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glTF 2.0 property reference - for review
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gltfproperties.md

Objects

accessor

A typed view into a bufferView. A bufferView contains raw binary data. An accessor provides a typed view into a bufferView or a subset of a bufferView similar to how WebGL's vertexAttribPointer() defines an attribute in a buffer.

Properties

Type Description Required
bufferView integer The index of the bufferView. No
byteOffset integer The offset relative to the start of the bufferView in bytes. No, default: 0
componentType integer The datatype of components in the attribute. ✅ Yes
normalized boolean Specifies whether integer data values should be normalized. No, default: false
count integer The number of attributes referenced by this accessor. ✅ Yes
type string Specifies if the attribute is a scalar, vector, or matrix. ✅ Yes
max number[1-16] Maximum value of each component in this attribute. ✅ Yes
min number[1-16] Minimum value of each component in this attribute. ✅ Yes
sparse object Sparse storage of attributes that deviate from their initialization value. ✅ Yes
name string The user-defined name of this object. No
extensions object Dictionary object with extension-specific objects. No
extras any Application-specific data. No

Additional properties are allowed.

accessor.bufferView

The index of the bufferView.

  • Type: integer
  • Required: No
  • Minimum: >= 0

accessor.byteOffset

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

  • Type: integer
  • Required: No, default: 0
  • Minimum: >= 0
  • Related WebGL functions: vertexAttribPointer() offset parameter

accessor.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.

  • Type: integer
  • Required: Yes
  • Allowed values: 5120 (BYTE), 5121 (UNSIGNED_BYTE), 5122 (SHORT), 5123 (UNSIGNED_SHORT), 5125 (UNSIGNED_INT), 5126 (FLOAT)
  • Related WebGL functions: vertexAttribPointer() type parameter

accessor.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.

  • Type: boolean
  • Required: No, default: false
  • Related WebGL functions: vertexAttribPointer() normalized parameter

accessor.count ✅

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

  • Type: integer
  • Required: Yes
  • Minimum: >= 1

accessor.type ✅

Specifies if the attribute is a scalar, vector, or matrix.

  • Type: string
  • Required: Yes
  • Allowed values: "SCALAR", "VEC2", "VEC3", "VEC4", "MAT2", "MAT3", "MAT4"

accessor.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.

  • Type: number[1-16]
  • Required: Yes

accessor.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.

  • Type: number[1-16]
  • Required: Yes

accessor.sparse ✅

Sparse storage of attributes that deviate from their initialization value.

  • Type: object
  • Required: Yes

accessor.name

The user-defined name of this object. This is not necessarily unique, e.g., an accessor and a buffer could have the same name, or two accessors could even have the same name.

  • Type: string
  • Required: No

accessor.extensions

Dictionary object with extension-specific objects.

  • Type: object
  • Required: No
  • Type of each property: extension

accessor.extras

Application-specific data.

  • Type: any
  • Required: No

animation

A keyframe animation.

Properties

Type Description Required
channels channel[1-*] An array of channels, each of which targets an animation's sampler at a node's property. Different channels of the same animation can't have equal targets. ✅ Yes
samplers animation sampler[1-*] An array of samplers that combines input and output accessors with an interpolation algorithm to define a keyframe graph (but not its target). ✅ Yes
name string The user-defined name of this object. No
extensions object Dictionary object with extension-specific objects. No
extras any Application-specific data. No

Additional properties are allowed.

animation.channels ✅

An array of channels, each of which targets an animation's sampler at a node's property. Different channels of the same animation can't have equal targets.

animation.samplers ✅

An array of samplers that combines input and output accessors with an interpolation algorithm to define a keyframe graph (but not its target).

animation.name

The user-defined name of this object. This is not necessarily unique, e.g., an accessor and a buffer could have the same name, or two accessors could even have the same name.

  • Type: string
  • Required: No

animation.extensions

Dictionary object with extension-specific objects.

  • Type: object
  • Required: No
  • Type of each property: extension

animation.extras

Application-specific data.

  • Type: any
  • Required: No

animation sampler

Combines input and output accessors with an interpolation algorithm to define a keyframe graph (but not its target).

Properties

Type Description Required
input integer The index of an accessor containing keyframe input values, e.g., time. ✅ Yes
interpolation string Interpolation algorithm. No, default: "LINEAR"
output integer The index of an accessor, containing keyframe output values. ✅ Yes
extensions object Dictionary object with extension-specific objects. No
extras any Application-specific data. No

Additional properties are allowed.

animation sampler.input ✅

The index of an accessor containing keyframe input values, e.g., time. That accessor must have componentType FLOAT. The values represent time in seconds with time[0] >= 0.0, and strictly increasing values, i.e., time[n + 1] > time[n].

  • Type: integer
  • Required: Yes
  • Minimum: >= 0

animation sampler.interpolation

Interpolation algorithm. When an animation targets a node's rotation, and the animation's interpolation is "LINEAR", spherical linear interpolation (slerp) should be used to interpolate quaternions. When interpolation is "STEP", animated value remains constant to the value of the first point of the timeframe, until the next timeframe.

  • Type: string
  • Required: No, default: "LINEAR"
  • Allowed values: "LINEAR (When an animation targets a node's rotation, and the animation's interpolation is "LINEAR", spherical linear interpolation (slerp) should be used to interpolate quaternions.)", "STEP (When interpolation is "STEP", animated value remains constant to the value of the first point of the timeframe, until the next timeframe.)", "CATMULLROMSPLINE (When interpolation is "CATMULLROMSPLINE", the animation's interpolation is computed using a uniform Catmull-Rom spline.)", "CUBICSPLINE (When interpolation is "CUBICSPLINE", the animation's interpolation is computed using a cubic spline with specified tangents. For each input value, the output stores three values: in-tangent, spline vertex, and out-tangent.)"

animation sampler.output ✅

The index of an accessor, containing keyframe output values. Output and input accessors must have the same count except for CUBICSPLINE where output count is 3x the input count. When sampler is used with TRS target, output accessor's componentType must be FLOAT.

