KHR_physics_rigid_bodies Draft Proposal

extensions/2.0/Khronos/KHR_physics_rigid_bodies/schema/geometry.schema.json

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+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "$id": "node.KHR_physics_rigid_bodies.collider.schema.json",
+    "title": "KHR_physics_rigid_bodies Node Collider Property",
+    "type": "object",
+    "description": "Parameters describing a shape used for collison detection and response.",
+    "allOf": [ { "$ref": "glTFProperty.schema.json" } ],
+    "properties": {
+        "convexHull": {
+            "type": "boolean",
+            "description": "Specifies whether the geometry should be used to generate a convex hull.",
+            "gltf_detailedDescription": "Specifies how the collision shape is generated from the geometry. When this value is false, the collision volume of this shape is determined byt the node or shape property. When this value is true, this shape should be a convex hull generated by the shape or node.",
+            "default": false
+        },
+        "extensions": { },
+        "extras": { }
+    },
+    "oneOf": [
+        "shape": {
+            "allOf": [{ "$ref": "glTFid.schema.json" }],
+            "description": "The index of the shape in the top level shapes array."
+        },
+        "node": {
+            "allOf": [{ "$ref": "glTFid.schema.json" }],
+            "description": "The index of a node providing mesh geometry."
+        }
+    ],
+    "required": [
+        "shape"
+    ]
+}

extensions/2.0/Khronos/KHR_physics_rigid_bodies/schema/glTF.KHR_physics_rigid_bodies.collision_filter.schema.json

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+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "$id": "glTF.KHR_physics_rigid_bodies.collision_filter.schema.json",
+    "title": "KHR_physics_rigid_bodies Collision Filter",
+    "type": "object",
+    "description": "Parameters describing a parameterization of a collision filter, allowing for disabling collision between pairs of shapes.",
+    "allOf": [ { "$ref": "glTFChildOfRootProperty.schema.json" } ],
+    "properties": {
+        "collisionSystems": {
+            "type": "array",
+            "description": "An array of strings representing the names of the collision systems of which this object is a member.",
+            "items": {
+                "type": "string"
+            }
+        },
+        "collideWithSystems": {
+            "type": "array",
+            "description": "An array of strings representing the name of the collision systems which this object can collide with.",
+            "items": {
+                "type": "string"
+            }
+        },
+        "notCollideWithSystems": {
+            "type": "array",
+            "description": "An array of strings representing the names of the collision systems which this object does not collide with.",
+            "items": {
+                "type": "string"
+            }
+        },
+        "extensions": { },
+        "extras": { }
+    },
+    "not": {
+        "anyOf": [
+            { "required": [ "collideWithSystems", "notCollideWithSystems" ] }
+        ]
+    }
+}

extensions/2.0/Khronos/KHR_physics_rigid_bodies/schema/glTF.KHR_physics_rigid_bodies.joint.drive.schema.json

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+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "$id": "glTF.KHR_physics_rigid_bodies.joint.drive.schema.json",
+    "title": "KHR_physics_rigid_bodies Physics Joint Drive",
+    "type": "object",
+    "description": "Parameters describing a drive or motor which applies forces within a joint.",
+    "allOf": [ { "$ref": "glTFProperty.schema.json" } ],
+    "properties": {
+        "type": {
+            "description": "Determines the degree of freedom which this drive controls.",
+            "anyOf": [
+                {
+                    "const": "linear",
+                    "description": "The drive applies a linear force along the driven axis."
+                },
+                {
+                    "const": "angular",
+                    "description": "The drive applies a torque about the driven axis."
+                },
+                {
+                    "type": "string"
+                }
+            ]
+        },
+        "mode": {
+            "description": "Specifies the force calculation mode.",
+            "anyOf": [
+                {
+                    "const": "force",
+                    "description": "Value computed from the spring equation is the force to apply along the axis."
+                },
+                {
+                    "const": "acceleration",
+                    "description": "Value computed from the spring equation is the acceleration to apply along the axis."
+                },
+                {
+                    "type": "string"
+                }
+            ]
+        },
+        "axis": {
+            "type": "integer",
+            "minimum": 0,
+            "maximum": 2,
+            "description": "The index of the axis which this drive applies forces on."
+        },
+        "maxForce": {
+            "type": "number",
+            "description": "The maximum force (or torque, for angular drives) the drive can apply. If not provided, this drive is not force-limited.",
+            "minimum": 0
+        },
+        "positionTarget": {
+            "type": "number",
+            "description": "The target translation or angle along/about the axis that this drive attempts to achieve."
+        },
+        "velocityTarget": {
+            "type": "number",
+            "description": "The target linear velocity or angular velocity along/about the axis that this drive attempts to achieve."
+        },
+        "stiffness": {
+            "type": "number",
+            "description": "The stiffness of the drive, scaling the force based on the position target.",
+            "default": 0,
+            "minimum": 0
+        },
+        "damping": {
+            "type": "number",
+            "description": "The damping of the drive, scaling the force based on the velocity target.",
+            "default": 0,
+            "minimum": 0
+        }
+    },
+    "required": [
+        "type",
+        "mode",
+        "axis"
+    ],
+    "dependencies": {
+        "positionTarget": [ "stiffness" ],
+        "stiffness": [ "positionTarget" ],
+        "velocityTarget": [ "damping" ],
+        "damping": [ "velocityTarget" ]
+    }
+}

