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Add OMI_physics_gravity implementation and test files
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aaronfranke committed Apr 5, 2024
1 parent 8b186ab commit 3636bfa
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Showing 39 changed files with 2,767 additions and 4 deletions.
4 changes: 4 additions & 0 deletions .prettierrc.json
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{
"printWidth": 120,
"tabWidth": 4
}
2 changes: 2 additions & 0 deletions addons/omi_extensions/omi_extensions_plugin.gd
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Expand Up @@ -9,5 +9,7 @@ func _enter_tree() -> void:
GLTFDocument.register_gltf_document_extension(ext)
ext = GLTFDocumentExtensionOMISpawnPoint.new()
GLTFDocument.register_gltf_document_extension(ext)
ext = GLTFDocumentExtensionOMIPhysicsGravity.new()
GLTFDocument.register_gltf_document_extension(ext, true)
ext = GLTFDocumentExtensionOMIPhysicsJoint.new()
GLTFDocument.register_gltf_document_extension(ext)
312 changes: 312 additions & 0 deletions addons/omi_extensions/physics_gravity/custom_gravity_area.gd
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@tool
class_name CustomGravityArea3D
extends Area3D


enum CustomGravityType {
DIRECTIONAL, ## Gravity in a direction in local space.
POINT, ## Gravity towards the local origin point.
DISC, ## Gravity towards a filled circle on the local XZ plane.
TORUS, ## Gravity towards a hollow circle on the local XZ plane.
LINE, ## Gravity towards a line defined by points in local space.
SHAPED, ## Gravity towards a shape in local space.
}

@export var custom_gravity_type: CustomGravityType:
set(value):
custom_gravity_type = value
notify_property_list_changed()

var direction := Vector3.DOWN
var radius: float = 1.0
var line_points: PackedVector3Array
var shape: Shape3D


func _ready() -> void:
if gravity_space_override == SPACE_OVERRIDE_DISABLED:
push_warning("CustomGravityArea3D has its Area3D gravity override disabled, this node will not have gravity.")
if gravity_type != GRAVITY_TYPE_TARGET:
push_warning("CustomGravityArea3D has its Area3D gravity type not set to target. The CustomGravityArea3D gravity logic will not be used.")


func _calculate_gravity_target(local_position: Vector3) -> Vector3:
match custom_gravity_type:
CustomGravityType.DIRECTIONAL:
return local_position + direction
CustomGravityType.POINT:
return Vector3.ZERO
CustomGravityType.DISC:
var flat_position = Vector3(local_position.x, 0.0, local_position.z)
return flat_position.limit_length(radius)
CustomGravityType.TORUS:
var flat_position = Vector3(local_position.x, 0.0, local_position.z)
return flat_position.normalized() * radius
CustomGravityType.LINE:
var closest_point := Vector3.ZERO
var closest_distance_sq: float = INF
for i in range(line_points.size() - 1):
var a: Vector3 = line_points[i]
var b: Vector3 = line_points[i + 1]
var closest: Vector3 = Geometry3D.get_closest_point_to_segment(local_position, a, b)
var distance_sq: float = local_position.distance_squared_to(closest)
if distance_sq < closest_distance_sq:
closest_point = closest
closest_distance_sq = distance_sq
return closest_point
CustomGravityType.SHAPED:
return _get_closest_point_on_shape(shape, local_position)
return Vector3()


static func _project_point_onto_triangle(point: Vector3, a: Vector3, b: Vector3, c: Vector3) -> Vector3:
var plane: Plane = Plane(a, b, c)
var projected: Vector3 = plane.project(point)
var bary: Vector3 = Geometry3D.get_triangle_barycentric_coords(projected, a, b, c)
if 0.0 < bary.x and bary.x < 1.0 and 0.0 < bary.y and bary.y < 1.0 and 0.0 < bary.z and bary.z < 1.0:
return projected # If all barycentric coordinates are between 0 and 1, this is on the triangle.
# Else, find which two barycentric coordinates are the greatest, and project onto that line segment.
if bary.x < bary.y and bary.x < bary.z:
return Geometry3D.get_closest_point_to_segment(projected, b, c)
if bary.y < bary.x and bary.y < bary.z:
return Geometry3D.get_closest_point_to_segment(projected, a, c)
return Geometry3D.get_closest_point_to_segment(projected, a, b)