  • Type: integer
  • Required: Yes
  • Minimum: >= 0

animation sampler.extensions

Dictionary object with extension-specific objects.

  • Type: object
  • Required: No
  • Type of each property: extension

animation sampler.extras

Application-specific data.

  • Type: any
  • Required: No

asset

Metadata about the glTF asset.

Properties

Type Description Required
copyright string A copyright message suitable for display to credit the content creator. No
generator string Tool that generated this glTF model. Useful for debugging. No
version string The glTF version that this asset targets. ✅ Yes
minVersion string The minimum glTF version that this asset targets. No
extensions object Dictionary object with extension-specific objects. No
extras any Application-specific data. No

Additional properties are allowed.

asset.copyright

A copyright message suitable for display to credit the content creator.

  • Type: string
  • Required: No

asset.generator

Tool that generated this glTF model. Useful for debugging.

  • Type: string
  • Required: No

asset.version ✅

The glTF version that this asset targets.

  • Type: string
  • Required: Yes

asset.minVersion

The minimum glTF version that this asset targets.

  • Type: string
  • Required: No

asset.extensions

Dictionary object with extension-specific objects.

  • Type: object
  • Required: No
  • Type of each property: extension

asset.extras

Application-specific data.

  • Type: any
  • Required: No

attribute

A dictionary object, where each key corresponds to mesh attribute semantic and each value is the index of the accessor containing attribute's data.

buffer

A buffer points to binary geometry, animation, or skins.

Properties

Type Description Required
uri string The uri of the buffer. No
byteLength integer The length of the buffer in bytes. ✅ Yes
name string The user-defined name of this object. No
extensions object Dictionary object with extension-specific objects. No
extras any Application-specific data. No

Additional properties are allowed.

buffer.uri

The uri of the buffer. Relative paths are relative to the .gltf file. Instead of referencing an external file, the uri can also be a data-uri.

  • Type: string
  • Required: No
  • Format: uriref

buffer.byteLength ✅

The length of the buffer in bytes.

  • Type: integer
  • Required: Yes
  • Minimum: >= 0

buffer.name

The user-defined name of this object. This is not necessarily unique, e.g., an accessor and a buffer could have the same name, or two accessors could even have the same name.

  • Type: string
  • Required: No

buffer.extensions

Dictionary object with extension-specific objects.

  • Type: object
  • Required: No
  • Type of each property: extension

buffer.extras

Application-specific data.

  • Type: any
  • Required: No

bufferView

A view into a buffer generally representing a subset of the buffer.

Properties

Type Description Required
buffer integer The index of the buffer. ✅ Yes
byteOffset integer The offset into the buffer in bytes. ✅ Yes
byteLength integer The length of the bufferView in bytes. ✅ Yes
byteStride integer The stride, in bytes. No, default: 0
target integer The target that the WebGL buffer should be bound to. No
name string The user-defined name of this object. No
extensions object Dictionary object with extension-specific objects. No
extras any Application-specific data. No

Additional properties are allowed.

bufferView.buffer ✅

The index of the buffer.

  • Type: integer
  • Required: Yes
  • Minimum: >= 0

bufferView.byteOffset ✅

The offset into the buffer in bytes.

  • Type: integer
  • Required: Yes
  • Minimum: >= 0

bufferView.byteLength ✅

The length of the bufferView in bytes.

  • Type: integer
  • Required: Yes
  • Minimum: >= 0

bufferView.byteStride

The stride, in bytes, between vertex attributes or other interleavable data. When this is zero, data is tightly packed.

  • Type: integer
  • Required: No, default: 0
  • Minimum: >= 0
  • Maximum: <= 255
  • Related WebGL functions: vertexAttribPointer() stride parameter

bufferView.target

The target that the WebGL buffer should be bound to. All valid values correspond to WebGL enums. When this is not provided, the bufferView contains animation or skin data.

  • Type: integer
  • Required: No
  • Allowed values: 34962 (ARRAY_BUFFER), 34963 (ELEMENT_ARRAY_BUFFER)
  • Related WebGL functions: bindBuffer()

bufferView.name

The user-defined name of this object. This is not necessarily unique, e.g., an accessor and a buffer could have the same name, or two accessors could even have the same name.

  • Type: string
  • Required: No

bufferView.extensions

Dictionary object with extension-specific objects.

  • Type: object
  • Required: No
  • Type of each property: extension

bufferView.extras

Application-specific data.

  • Type: any
  • Required: No

camera

A camera's projection. A node can reference a camera to apply a transform to place the camera in the scene.

Properties

Type Description Required
orthographic object An orthographic camera containing properties to create an orthographic projection matrix. ✅ Yes
perspective object A perspective camera containing properties to create a perspective projection matrix. ✅ Yes
type string Specifies if the camera uses a perspective or orthographic projection. ✅ Yes
name string The user-defined name of this object. No
extensions object Dictionary object with extension-specific objects. No
extras any Application-specific data. No

Additional properties are allowed.

camera.orthographic ✅

An orthographic camera containing properties to create an orthographic projection matrix.

  • Type: object
  • Required: Yes

camera.perspective ✅

A perspective camera containing properties to create a perspective projection matrix.

  • Type: object
  • Required: Yes

camera.type ✅

Specifies if the camera uses a perspective or orthographic projection. Based on this, either the camera's perspective or orthographic property will be defined.