extensions/2.0/Khronos/KHR_physics_rigid_bodies/schema/glTF.KHR_physics_rigid_bodies.joint.limit.schema.json

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+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "$id": "glTF.KHR_physics_rigid_bodies.joint.limit.schema.json",
+    "title": "KHR_physics_rigid_bodies Physics Joint Limit",
+    "type": "object",
+    "description": "Parameters describing how a joint constrains the relative motion of a pair of nodes.",
+    "allOf": [ { "$ref": "glTFProperty.schema.json" } ],
+    "properties": {
+        "min": {
+            "type": "number",
+            "description": "The minimum of the allowed range of relative distance in meters, or angle in radians."
+        },
+        "max": {
+            "type": "number",
+            "description": "The maximum of the allowed range of relative distance in meters, or angle in radians."
+        },
+        "stiffness": {
+            "type": "number",
+            "description": "The spring constant used to calculate a restorative force when the joint is extended beyond the limit. If not present, the limit should be infinitely stiff.",
+            "minimum": 0.0
+        },
+        "damping": {
+            "type": "number",
+            "description": "Damping applied to the velocity when the joint is extended beyond the limit.",
+            "minimum": 0.0,
+            "default": 0.0
+        },
+        "extensions": { },
+        "extras": { }
+    },
+    "oneOf": [
+        {
+            "type": "object",
+            "properties": {
+                "linearAxes": {
+                    "description": "The indices of the linear axes which are limited, constraining the linear motion in 1, 2 or 3 dimensions. 1D keeps an object some distance from an infinite plane. 2D keeps an object some distance from an infinite line. 3D keeps an object some distance from a point. Can only contain 0 (X), 1 (Y), or 2 (Z), so [0, 1, 2] constrains all three axes.",
+                    "type": "array",
+                    "items": {
+                        "type": "integer",
+                        "minimum": 0,
+                        "maximum": 2
+                    },
+                    "minItems": 1,
+                    "maxItems": 3,
+                    "uniqueItems": true
+                }
+            },
+            "required": ["linearAxes"]
+        },
+        {
+            "type": "object",
+            "properties": {
+                "angularAxes": {
+                    "description": "The indices of the angular axes which are limited, constraining the angular motion in 1, 2 or 3 dimensions. 1D limits rotation about one axis (e.g. a universal joint). 2D limits rotation about two axes (e.g. a cone). 3D limits rotation about all three axes. Can only contain 0 (X), 1 (Y), or 2 (Z), so [0, 1, 2] constrains all three axes.",
+                    "type": "array",
+                    "items": {
+                        "type": "integer",
+                        "minimum": 0,
+                        "maximum": 2
+                    },
+                    "minItems": 1,
+                    "maxItems": 3,
+                    "uniqueItems": true
+                }
+            },
+            "required": ["angularAxes"]
+        }
+    ]
+}

extensions/2.0/Khronos/KHR_physics_rigid_bodies/schema/glTF.KHR_physics_rigid_bodies.joint.schema.json

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+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "$id": "glTF.KHR_physics_rigid_bodies.joint.schema.json",
+    "title": "KHR_physics_rigid_bodies Physics Joint",
+    "type": "object",
+    "description": "Parameters describing a joint, which may constrain or drive the relative motion of a pair of nodes.",
+    "allOf": [ { "$ref": "glTFChildOfRootProperty.schema.json" } ],
+    "properties": {
+        "limits": {
+            "type": "array",
+            "description": "The set of limits which constrain relative motion.",
+            "items": {
+                "type": "object",
+                "$ref": "glTF.KHR_physics_rigid_bodies.joint.limit.schema.json"
+            }
+        },
+        "drives": {
+            "type": "array",
+            "description": "The set of drives applying forces to this joint.",
+            "items": {
+                "type": "object",
+                "$ref": "glTF.KHR_physics_rigid_bodies.joint.drive.schema.json"
+            }
+        },
+        "extensions": { },
+        "extras": { }
+    }
+}

extensions/2.0/Khronos/KHR_physics_rigid_bodies/schema/glTF.KHR_physics_rigid_bodies.joint_drive.schema.json

