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
NamedObject
Accessor
Inherited Members
Namespace: Unity.Cloud.Gltfast.Objects
Assembly: Unity.Cloud.Gltfast.dll
Syntax
[MovedFrom(true, "GLTFast.Schema", "glTFast", null)]
public class Accessor : NamedObject

Properties

AdditionalProperties

Additional properties on glTF JSON objects. Those properties may have been added by a new, unsupported version of the glTF specification. For extending glTF, please use extensions or extras instead.

Declaration
[JsonIgnore]
public ReadOnlyProperties AdditionalProperties { get; }
Property Value
Type Description
ReadOnlyProperties

BufferView

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

Declaration
[JsonPropertyName("bufferView")]
public int? BufferView { get; set; }
Property Value
Type Description
int?

ByteOffset

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

Declaration
[JsonPropertyName("byteOffset")]
public int ByteOffset { get; set; }
Property Value
Type Description
int

ByteSize

Overall, byte size. Ignores interleaved or sparse accessors

Declaration
[JsonIgnore]
public int ByteSize { get; }
Property Value
Type Description
int

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
[JsonPropertyName("componentType")]
public AccessorDataType ComponentType { get; set; }
Property Value
Type Description
AccessorDataType

Count

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

Declaration
[JsonPropertyName("count")]
public int Count { get; set; }
Property Value
Type Description
int

ElementByteSize

Byte size of one element

Declaration
[JsonIgnore]
public int ElementByteSize { get; }
Property Value
Type Description
int

Extensions

JSON object with extension-specific objects.

Declaration
[JsonPropertyName("extensions")]
public AccessorExtensions Extensions { get; set; }
Property Value
Type Description
AccessorExtensions
See Also

Extras

Application-specific data.

Declaration
[JsonPropertyName("extras")]
[JsonConverter(typeof(ExtrasConverter))]
public ExtrasContainer Extras { get; set; }
Property Value
Type Description
ExtrasContainer
See Also

IsSparse

True if the accessor is sparse

Declaration
[JsonIgnore]
public bool IsSparse { get; }
Property Value
Type Description
bool

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.

Declaration
[JsonPropertyName("max")]
[JsonConverter(typeof(DoubleListConverter))]
public List<double> Max { get; set; }
Property Value
Type Description
List<double>

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.

Declaration
[JsonPropertyName("min")]
[JsonConverter(typeof(DoubleListConverter))]
public List<double> Min { get; set; }
Property Value
Type Description
List<double>

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
[JsonPropertyName("normalized")]
public bool Normalized { get; set; }
Property Value
Type Description
bool

Sparse

Sparse storage of attributes that deviate from their initialization value.

Declaration
[JsonPropertyName("sparse")]
public AccessorSparse Sparse { get; set; }
Property Value
Type Description
AccessorSparse

Type

Specifies if the accessor’s elements are scalars, vectors, or matrices.

Declaration
[JsonPropertyName("type")]
[JsonConverter(typeof(AccessorTypeValueConverter))]
public EnumOrRawValue<AccessorType> Type { get; set; }
Property Value
Type Description
EnumOrRawValue<AccessorType>
See Also

Methods

GetAccessorAttributeType(int)

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

Declaration
public static AccessorType GetAccessorAttributeType(int dimension)
Parameters
Type Name Description
int dimension

Number of components per element
Returns
Type Description
AccessorType

Corresponding one-dimensional glTF attribute type
Exceptions
Type Condition
ArgumentOutOfRangeException

Thrown when dimension is not between 1 and 4.

GetAccessorAttributeTypeLength(AccessorType)

Get number of components of glTF attribute type.

Declaration
public static int GetAccessorAttributeTypeLength(AccessorType type)
Parameters
Type Name Description
AccessorType type

glTF attribute type
Returns
Type Description
int

Number of components
Exceptions
Type Condition
ArgumentOutOfRangeException

Thrown when the value of type is unknown.

GetComponentType(VertexAttributeFormat)

Converts Unity vertex attribute format to glTF component type.

Declaration
public static AccessorDataType GetComponentType(VertexAttributeFormat format)
Parameters
Type Name Description
VertexAttributeFormat format

vertex attribute format
Returns
Type Description
AccessorDataType

glTF component type
Exceptions
Type Condition
ArgumentOutOfRangeException

Thrown when the value of format is unknown.

GetComponentTypeSize(AccessorDataType)

Provides size of components by type

Declaration
public static int GetComponentTypeSize(AccessorDataType componentType)
Parameters
Type Name Description
AccessorDataType componentType

glTF component type
Returns
Type Description
int

Component size in bytes
Exceptions
Type Condition
ArgumentOutOfRangeException

Thrown when value of ComponentType is unknown

TryGetBounds()

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

Declaration
public Bounds? TryGetBounds()
Returns
Type Description
Bounds?

Bounding box enclosing the minimum and maximum values