connecting sound with collisions on flipping objects?

ondesic

I have a rigidbody node with a cube shape collision. It will be a dice. when I roll the dice it will hit different sides and edges until it stops flat. Like a normal dice, I want to have a sound play with each contact. It seems that most collision detection only occurs once on contact. The dice is always in contact with the table. How would I detect each edge and side hitting the tale to simulate the sound?

Megalomaniak

Give each corner of the dice it's own little collision sphere?

dotted

Look into

RigidBody._integrate_forces(state:PhysicsDirectBodyState)

and

PhysicsDirectBodyState

If you turn on contact monitoring and set reported contacts > 0, the location of a contact should change as the body interacts a table.

Alternately, you can also access PhysicsDirectSpaceState and use collide_shape()

just notice that the returned array returns contact point and normal pairs. The doc are inaccurate, there

ondesic

Could you be so kind to give a quick code example of how to access the PhysicsDirectSpaceState? Let's say the rigidbody is called "Dice". How would I use PhysicsDirectSpaceState to find the points it is contacting another object?

TwistedTwigleg

While its for raycasting, this page on the documentation explains how to access the PhysicsDirectSpaceState for 2D and 3D.

This function is the one needed for colliding shapes. The thing I'm unsure on is how to setup/get the PhysicsShapeQueryParameters. I think you can use the set_shape function though to get it setup semi-automatically, so if your RigidBody node only has a single CollisionShape this is probably the way to go. Something like this may work:

extends RigidBody

# Other code, initialization, etc

func _physics_process(delta):
	var space_state = get_world().direct_space_state
	
	var shape_query = PhysicsShapeQueryParameters.new()
	shape_query.set_shape(get_node("CollisionShape").shape)
	shape_query.transform = GlobalTransform
	
	var collision_info = space_state.collide_shape(shape_query)
	for collision_hit in collision_info:
		# Print the position and normal of each collision
		print ("Position: ", collision_hit["position"], " | Normal: ", collision_hit["normal"])

ondesic

Thanks for the idea. The hardest thing I have run into is that, even though the dice looks like it only collides a few times, in reality it is colliding hundreds of times in a few seconds with the table. I can't connect a sound to each collision because it sounds awful. How do I get collisions that match more with what the user sees? That way, the dice sounds real and not like a machine gun.

dotted

Regarding PhysicsQuery: It's not too crazy as @TwistedTwigleg has mentioned.

You give it a collision-shape, or a object containing one like and area or physics-body (through set_shape), the transform is set from shape containers like areas/bodies (iirc). Set mask, and collisions in a similar way to physics-bodies.

You can think of it as presenting much of the same parameters as you set on a physics-body and direct state is running 'simulations' of collisions of that body.

Regarding collision activity

Use a hash (dictionary) of object-ids to detect onset and expiration of a contact between your die and its surroundings.

In this case you can simply use collision monitoring and read the set of contact objects and feed that into your hash/test with:

Filter sfx cues by: if the hash has an colliding-id, do nothing, if it does not, add the id to the hash, and cue sound.

Track existing contacts by: build a fresh hash from the existing collisions and save that for the next processing loop.

so when building the new hash, use the existing one to detect if you should cue sfx. replace the existing hash with the one you are building up to maintain a list of existing contacts from physics processing calls