static func _get_closest_point_on_shape(shape: Shape3D, point: Vector3) -> Vector3:
if shape is BoxShape3D:
var extents = shape.size * 0.5
return point.clamp(-extents, extents)
if shape is SphereShape3D:
return point.limit_length(shape.radius)
if shape is CapsuleShape3D:
var mid_extent: float = (shape.height - shape.radius * 2.0) * 0.5
var projected: Vector3 = Geometry3D.get_closest_point_to_segment(point, Vector3(0.0, -mid_extent, 0.0), Vector3(0.0, mid_extent, 0.0))
var difference: Vector3 = (point - projected).limit_length(shape.radius)
return projected + difference
if shape is CylinderShape3D:
var extent: float = shape.height * 0.5
var projected: Vector3 = Geometry3D.get_closest_point_to_segment(point, Vector3(0.0, -extent, 0.0), Vector3(0.0, extent, 0.0))
var flat_location = Vector3(point.x, 0.0, point.z)
return projected + flat_location.limit_length(shape.radius)
if shape is ConcavePolygonShape3D:
var closest_point := Vector3.ZERO
var closest_distance_sq: float = INF
var faces: PackedVector3Array = shape.get_faces()
for i in range(0, faces.size(), 3):
var on_triangle: Vector3 = _project_point_onto_triangle(point, faces[i], faces[i + 1], faces[i + 2])
var distance_sq: float = point.distance_squared_to(on_triangle)
if distance_sq < closest_distance_sq:
closest_point = on_triangle
closest_distance_sq = distance_sq
return closest_point
printerr("Unsupported shape: ", shape)
return point


func _get_property_list() -> Array[Dictionary]:
var properties: Array[Dictionary] = []
match custom_gravity_type:
CustomGravityType.DIRECTIONAL:
properties.append({
"name": "direction",
"type": TYPE_VECTOR3,
"usage": PROPERTY_USAGE_DEFAULT,
})
CustomGravityType.DISC, CustomGravityType.TORUS:
properties.append({
"name": "radius",
"type": TYPE_FLOAT,
"usage": PROPERTY_USAGE_DEFAULT,
})
CustomGravityType.LINE:
properties.append({
"name": "line_points",
"type": TYPE_PACKED_VECTOR3_ARRAY,
"usage": PROPERTY_USAGE_DEFAULT,
})
CustomGravityType.SHAPED:
properties.append({
"name": "shape",
"type": TYPE_OBJECT,
"usage": PROPERTY_USAGE_DEFAULT,
"hint": PROPERTY_HINT_RESOURCE_TYPE,
"hint_string": "Shape3D"
})
return properties


# Everything below this point is for GLTF serialization.
func _get_or_create_state_shapes_in_state(gltf_state: GLTFState) -> Array:
var state_extensions: Dictionary = gltf_state.json.get_or_add("extensions", {})
if not state_extensions.has("OMI_physics_shape"):
state_extensions["OMI_physics_shape"] = {}
gltf_state.add_used_extension("OMI_physics_shape", false)
var omi_physics_shape_ext: Dictionary = state_extensions["OMI_physics_shape"]
var state_shapes: Array = omi_physics_shape_ext.get_or_add("shapes", [])
return state_shapes