  • Type: string
  • Required: Yes
  • Allowed values: "perspective", "orthographic"

camera.name

The user-defined name of this object. This is not necessarily unique, e.g., an accessor and a buffer could have the same name, or two accessors could even have the same name.

  • Type: string
  • Required: No

camera.extensions

Dictionary object with extension-specific objects.

  • Type: object
  • Required: No
  • Type of each property: extension

camera.extras

Application-specific data.

  • Type: any
  • Required: No

channel

Targets an animation's sampler at a node's property.

Properties

Type Description Required
sampler integer The index of a sampler in this animation used to compute the value for the target. ✅ Yes
target object The index of the node and TRS property to target. ✅ Yes
extensions object Dictionary object with extension-specific objects. No
extras any Application-specific data. No

Additional properties are allowed.

channel.sampler ✅

The index of a sampler in this animation used to compute the value for the target, e.g., a node's translation, rotation, or scale (TRS).

  • Type: integer
  • Required: Yes
  • Minimum: >= 0

channel.target ✅

The index of the node and TRS property to target.

  • Type: object
  • Required: Yes

channel.extensions

Dictionary object with extension-specific objects.

  • Type: object
  • Required: No
  • Type of each property: extension

channel.extras

Application-specific data.

  • Type: any
  • Required: No

extension

Dictionary object with extension-specific objects.

Properties

Type Description Required

Additional properties are allowed.

extras

Application-specific data.

glTF

The root object for a glTF asset.

Properties

Type Description Required
extensionsUsed string[1-*] Names of glTF extensions used somewhere in this asset. No
extensionsRequired string[1-*] Names of glTF extensions required to properly load this asset. No
accessors accessor[1-*] An array of accessors. No
animations animation[1-*] An array of keyframe animations. No
asset object Metadata about the glTF asset. ✅ Yes
buffers buffer[1-*] An array of buffers. No
bufferViews bufferView[1-*] An array of bufferViews. No
cameras camera[1-*] An array of cameras. No
images image[1-*] An array of images. No
materials material[1-*] An array of materials. No
meshes mesh[1-*] An array of meshes. No
nodes node[1-*] An array of nodes. No
samplers sampler[1-*] An array of samplers. No
scene integer The index of the default scene. No
scenes scene[1-*] An array of scenes. No
skins skin[1-*] An array of skins. No
textures texture[1-*] An array of textures. No
extensions object Dictionary object with extension-specific objects. No
extras any Application-specific data. No

Additional properties are allowed.

glTF.extensionsUsed

Names of glTF extensions used somewhere in this asset.

  • Type: string[1-*]
    • Each element in the array must be unique.
  • Required: No

glTF.extensionsRequired

Names of glTF extensions required to properly load this asset.

  • Type: string[1-*]
    • Each element in the array must be unique.
  • Required: No

glTF.accessors

An array of accessors. An accessor is a typed view into a bufferView.

glTF.animations

An array of keyframe animations.

glTF.asset ✅

Metadata about the glTF asset.

  • Type: object
  • Required: Yes

glTF.buffers

An array of buffers. A buffer points to binary geometry, animation, or skins.

  • Type: buffer[1-*]
  • Required: No

glTF.bufferViews

An array of bufferViews. A bufferView is a view into a buffer generally representing a subset of the buffer.

glTF.cameras

An array of cameras. A camera defines a projection matrix.

  • Type: camera[1-*]
  • Required: No

glTF.images

An array of images. An image defines data used to create a texture.

  • Type: image[1-*]
  • Required: No

glTF.materials

An array of materials. A material defines the appearance of a primitive.

glTF.meshes

An array of meshes. A mesh is a set of primitives to be rendered.

  • Type: mesh[1-*]
  • Required: No

glTF.nodes

An array of nodes.

  • Type: node[1-*]
  • Required: No

glTF.samplers

An array of samplers. A sampler contains properties for texture filtering and wrapping modes.

glTF.scene

The index of the default scene.

  • Type: integer
  • Required: No
  • Minimum: >= 0

glTF.scenes

An array of scenes.

  • Type: scene[1-*]
  • Required: No

glTF.skins

An array of skins. A skin is defined by joints and matrices.

  • Type: skin[1-*]
  • Required: No

glTF.textures

An array of textures.

glTF.extensions

Dictionary object with extension-specific objects.

  • Type: object
  • Required: No
  • Type of each property: extension

glTF.extras

Application-specific data.

  • Type: any
  • Required: No

image

Image data used to create a texture. Image can be referenced by URI or bufferView index. mimeType is required in the latter case.

Properties

Type Description Required
uri string The uri of the image. No
mimeType string The image's MIME type. No
bufferView integer The index of the bufferView that contains the image. Use this instead of the image's uri property. No
name string The user-defined name of this object. No
extensions object Dictionary object with extension-specific objects. No
extras any Application-specific data. No

Additional properties are allowed.

image.uri

The uri of the image. Relative paths are relative to the .gltf file. Instead of referencing an external file, the uri can also be a data-uri. The image format must be jpg or png.

  • Type: string
  • Required: No
  • Format: uriref

image.mimeType

The image's MIME type.

  • Type: string
  • Required: No
  • Allowed values: "image/jpeg", "image/png"

image.bufferView

The index of the bufferView that contains the image. Use this instead of the image's uri property.

  • Type: integer
  • Required: No
  • Minimum: >= 0

image.name

The user-defined name of this object. This is not necessarily unique, e.g., an accessor and a buffer could have the same name, or two accessors could even have the same name.

  • Type: string
  • Required: No

image.extensions

Dictionary object with extension-specific objects.

  • Type: object
  • Required: No
  • Type of each property: extension

image.extras

Application-specific data.

  • Type: any
  • Required: No

indices

Indices of those attributes that deviate from their initialization value.