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+{
+    "$schema": "http://json-schema.org/draft-04/schema",
+    "title": "KHR_physics_rigid_bodies Physics Joint Drive",
+    "type": "object",
+    "description": "Parameters describing a drive which applies forces within a joint.",
+    "allOf": [ { "$ref": "glTFProperty.schema.json" } ],
+    "properties": {
+        "type": {
+            "description": "Determines the degree of freedom which this drive controls.",
+            "anyOf": [
+                {
+                    "enum": [ "linear" ],
+                    "description": "The drive applies a linear force along the driven axis."
+                },
+                {
+                    "enum": [ "angular" ],
+                    "description": "The drive applies a torque about the driven axis."
+                },
+                {
+                    "type": "string"
+                }
+            ]
+        },
+        "mode": {
+            "description": "Specifies the force calculation mode.",
+            "anyOf": [
+                {
+                    "enum": [ "force" ],
+                    "description": "Value computed from the spring equation is the force to apply along the axis."
+                },
+                {
+                    "enum": [ "acceleration" ],
+                    "description": "Value computed from the spring equation is the acceleration to apply along the axis."
+                },
+                {
+                    "type": "string"
+                }
+            ]
+        },
+        "axis": {
+            "type": "integer",
+            "minimum": 0,
+            "maximum": 3,
+            "description": "The index of the axis which this drive applies forces on."
+        },
+        "maxForce": {
+            "type": "number",
+            "description": "The maximum force (or torque, for angular drives) the drive can apply. If not provided, this drive is not force-limited.",
+            "minimum": 0
+        },
+        "positionTarget": {
+            "type": "number",
+            "description": "The target translation/angle along the axis that this drive attempts to achieve."
+        },
+        "velocityTarget": {
+            "type": "number",
+            "description": "The target velocity along/about the axis that this drive attempts to achieve."
+        },
+        "stiffness": {
+            "type": "number",
+            "description": "The stiffness of the drive, scaling the force based on the position target.",
+            "default": 0,
+            "minimum": 0
+        },
+        "damping": {
+            "type": "number",
+            "description": "The damping of the drive, scaling the force based on the velocity target.",
+            "default": 0,
+            "minimum": 0
+        }
+    ],
+    "required": [
+        "type",
+        "mode",
+        "axis"
+    ]
+}

extensions/2.0/Khronos/KHR_physics_rigid_bodies/schema/glTF.KHR_physics_rigid_bodies.material.schema.json

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+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "$id": "glTF.KHR_physics_rigid_bodies.material.schema.json",
+    "title": "KHR_physics_rigid_bodies Physics Material",
+    "type": "object",
+    "description": "Parameters describing the collision response of a surface in a physics simulation.",
+    "allOf": [ { "$ref": "glTFChildOfRootProperty.schema.json" } ],
+    "properties": {
+        "staticFriction": {
+            "type": "number",
+            "description": "The friction used when an object is laying still on a surface. Usually a value from 0 to 1. A value of 0 feels like ice, a value of 1 will make it very hard to get the object moving. Simulations which do not differentiate between static and dynamic friction should use the dynamic friction value.",
+            "minimum": 0.0,
+            "default": 0.6
+        },
+        "dynamicFriction": {
+            "type": "number",
+            "description": "The friction used when already moving. Usually a value from 0 to 1. A value of 0 feels like ice, a value of 1 will make it come to rest very quickly unless a lot of force or gravity pushes the object.",
+            "minimum": 0.0,
+            "default": 0.6
+        },
+        "restitution": {
+            "type": "number",
+            "description": "How bouncy is the surface? A value of 0 will not bounce. A value of 1 will bounce without any loss of energy.",
+            "minimum": 0.0,
+            "default": 0.0
+        },
+        "frictionCombine": {
+            "type": "string",
+            "description": "Determines how friction should be combined when two objects interact.",
+            "enum": ["average", "minimum", "maximum", "multiply"]
+        },
+        "restitutionCombine": {
+            "type": "string",
+            "description": "Determines how restitution should be combined when two objects interact.",
+            "enum": ["average", "minimum", "maximum", "multiply"]
+        },
+        "extensions": { },
+        "extras": { }
+    }
+}