func to_dictionary(gltf_state: GLTFState) -> Dictionary:
var ret: Dictionary = area_gravity_to_dictionary(self)
if gravity_type != Area3D.GravityType.GRAVITY_TYPE_TARGET:
return ret
var type_string: String = _gravity_type_enum_to_string(custom_gravity_type)
ret["type"] = type_string
var sub_dict: Dictionary = {}
if custom_gravity_type == CustomGravityType.DIRECTIONAL:
if not direction.is_equal_approx(Vector3.DOWN):
sub_dict = { "direction": [direction.x, direction.y, direction.z] }
else:
if gravity_point_unit_distance != 0.0:
sub_dict = { "unitDistance": gravity_point_unit_distance }
match custom_gravity_type:
CustomGravityType.DISC, CustomGravityType.TORUS:
if radius != 1.0:
sub_dict["radius"] = radius
CustomGravityType.LINE:
var point_numbers: Array = []
for line_point in line_points:
point_numbers.append(line_point.x)
point_numbers.append(line_point.y)
point_numbers.append(line_point.z)
sub_dict["points"] = point_numbers
CustomGravityType.SHAPED:
var state_shapes: Array = _get_or_create_state_shapes_in_state(gltf_state)
var gltf_shape := GLTFPhysicsShape.from_resource(shape)
sub_dict["shape"] = state_shapes.size()
state_shapes.append(gltf_shape.to_dictionary())
if not sub_dict.is_empty():
ret[type_string] = sub_dict
return ret


## Functionality common to all Godot Area3D nodes including non-CustomGravityArea3D nodes.
static func area_gravity_to_dictionary(area: Area3D) -> Dictionary:
var ret: Dictionary = {}
var space_override: Area3D.SpaceOverride = area.gravity_space_override
if space_override == Area3D.SpaceOverride.SPACE_OVERRIDE_DISABLED:
return ret
ret["gravity"] = area.gravity
if area.priority != 0:
ret["priority"] = area.priority
if space_override == Area3D.SpaceOverride.SPACE_OVERRIDE_REPLACE:
ret["replace"] = true
ret["stop"] = true
elif space_override == Area3D.SpaceOverride.SPACE_OVERRIDE_COMBINE_REPLACE:
ret["stop"] = true
elif space_override == Area3D.SpaceOverride.SPACE_OVERRIDE_REPLACE_COMBINE:
ret["replace"] = true
if area.gravity_type == Area3D.GravityType.GRAVITY_TYPE_DIRECTIONAL:
var dir: Vector3 = area.gravity_direction * area.global_basis.orthonormalized()
if not dir.is_equal_approx(Vector3.DOWN):
ret["directional"] = { "direction": [dir.x, dir.y, dir.z] }
ret["type"] = "directional"
elif area.gravity_type == Area3D.GravityType.GRAVITY_TYPE_POINT:
var unit_dist: float = area.gravity_point_unit_distance
if unit_dist != 0.0:
ret["point"] = { "unitDistance": unit_dist }
ret["type"] = "point"
return ret