Properties

Type Description Required
bufferView integer The index of the bufferView with sparse indices. Referenced bufferView can't have ARRAY_BUFFER or ELEMENT_ARRAY_BUFFER target. ✅ Yes
byteOffset integer The offset relative to the start of the bufferView in bytes. Must be aligned. No, default: 0
componentType integer The indices data type. ✅ Yes
extensions object Dictionary object with extension-specific objects. No
extras any Application-specific data. No

Additional properties are allowed.

indices.bufferView ✅

The index of the bufferView with sparse indices. Referenced bufferView can't have ARRAY_BUFFER or ELEMENT_ARRAY_BUFFER target.

  • Type: integer
  • Required: Yes
  • Minimum: >= 0

indices.byteOffset

The offset relative to the start of the bufferView in bytes. Must be aligned.

  • Type: integer
  • Required: No, default: 0
  • Minimum: >= 0

indices.componentType ✅

The indices data type. Valid values correspond to WebGL enums: 5121 (UNSIGNED_BYTE), 5123 (UNSIGNED_SHORT), 5125 (UNSIGNED_INT).

  • Type: integer
  • Required: Yes
  • Allowed values: 5121 (UNSIGNED_BYTE), 5123 (UNSIGNED_SHORT), 5125 (UNSIGNED_INT)

indices.extensions

Dictionary object with extension-specific objects.

  • Type: object
  • Required: No
  • Type of each property: extension

indices.extras

Application-specific data.

  • Type: any
  • Required: No

material

The material appearance of a primitive.

Properties

Type Description Required
name string The user-defined name of this object. No
extensions object Dictionary object with extension-specific objects. No
extras any Application-specific data. No
pbrMetallicRoughness object A set of parameter values that are used to define the metallic-roughness material model from Physically-Based Rendering (PBR) methodology. No
normalTexture object The normal map texture. ✅ Yes
occlusionTexture object The occlusion map texture. ✅ Yes
emissiveTexture object The emissive map texture. ✅ Yes
emissiveFactor number[3] The emissive color of the material. No, default: [0,0,0]
alphaMode string The alpha rendering mode of the material. No, default: "OPAQUE"
alphaCutoff number The alpha cutoff value of the material. No, default: 0.5
doubleSided boolean Specifies whether the material is double sided. No, default: false

Additional properties are allowed.

material.name

The user-defined name of this object. This is not necessarily unique, e.g., an accessor and a buffer could have the same name, or two accessors could even have the same name.

  • Type: string
  • Required: No

material.extensions

Dictionary object with extension-specific objects.

  • Type: object
  • Required: No
  • Type of each property: extension

material.extras

Application-specific data.

  • Type: any
  • Required: No

material.pbrMetallicRoughness

A set of parameter values that are used to define the metallic-roughness material model from Physically-Based Rendering (PBR) methodology.

  • Type: object
  • Required: No

material.normalTexture ✅

A tangent space normal map. Each texel represents the XYZ components of a normal vector in tangent space. <TODO: Add more explaination on how XYZ is calculated>.

  • Type: object
  • Required: Yes

material.occlusionTexture ✅

The occlusion map texture. The occlusion values are sampled from the R channel. Higher values indicate areas that should receive full indirect lighting and lower values indicate no indirect lighting. These values are linear. If other channels are present (GBA), they are ignored for occlusion calculations.

  • Type: object
  • Required: Yes

material.emissiveTexture ✅

The emissive map controls the color and intensity of the light being emitted by the material. This texture contains RGB components in sRGB color space. If a fourth component (A) is present, it is ignored.

  • Type: object
  • Required: Yes

material.emissiveFactor

The RGB components of the emissive color of the material. If an emissiveTexture is specified, this value is multiplied with the texel values.

  • Type: number[3]
    • Each element in the array must be greater than or equal to 0 and less than or equal to 1.
  • Required: No, default: [0,0,0]

material.alphaMode

The material's alpha rendering mode enumeration specifying the interpretation of the alpha value of the main factor and texture. If the alpha mode is not specified, it defaults to OPAQUE where the alpha value is ignored and the rendered output is fully opaque. In MASK mode, the rendered output is either fully opaque or fully transparent depending on the alpha value and the specified alpha cutoff value. In BLEND mode, the alpha value is used to composite the source and destination areas. The rendered output is combined with the background using the normal painting operation (i.e. the Porter and Duff over operator).

  • Type: string
  • Required: No, default: "OPAQUE"
  • Allowed values: "OPAQUE (In OPAQUE mode, the alpha value is ignored and the rendered output is fully opaque.)", "MASK (In MASK mode, the rendered output is either fully opaque or fully transparent depending on the alpha value and the specified alpha cutoff value.)", "BLEND (In BLEND mode, the alpha value is used to composite the source and destination areas. The rendered output is combined with the background using the normal painting operation (i.e. the Porter and Duff over operator).)"

material.alphaCutoff

Specifies the cutoff threshold when in MASK mode. If the alpha value is greater than or equal to this value then it is rendered as fully opaque, otherwise, it is rendered as fully transparent. This value is ignored for other modes.

  • Type: number
  • Required: No, default: 0.5
  • Minimum: >= 0

material.doubleSided

Specifies whether the material is double sided. When this value is false, back-face culling is enabled. When this value is true, back-face culling is disabled and double sided lighting is enabled. The back-face must have its normals reversed before the lighting equation is evaluated.

  • Type: boolean
  • Required: No, default: false

mesh

A set of primitives to be rendered. A node can contain one or more meshes. A node's transform places the mesh in the scene.

