Is it possible to use object picking through Viewports

a-nameless-ghoul

I've created a setup to render my pixel art game at a low resolution while having the UI rendered at a high resolution. The scene tree for that looks like this: I'm passing the gui_input event from the SceneTexture Node to the SceneViewport

Other gui events for buttons etc. are working correctly but, even though object picking is enabled on both of the viewports, collision objects in the scene do not get their input_event signals triggered.

I tried to recreate a minimal project as an example. I used the 3D Viewport Scaling Demo. I added an Area node with a script to print when left click is pressed on the object through the input_event signal. Playing the 3D scene on its own the signal works, but in the main scene with the viewport it does not.

# cubeArea.gd
extends Area


func _on_Area_input_event(camera, event, position, normal, shape_idx):
	if event is InputEventMouseButton:
		if event.is_pressed() and event.button_index == BUTTON_LEFT:
			print("Object Picked!")

RichNaoo

Do you have a control node that spans the entire viewport in the UICanvas? If yes try setting the mouse filter mode to ignore. Control nodes (and derivatives) will capture from front to back in the viewport.

If there's a ControlNode1 above another ControlNode2 the mouse input event is captured by ControlNode1, depending on how you set the mouse filter mode it will: a. stop the event b. pass it on to the parent node c. ignore the event and let it get captured by any Control nodes underneath it

cybereality

You have to pass the input through the viewport (by default it is captured).

func _input(event):
	if viewport and is_inside_tree():
		viewport.input(event)
		
func _unhandled_input(event):
	if viewport and is_inside_tree():
		viewport.unhandled_input(event)

That script can be on your root node, which will pass the input to your game, which is inside viewport.