Class Accessor

An accessor defines a method for retrieving data as typed arrays from within a buffer view. See accessor in the glTF 2.0 specification

Inheritance

Object

Accessor

Inherited Members

Object.ToString()

Object.Equals(Object)

Object.Equals(Object, Object)

Object.ReferenceEquals(Object, Object)

Object.GetHashCode()

Object.GetType()

Object.MemberwiseClone()

Namespace: GLTFast.Schema

Syntax

[Serializable]
public class Accessor

Fields

bufferView

The index of the bufferView. If this is undefined, look in the sparse object for the index and value buffer views.

Declaration

public int bufferView

Field Value

Type	Description
Int32

byteOffset

The offset relative to the start of the bufferView in bytes. This must be a multiple of the size of the component datatype. 0

Declaration

public int byteOffset

Field Value

Type	Description
Int32

componentType

The datatype of components in the attribute. All valid values correspond to WebGL enums. The corresponding typed arrays are: Int8Array, Uint8Array, Int16Array, Uint16Array, Uint32Array, and Float32Array, respectively. 5125 (UNSIGNED_INT) is only allowed when the accessor contains indices i.e., the accessor is only referenced by primitive.indices.

Declaration

public GltfComponentType componentType

Field Value

Type	Description
GltfComponentType

count

The number of attributes referenced by this accessor, not to be confused with the number of bytes or number of components. 1

Declaration

public int count

Field Value

Type	Description
Int32

max

Maximum value of each component in this attribute. Both min and max arrays have the same length. The length is determined by the value of the type property; it can be 1, 2, 3, 4, 9, or 16.

When componentType is 5126 (FLOAT) each array value must be stored as double-precision JSON number with numerical value which is equal to buffer-stored single-precision value to avoid extra runtime conversions.

normalized property has no effect on array values: they always correspond to the actual values stored in the buffer. When accessor is sparse, this property must contain max values of accessor data with sparse substitution applied. 1 16

Declaration

public float[] max

Field Value

Type	Description
Single[]

min

Minimum value of each component in this attribute. Both min and max arrays have the same length. The length is determined by the value of the type property; it can be 1, 2, 3, 4, 9, or 16.

When componentType is 5126 (FLOAT) each array value must be stored as double-precision JSON number with numerical value which is equal to buffer-stored single-precision value to avoid extra runtime conversions.

normalized property has no effect on array values: they always correspond to the actual values stored in the buffer. When accessor is sparse, this property must contain min values of accessor data with sparse substitution applied. 1 16

Declaration

public float[] min

Field Value

Type	Description
Single[]

normalized

Specifies whether integer data values should be normalized (true) to [0, 1] (for unsigned types) or [-1, 1] (for signed types), or converted directly (false) when they are accessed. Must be false when accessor is used for animation data.

Declaration

public bool normalized

Field Value

Type	Description
Boolean

sparse

Sparse storage of attributes that deviate from their initialization value.

Declaration

public AccessorSparse sparse

Field Value

Type	Description
AccessorSparse

Properties

IsSparse

True if the accessor is sparse

Declaration

public bool IsSparse { get; }

Property Value

Type	Description
Boolean

Methods

GetAccessorAttributeType(Int32)

Get one-dimensional glTF attribute type by number of components per elements. Note that this does not support matrix types.

Declaration

public static GltfAccessorAttributeType GetAccessorAttributeType(int dimension)

Parameters

Type	Name	Description
Int32	dimension	Number of components per element

Returns

Type	Description
GltfAccessorAttributeType	Corresponding one-dimensional glTF attribute type

Exceptions

Type	Condition
ArgumentOutOfRangeException

GetAccessorAttributeTypeLength(GltfAccessorAttributeType)

Get number of components of glTF attribute type.

Declaration

public static int GetAccessorAttributeTypeLength(GltfAccessorAttributeType type)

Parameters

Type	Name	Description
GltfAccessorAttributeType	type	glTF attribute type

Returns

Type	Description
Int32	Number of components

Exceptions

Type	Condition
ArgumentOutOfRangeException

GetAttributeType()

GltfAccessorAttributeType typed/cached getter from the GLTFast.Schema.Accessor.type string.

Declaration

public GltfAccessorAttributeType GetAttributeType()

Returns

Type	Description
GltfAccessorAttributeType	The Accessor's attribute type, if it could be retrieved correctly. Undefined otherwise

GetComponentType(VertexAttributeFormat)

Converts Unity vertex attribute format to glTF component type.

Declaration

public static GltfComponentType GetComponentType(VertexAttributeFormat format)

Parameters

Type	Name	Description
VertexAttributeFormat	format	vertex attribute format

Returns

Type	Description
GltfComponentType	glTF component type

Exceptions

Type	Condition
ArgumentOutOfRangeException

GetComponentTypeSize(GltfComponentType)

Provides size of components by type

Declaration

public static int GetComponentTypeSize(GltfComponentType componentType)

Parameters

Type	Name	Description
GltfComponentType	componentType	glTF component type

Returns

Type	Description
Int32	Component size in bytes

Exceptions

Type	Condition
ArgumentOutOfRangeException

SetAttributeType(GltfAccessorAttributeType)

GltfAccessorAttributeType typed setter for the GLTFast.Schema.Accessor.type string.

Declaration

public void SetAttributeType(GltfAccessorAttributeType type)

Parameters

Type	Name	Description
GltfAccessorAttributeType	type	Attribute type

TryGetBounds()

For 3D positional data, returns accessor's bounding box. Applies coordinate system transform (glTF to Unity)

Declaration

public Bounds? TryGetBounds()

Returns

Type	Description
Nullable<Bounds>	Bounding box enclosing the minimum and maximum values