Properties

Type Description Required
primitives primitive[1-*] An array of primitives, each defining geometry to be rendered with a material. ✅ Yes
name string The user-defined name of this object. No
extensions object Dictionary object with extension-specific objects. No
extras any Application-specific data. No
weights number[0-*] Array of weights to be applied to the Morph Targets. No

Additional properties are allowed.

mesh.primitives ✅

An array of primitives, each defining geometry to be rendered with a material.

mesh.name

The user-defined name of this object. This is not necessarily unique, e.g., an accessor and a buffer could have the same name, or two accessors could even have the same name.

  • Type: string
  • Required: No

mesh.extensions

Dictionary object with extension-specific objects.

  • Type: object
  • Required: No
  • Type of each property: extension

mesh.extras

Application-specific data.

  • Type: any
  • Required: No

mesh.weights

Array of weights to be applied to the Morph Targets.

  • Type: number[0-*]
  • Required: No

node

A node in the node hierarchy. When the node contains skin, all mesh.primitives must contain JOINT and WEIGHT attributes. A node can have either a matrix or any combination of translation/rotation/scale (TRS) properties. TRS properties are converted to matrices and postmultiplied in the T * R * S order to compose the transformation matrix; first the scale is applied to the vertices, then the rotation, and then the translation. If none are provided, the transform is the identity. When a node is targeted for animation (referenced by an animation.channel.target), only TRS properties may be present; matrix will not be present.

Properties

Type Description Required
camera integer The index of the camera referenced by this node. No
children integer[] The indices of this node's children. No, default: []
skin integer The index of the skin referenced by this node. No
matrix number[16] A floating-point 4x4 transformation matrix stored in column-major order. No, default: [1,0,0,0,0,1,0,0,0,0,1,0,0,0,0,1]
mesh integer The index of the mesh in this node. No
rotation number[4] The node's unit quaternion rotation in the order (x, y, z, w), where w is the scalar. No, default: [0,0,0,1]
scale number[3] The node's non-uniform scale. No, default: [1,1,1]
translation number[3] The node's translation. No, default: [0,0,0]
weights number[1-*] The weights of the instantiated Morph Target. Number of elements must match number of Morph Targets of used mesh. No
name string The user-defined name of this object. No
extensions object Dictionary object with extension-specific objects. No
extras any Application-specific data. No

Additional properties are allowed.

node.camera

The index of the camera referenced by this node.

  • Type: integer
  • Required: No
  • Minimum: >= 0

node.children

The indices of this node's children.

  • Type: integer[]
    • Each element in the array must be unique.
    • Each element in the array must be greater than or equal to 0.
  • Required: No, default: []

node.skin

The index of the skin referenced by this node.

  • Type: integer
  • Required: No
  • Minimum: >= 0

node.matrix

A floating-point 4x4 transformation matrix stored in column-major order.

  • Type: number[16]
  • Required: No, default: [1,0,0,0,0,1,0,0,0,0,1,0,0,0,0,1]
  • Related WebGL functions: uniformMatrix4fv() with the transpose parameter equal to false

node.mesh

The index of the mesh in this node.

  • Type: integer
  • Required: No
  • Minimum: >= 0

node.rotation

The node's unit quaternion rotation in the order (x, y, z, w), where w is the scalar.

  • Type: number[4]
  • Required: No, default: [0,0,0,1]

node.scale

The node's non-uniform scale.

  • Type: number[3]
  • Required: No, default: [1,1,1]

node.translation

The node's translation.

  • Type: number[3]
  • Required: No, default: [0,0,0]

node.weights

The weights of the instantiated Morph Target. Number of elements must match number of Morph Targets of used mesh.

  • Type: number[1-*]
    • Each element in the array must be greater than or equal to 0.
  • Required: No

node.name

The user-defined name of this object. This is not necessarily unique, e.g., an accessor and a buffer could have the same name, or two accessors could even have the same name.

  • Type: string
  • Required: No

node.extensions

Dictionary object with extension-specific objects.

  • Type: object
  • Required: No
  • Type of each property: extension

node.extras

Application-specific data.

  • Type: any
  • Required: No

normalTextureInfo

Reference to a texture.

Properties

Type Description Required
index integer The index of the texture. ✅ Yes
texCoord integer The set index of texture's TEXCOORD attribute used for texture coordinate mapping. No, default: 0
scale number The scalar multiplier applied to each normal vector of the normal texture. No, default: 1

Additional properties are allowed.

normalTextureInfo.index ✅

The index of the texture.

  • Type: integer
  • Required: Yes
  • Minimum: >= 0

normalTextureInfo.texCoord

This integer value is used to construct a string in the format TEXCOORD_ which is a reference to a key in mesh.primitives.attributes (e.g. A value of 0 corresponds to TEXCOORD_0).

  • Type: integer
  • Required: No, default: 0
  • Minimum: >= 0

normalTextureInfo.scale

The scalar multiplier applied to each normal vector of the texture. This value scales the normal vector using the formula: scaledNormal = normalize((normalize(<sampled normal texture value>) * 2.0 - 1.0) * vec3(<normal scale>, <normal scale>, 1.0)). This value is ignored if normalTexture is not specified. This value is linear.

  • Type: number
  • Required: No, default: 1

occlusionTextureInfo

Reference to a texture.

Properties

Type Description Required
index integer The index of the texture. ✅ Yes
texCoord integer The set index of texture's TEXCOORD attribute used for texture coordinate mapping. No, default: 0
strength number A scalar multiplier controlling the amount of occlusion applied. No, default: 1

Additional properties are allowed.

occlusionTextureInfo.index ✅

The index of the texture.

  • Type: integer
  • Required: Yes
  • Minimum: >= 0

occlusionTextureInfo.texCoord

This integer value is used to construct a string in the format TEXCOORD_ which is a reference to a key in mesh.primitives.attributes (e.g. A value of 0 corresponds to TEXCOORD_0).