static func from_dictionary(dict: Dictionary, gltf_state: GLTFState) -> CustomGravityArea3D:
if "type" not in dict:
printerr('GLTF gravity import: Missing required field "type", expected "directional", "point", "disc", "torus", "line", or "shaped".')
return null
if "gravity" not in dict:
printerr('GLTF gravity import: Missing required field "gravity", expected a number in meters per second squared.')
return null
var type_string = dict.get("type")
if type_string not in ["directional", "point", "disc", "torus", "line", "shaped"]:
printerr("GLTF gravity import: Invalid gravity type, found: ", dict.get("type"), ' but expected "directional", "point", "disc", "torus", "line", or "shaped".')
return null
var gravity_amount = dict.get("gravity")
if not gravity_amount is float: # All JSON numbers are floats.
printerr("GLTF gravity import: Invalid gravity, found: ", dict.get("gravity"), ' but expected a number.')
return null
var ret: CustomGravityArea3D = CustomGravityArea3D.new()
ret.gravity_type = Area3D.GRAVITY_TYPE_TARGET
ret.custom_gravity_type = _gravity_type_string_to_enum(type_string)
ret.gravity = gravity_amount
var priority = dict.get("priority")
if priority is float: # All JSON numbers are floats.
ret.priority = priority
var replace: bool = dict.get("replace", false)
var stop: bool = dict.get("stop", false)
if replace and stop:
ret.gravity_space_override = Area3D.SpaceOverride.SPACE_OVERRIDE_REPLACE
elif stop:
ret.gravity_space_override = Area3D.SpaceOverride.SPACE_OVERRIDE_COMBINE_REPLACE
elif replace:
ret.gravity_space_override = Area3D.SpaceOverride.SPACE_OVERRIDE_REPLACE_COMBINE
else:
ret.gravity_space_override = Area3D.SpaceOverride.SPACE_OVERRIDE_COMBINE
var sub_dict = dict.get(type_string)
if not sub_dict is Dictionary:
return ret
var direction = sub_dict.get("direction")
if direction is Array:
ret.direction = Vector3(direction[0], direction[1], direction[2])
var unit_distance = sub_dict.get("unitDistance")
if unit_distance is float:
ret.gravity_point_unit_distance = unit_distance
var radius = sub_dict.get("radius")
if radius is float:
ret.radius = radius
var points = sub_dict.get("points")
if points is Array:
var packed_points := PackedVector3Array()
for i in range(0, points.size(), 3):
packed_points.append(Vector3(points[i], points[i + 1], points[i + 2]))
ret.line_points = packed_points
var shape = sub_dict.get("shape")
if shape is float: # Integer but all JSON numbers are floats.
var shape_index: int = shape
if shape_index < 0:
printerr("GLTF gravity import: Invalid shape index, found: ", shape, " but expected a non-negative integer.")
return ret
var state_shapes: Array = gltf_state.get_additional_data(&"GLTFPhysicsShapes")
if shape_index >= state_shapes.size():
printerr("GLTF gravity import: Shape index ", shape_index, " is out of bounds (size=", state_shapes.size(), ").")
return ret
var gltf_shape: GLTFPhysicsShape = state_shapes[shape_index]
ret.shape = gltf_shape.to_resource(true)
return ret


static func _gravity_type_enum_to_string(type: CustomGravityType) -> String:
# The type value may be set to `"directional"`, `"point"`, `"disc"`, `"torus"`, `"line"`, or `"shaped"`.
match type:
CustomGravityType.DIRECTIONAL:
return "directional"
CustomGravityType.POINT:
return "point"
CustomGravityType.DISC:
return "disc"
CustomGravityType.TORUS:
return "torus"
CustomGravityType.LINE:
return "line"
CustomGravityType.SHAPED:
return "shaped"
assert(false, "GLTF gravity export: Invalid gravity type.")
return ""


static func _gravity_type_string_to_enum(type: String) -> CustomGravityType:
match type:
"directional":
return CustomGravityType.DIRECTIONAL
"point":
return CustomGravityType.POINT
"disc":
return CustomGravityType.DISC
"torus":
return CustomGravityType.TORUS
"line":
return CustomGravityType.LINE
"shaped":
return CustomGravityType.SHAPED
printerr("GLTF gravity import: Unknown gravity type: ", type)
return CustomGravityType.DIRECTIONAL
13 changes: 13 additions & 0 deletions addons/omi_extensions/physics_gravity/global_gravity_setter.gd
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class_name GlobalGravitySetter
extends Node


@export var gravity: float = 9.80665
@export var direction: Vector3 = Vector3.DOWN


func _ready() -> void:
var world_space_rid: RID = get_viewport().find_world_3d().space
PhysicsServer3D.area_set_param(world_space_rid, PhysicsServer3D.AREA_PARAM_GRAVITY, gravity)
PhysicsServer3D.area_set_param(world_space_rid, PhysicsServer3D.AREA_PARAM_GRAVITY_VECTOR, direction)
queue_free()
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