(FVector2D.ZeroVector);
this->Slot:SetMaximum(FVector2D.UnitVector);
this->Slot:SetPosition(FVector2D.ZeroVector);
this->Slot:SetSize(FVector2D.ZeroVector);
I am trying to construct a workflow that can be assigned to arbitrary containers and will have the following behavior. When the container makes the transition from state A -> A', the contents of the container should be checked for their state and moved to a new state that depends on their present state. In other words:
obj1: in state 'a' would be transitioned to 'a*'
obj2: in state 'b' would be transitioned to 'b*'
and so on...
obj1 and obj2 are following the same workflow that branches to a number of final states (approved, denied, alternate, etc...)
I know how to do this, if I can trigger my python code as trusted code. Unfortunately, I have not been able to figure out how or where to put the code in my product so this will work. I have found references to using "external methods", however that seems to be going away. Also I want the code to reside in my project.
I think this is probably simple and I am overlooking something. Help with how to put this in my project or another route to achieving the same goal would be welcome.
The scripts support for DCWorkflow only supports through-the-web-addable objects, which limits you to External Methods there.
A better bet is to use workflow events instead. For each workflow transition, two events are fired:
Products.DCWorkflow.interfaces.IAfterTransitionEvent
Products.DCWorkflow.interfaces.IBeforeTransitionEvent
If you subscribe to either of those events, you can then filter on the correct workflow and transistion to react to transitions from trusted code.
Each event fired has the following attributes:
object: the workflowed object
workflow: the current applicable workflow object
old_state: a Products.DCWorkflow.States.StateDefinition object
new_state: another Products.DCWorkflow.States.StateDefinition object
transition: a Products.DCWorkflow.Transititions.TransitionDefinition object
status: a dictionary with the current workflow variables
kwargs: a dictionary of extra arguments passed in to the change-transition call.
Register a subscriber using ZCML:
<subscriber
provides="zope.component.testfiles.adapter.IS"
factory=".youreventsmodule.aftertransition_handler"
for="Products.DCWorkflow.interfaces.IAfterTransitionEvent"
/>
or, because the transition events are object events, listen only to the transition event if it applies to your objects:
<subscriber
provides="zope.component.testfiles.adapter.IS"
factory=".youreventsmodule.container_aftertransition_handler"
for=".interfaces.IMyContainerType
Products.DCWorkflow.interfaces.IAfterTransitionEvent"
/>
which registers your handler only for transition events on objects with the IMyContainerType interface only.
The handler would be:
def aftertransition_handler(event):
# handle all transition events, ever
or, when limiting it to one object interface:
def aftertransition_handler(obj, event):
# handle all transition events for our container interface