  • Type: integer
  • Required: No, default: 0
  • Minimum: >= 0

occlusionTextureInfo.strength

A scalar multiplier controlling the amount of occlusion applied. A value of 0.0 means no occlusion. A value of 1.0 means full occlusion. This value affects the resulting color using the formula: occludedColor = lerp(color, color * <sampled occlusion [texture](#reference-texture) value>, <occlusion strength>). This value is ignored if the corresponding texture is not specified. This value is linear.

  • Type: number
  • Required: No, default: 1
  • Minimum: >= 0
  • Maximum: <= 1

orthographic

An orthographic camera containing properties to create an orthographic projection matrix.

Properties

Type Description Required
xmag number The floating-point horizontal magnification of the view. ✅ Yes
ymag number The floating-point vertical magnification of the view. ✅ Yes
zfar number The floating-point distance to the far clipping plane. ✅ Yes
znear number The floating-point distance to the near clipping plane. ✅ Yes
extensions object Dictionary object with extension-specific objects. No
extras any Application-specific data. No

Additional properties are allowed.

orthographic.xmag ✅

The floating-point horizontal magnification of the view.

  • Type: number
  • Required: Yes

orthographic.ymag ✅

The floating-point vertical magnification of the view.

  • Type: number
  • Required: Yes

orthographic.zfar ✅

The floating-point distance to the far clipping plane.

  • Type: number
  • Required: Yes
  • Minimum: >= 0

orthographic.znear ✅

The floating-point distance to the near clipping plane.

  • Type: number
  • Required: Yes
  • Minimum: >= 0

orthographic.extensions

Dictionary object with extension-specific objects.

  • Type: object
  • Required: No
  • Type of each property: extension

orthographic.extras

Application-specific data.

  • Type: any
  • Required: No

pbrMetallicRoughness

A set of parameter values that are used to define the metallic-roughness material model from Physically-Based Rendering (PBR) methodology.

Properties

Type Description Required
baseColorFactor number[4] The material's base color factor. No, default: [1,1,1,1]
baseColorTexture object The base color texture. ✅ Yes
metallicFactor number The metalness of the material. No, default: 1
roughnessFactor number The roughness of the material. No, default: 1
metallicRoughnessTexture object The metallic-roughness texture. ✅ Yes

Additional properties are allowed.

pbrMetallicRoughness.baseColorFactor

The RGBA components of the base color of the material. The fourth component (A) is the alpha coverage of the material. The alphaMode property specifies how alpha is interpreted. These values are linear.

  • Type: number[4]
    • Each element in the array must be greater than or equal to 0 and less than or equal to 1.
  • Required: No, default: [1,1,1,1]

pbrMetallicRoughness.baseColorTexture ✅

The base color texture. This texture contains RGB(A) components in sRGB color space. The first three components (RGB) specify the base color of the material. If the fourth component (A) is present, it represents the alpha coverage of the material. Otherwise, an alpha of 1.0 is assumed. The alphaMode property specifies how alpha is interpreted. The stored texels must not be premultiplied.

  • Type: object
  • Required: Yes

pbrMetallicRoughness.metallicFactor

The metalness of the material. A value of 1.0 means the material is a metal. A value of 0.0 means the material is a dielectric. Values in between are for blending between metals and dielectrics such as dirty metallic surfaces. This value is linear.

  • Type: number
  • Required: No, default: 1
  • Minimum: >= 0
  • Maximum: <= 1

pbrMetallicRoughness.roughnessFactor

The roughness of the material. A value of 1.0 means the material is completely rough. A value of 0.0 means the material is completely smooth. This value is linear.

  • Type: number
  • Required: No, default: 1
  • Minimum: >= 0
  • Maximum: <= 1

pbrMetallicRoughness.metallicRoughnessTexture ✅

The metallic-roughness texture. The metalness values are sampled from the B channel. The roughness values are sampled from the G channel. These values are linear. If other channels are present (R or A), they are ignored for metallic-roughness calculations.

  • Type: object
  • Required: Yes

perspective

A perspective camera containing properties to create a perspective projection matrix.

Properties

Type Description Required
aspectRatio number The floating-point aspect ratio of the field of view. No
yfov number The floating-point vertical field of view in radians. ✅ Yes
zfar number The floating-point distance to the far clipping plane. No
znear number The floating-point distance to the near clipping plane. ✅ Yes
extensions object Dictionary object with extension-specific objects. No
extras any Application-specific data. No

Additional properties are allowed.

perspective.aspectRatio

The floating-point aspect ratio of the field of view. When this is undefined, the aspect ratio of the canvas is used.

  • Type: number
  • Required: No
  • Minimum: > 0

perspective.yfov ✅

The floating-point vertical field of view in radians.

  • Type: number
  • Required: Yes
  • Minimum: > 0

perspective.zfar

The floating-point distance to the far clipping plane. When defined, zfar must be greater than znear. If zfar is undefined, runtime must use infinite projection matrix.

  • Type: number
  • Required: No
  • Minimum: > 0

perspective.znear ✅

The floating-point distance to the near clipping plane.

  • Type: number
  • Required: Yes
  • Minimum: > 0

perspective.extensions

Dictionary object with extension-specific objects.

  • Type: object
  • Required: No
  • Type of each property: extension

perspective.extras

Application-specific data.

  • Type: any
  • Required: No

primitive

Geometry to be rendered with the given material.

Related WebGL functions: drawElements() and drawArrays()

Properties

Type Description Required
attributes object A dictionary object, where each key corresponds to mesh attribute semantic and each value is the index of the accessor containing attribute's data. ✅ Yes
indices integer The index of the accessor that contains the indices. No
material integer The index of the material to apply to this primitive when rendering. No
mode integer The type of primitives to render. No, default: 4
targets integer[0-*] An array of Morph Targets, each Morph Target is a dictionary mapping attributes (only "POSITION" and "NORMAL" supported) to their deviations in the Morph Target. No
extensions object Dictionary object with extension-specific objects. No
extras any Application-specific data. No

Additional properties are allowed.

primitive.attributes ✅

A dictionary object, where each key corresponds to mesh attribute semantic and each value is the index of the accessor containing attribute's data.

  • Type: object
  • Required: Yes
  • Type of each property: integer

primitive.indices

The index of the accessor that contains mesh indices. When this is not defined, the primitives should be rendered without indices using drawArrays(). When defined, the accessor must contain indices: the bufferView referenced by the accessor must have a target equal to 34963 (ELEMENT_ARRAY_BUFFER); a byteStride that is tightly packed, i.e., 0 or the byte size of componentType in bytes; componentType must be 5121 (UNSIGNED_BYTE), 5123 (UNSIGNED_SHORT) or 5125 (UNSIGNED_INT), the latter is only allowed when OES_element_index_uint extension is used; type must be "SCALAR".

  • Type: integer
  • Required: No
  • Minimum: >= 0

primitive.material

The index of the material to apply to this primitive when rendering.

  • Type: integer
  • Required: No
  • Minimum: >= 0

primitive.mode

The type of primitives to render. All valid values correspond to WebGL enums.

  • Type: integer
  • Required: No, default: 4
  • Allowed values: 0 (POINTS), 1 (LINES), 2 (LINE_LOOP), 3 (LINE_STRIP), 4 (TRIANGLES), 5 (TRIANGLE_STRIP), 6 (TRIANGLE_FAN)

primitive.targets

An array of Morph Targets, each Morph Target is a dictionary mapping attributes (only "POSITION" and "NORMAL" supported) to their deviations in the Morph Target.

  • Type: integer[0-*]
    • Each element in the array must be greater than or equal to 0.
  • Required: No

primitive.extensions

Dictionary object with extension-specific objects.

  • Type: object
  • Required: No
  • Type of each property: extension

primitive.extras

Application-specific data.

  • Type: any
  • Required: No

sampler

Texture sampler properties for filtering and wrapping modes.

Related WebGL functions: texParameterf()

Properties

Type Description Required
magFilter integer Magnification filter. No
minFilter integer Minification filter. No
wrapS integer s wrapping mode. No, default: 10497
wrapT integer t wrapping mode. No, default: 10497
name string The user-defined name of this object. No
extensions object Dictionary object with extension-specific objects. No
extras any Application-specific data. No

Additional properties are allowed.

sampler.magFilter

Magnification filter. Valid values correspond to WebGL enums: 9728 (NEAREST) and 9729 (LINEAR).

  • Type: integer
  • Required: No
  • Allowed values: 9728 (NEAREST), 9729 (LINEAR)
  • Related WebGL functions: texParameterf() with pname equal to TEXTURE_MAG_FILTER

sampler.minFilter

Minification filter. All valid values correspond to WebGL enums.

  • Type: integer
  • Required: No
  • Allowed values: 9728 (NEAREST), 9729 (LINEAR), 9984 (NEAREST_MIPMAP_NEAREST), 9985 (LINEAR_MIPMAP_NEAREST), 9986 (NEAREST_MIPMAP_LINEAR), 9987 (LINEAR_MIPMAP_LINEAR)
  • Related WebGL functions: texParameterf() with pname equal to TEXTURE_MIN_FILTER

sampler.wrapS

s wrapping mode. All valid values correspond to WebGL enums.

  • Type: integer
  • Required: No, default: 10497
  • Allowed values: 33071 (CLAMP_TO_EDGE), 33648 (MIRRORED_REPEAT), 10497 (REPEAT)
  • Related WebGL functions: texParameterf() with pname equal to TEXTURE_WRAP_S

sampler.wrapT

t wrapping mode. All valid values correspond to WebGL enums.

  • Type: integer
  • Required: No, default: 10497
  • Allowed values: 33071 (CLAMP_TO_EDGE), 33648 (MIRRORED_REPEAT), 10497 (REPEAT)
  • Related WebGL functions: texParameterf() with pname equal to TEXTURE_WRAP_T

sampler.name

The user-defined name of this object. This is not necessarily unique, e.g., an accessor and a buffer could have the same name, or two accessors could even have the same name.

  • Type: string
  • Required: No

sampler.extensions

Dictionary object with extension-specific objects.

  • Type: object
  • Required: No
  • Type of each property: extension

sampler.extras

Application-specific data.

  • Type: any
  • Required: No

scene

The root nodes of a scene.

Properties

Type Description Required
nodes integer[] The indices of each root node. No, default: []
name string The user-defined name of this object. No
extensions object Dictionary object with extension-specific objects. No
extras any Application-specific data. No

Additional properties are allowed.

scene.nodes

The indices of each root node.

  • Type: integer[]
    • Each element in the array must be unique.
    • Each element in the array must be greater than or equal to 0.
  • Required: No, default: []

scene.name

The user-defined name of this object. This is not necessarily unique, e.g., an accessor and a buffer could have the same name, or two accessors could even have the same name.

  • Type: string
  • Required: No

scene.extensions

Dictionary object with extension-specific objects.

  • Type: object
  • Required: No
  • Type of each property: extension

scene.extras

Application-specific data.

  • Type: any
  • Required: No

skin

Joints and matrices defining a skin.

Properties

Type Description Required
inverseBindMatrices integer The index of the accessor containing the floating-point 4x4 inverse-bind matrices. The default is that each matrix is a 4x4 identity matrix, which implies that inverse-bind matrices were pre-applied. No
skeleton integer The index of the node used as a skeleton root. When undefined, joints transforms resolve to scene root. No
joints integer[] Indices of skeleton nodes, used as joints in this skin. ✅ Yes
name string The user-defined name of this object. No
extensions object Dictionary object with extension-specific objects. No
extras any Application-specific data. No

Additional properties are allowed.

skin.inverseBindMatrices

The index of the accessor containing the floating-point 4x4 inverse-bind matrices. The default is that each matrix is a 4x4 identity matrix, which implies that inverse-bind matrices were pre-applied.

  • Type: integer
  • Required: No
  • Minimum: >= 0

skin.skeleton

The index of the node used as a skeleton root. When undefined, joints transforms resolve to scene root.

  • Type: integer
  • Required: No
  • Minimum: >= 0

skin.joints ✅

Indices of skeleton nodes, used as joints in this skin. The array length must be the same as the count property of the inverseBindMatrices accessor (when defined).

  • Type: integer[]
    • Each element in the array must be unique.
    • Each element in the array must be greater than or equal to 0.
  • Required: Yes

skin.name

The user-defined name of this object. This is not necessarily unique, e.g., an accessor and a buffer could have the same name, or two accessors could even have the same name.

  • Type: string
  • Required: No

skin.extensions

Dictionary object with extension-specific objects.

  • Type: object
  • Required: No
  • Type of each property: extension

skin.extras

Application-specific data.

  • Type: any
  • Required: No

sparse

Sparse storage of attributes that deviate from their initialization value.

Properties

Type Description Required
count integer Number of entries stored in the sparse array. ✅ Yes
indices object Index array of size count that points to those accessor attributes that deviate from their initialization value. Indices must strictly increase. ✅ Yes
values object Array of size count times number of components, storing the displaced accessor attributes pointed by indices. Substituted values must have the same componentType and number of components as the base accessor. ✅ Yes
extensions object Dictionary object with extension-specific objects. No
extras any Application-specific data. No

Additional properties are allowed.

sparse.count ✅

The number of attributes encoded in this sparse accessor.

  • Type: integer
  • Required: Yes
  • Minimum: >= 1

sparse.indices ✅

Index array of size count that points to those accessor attributes that deviate from their initialization value. Indices must strictly increase.

  • Type: object
  • Required: Yes

sparse.values ✅

Array of size count times number of components, storing the displaced accessor attributes pointed by indices. Substituted values must have the same componentType and number of components as the base accessor.

  • Type: object
  • Required: Yes

sparse.extensions

Dictionary object with extension-specific objects.

  • Type: object
  • Required: No
  • Type of each property: extension

sparse.extras

Application-specific data.

  • Type: any
  • Required: No

target

A dictionary object specifying attributes displacements in a Morph Target, where each key corresponds to one of the two supported attribute semantic ("POSITION" or "NORMAL") and each value is the index of the accessor containing the attribute displacements' data.

texture

A texture and its sampler.

Related WebGL functions: createTexture(), deleteTexture(), bindTexture(), texImage2D(), and texParameterf()

Properties

Type Description Required
sampler integer The index of the sampler used by this texture. When undefined, a sampler with repeat wrapping and auto filtering should be used. No
source integer The index of the image used by this texture. When undefined, a default texture should be used. No
name string The user-defined name of this object. No
extensions object Dictionary object with extension-specific objects. No
extras any Application-specific data. No

Additional properties are allowed.

texture.sampler

The index of the sampler used by this texture. When undefined, a sampler with repeat wrapping and auto filtering should be used.

  • Type: integer
  • Required: No
  • Minimum: >= 0

texture.source

The index of the image used by this texture. When undefined, a default texture should be used.

  • Type: integer
  • Required: No
  • Minimum: >= 0

texture.name

The user-defined name of this object. This is not necessarily unique, e.g., an accessor and a buffer could have the same name, or two accessors could even have the same name.

  • Type: string
  • Required: No

texture.extensions

Dictionary object with extension-specific objects.

  • Type: object
  • Required: No
  • Type of each property: extension

texture.extras

Application-specific data.

  • Type: any
  • Required: No

textureInfo

Reference to a texture.

Properties

Type Description Required
index integer The index of the texture. ✅ Yes
texCoord integer The set index of texture's TEXCOORD attribute used for texture coordinate mapping. No, default: 0

Additional properties are allowed.

textureInfo.index ✅

The index of the texture.

  • Type: integer
  • Required: Yes
  • Minimum: >= 0

textureInfo.texCoord

This integer value is used to construct a string in the format TEXCOORD_ which is a reference to a key in mesh.primitives.attributes (e.g. A value of 0 corresponds to TEXCOORD_0).

  • Type: integer
  • Required: No, default: 0
  • Minimum: >= 0

values

Array of size accessor.sparse.count times number of components storing the displaced accessor attributes pointed by accessor.sparse.indices.

Properties

Type Description Required
bufferView integer The index of the bufferView with sparse values. Referenced bufferView can't have ARRAY_BUFFER or ELEMENT_ARRAY_BUFFER target. ✅ Yes
byteOffset integer The offset relative to the start of the bufferView in bytes. Must be aligned. No, default: 0
extensions object Dictionary object with extension-specific objects. No
extras any Application-specific data. No

Additional properties are allowed.

values.bufferView ✅

The index of the bufferView with sparse values. Referenced bufferView can't have ARRAY_BUFFER or ELEMENT_ARRAY_BUFFER target.

  • Type: integer
  • Required: Yes
  • Minimum: >= 0

values.byteOffset

The offset relative to the start of the bufferView in bytes. Must be aligned.

  • Type: integer
  • Required: No, default: 0
  • Minimum: >= 0

values.extensions

Dictionary object with extension-specific objects.

  • Type: object
  • Required: No
  • Type of each property: extension

values.extras

Application-specific data.

  • Type: any
  • Required: No
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