VertexFormat

A vertex format is a descriptor that defines the layout of vertex data inside a VertexBuffer.

// Specify 3-component positions (x, y, z)
const vertexFormat = new pc.VertexFormat(graphicsDevice, [
    { semantic: pc.SEMANTIC_POSITION, components: 3, type: pc.TYPE_FLOAT32 }
]);

// Specify 2-component positions (x, y), a texture coordinate (u, v) and a vertex color (r, g, b, a)
const vertexFormat = new pc.VertexFormat(graphicsDevice, [
    { semantic: pc.SEMANTIC_POSITION, components: 2, type: pc.TYPE_FLOAT32 },
    { semantic: pc.SEMANTIC_TEXCOORD0, components: 2, type: pc.TYPE_FLOAT32 },
    { semantic: pc.SEMANTIC_COLOR, components: 4, type: pc.TYPE_UINT8, normalize: true }
]);

Summary

Static Methods

getDefaultInstancingFormat

The VertexFormat used to store matrices of type Mat4 for hardware instancing.

Properties

elements	The vertex attribute elements.
elements[].dataType	The data type of the attribute.
elements[].name	The meaning of the vertex element.
elements[].normalize	If true, vertex attribute data will be mapped from a 0 to 255 range down to 0 to 1 when fed to a shader.
elements[].numComponents	The number of components of the vertex attribute.
elements[].offset	The number of initial bytes at the start of a vertex that are not relevant to this attribute.
elements[].size	The size of the attribute in bytes.
elements[].stride	The number of total bytes that are between the start of one vertex, and the start of the next.

Details

Static Methods

getDefaultInstancingFormat(graphicsDevice) 

The VertexFormat used to store matrices of type Mat4 for hardware instancing.

Parameters

graphicsDevice

GraphicsDevice

The graphics device used to create this vertex format.

Returns

VertexFormat

The default instancing vertex format.

Constructor

VertexFormat(graphicsDevice, description, [vertexCount]) 

Create a new VertexFormat instance.

// Specify 3-component positions (x, y, z)
const vertexFormat = new pc.VertexFormat(graphicsDevice, [
    { semantic: pc.SEMANTIC_POSITION, components: 3, type: pc.TYPE_FLOAT32 }
]);

// Specify 2-component positions (x, y), a texture coordinate (u, v) and a vertex color (r, g, b, a)
const vertexFormat = new pc.VertexFormat(graphicsDevice, [
    { semantic: pc.SEMANTIC_POSITION, components: 2, type: pc.TYPE_FLOAT32 },
    { semantic: pc.SEMANTIC_TEXCOORD0, components: 2, type: pc.TYPE_FLOAT32 },
    { semantic: pc.SEMANTIC_COLOR, components: 4, type: pc.TYPE_UINT8, normalize: true }
]);

Parameters

graphicsDevice	GraphicsDevice	The graphics device used to manage this vertex format.
description	object[]	An array of vertex attribute descriptions.
description[].semantic	string	The meaning of the vertex element. This is used to link the vertex data to a shader input. Can be: SEMANTIC_POSITION SEMANTIC_NORMAL SEMANTIC_TANGENT SEMANTIC_BLENDWEIGHT SEMANTIC_BLENDINDICES SEMANTIC_COLOR SEMANTIC_TEXCOORD0 SEMANTIC_TEXCOORD1 SEMANTIC_TEXCOORD2 SEMANTIC_TEXCOORD3 SEMANTIC_TEXCOORD4 SEMANTIC_TEXCOORD5 SEMANTIC_TEXCOORD6 SEMANTIC_TEXCOORD7 If vertex data has a meaning other that one of those listed above, use the user-defined semantics: SEMANTIC_ATTR0 to SEMANTIC_ATTR15.
description[].components	number	The number of components of the vertex attribute. Can be 1, 2, 3 or 4.
description[].type	number	The data type of the attribute. Can be: TYPE_INT8 TYPE_UINT8 TYPE_INT16 TYPE_UINT16 TYPE_INT32 TYPE_UINT32 TYPE_FLOAT32
description[].normalize	boolean	If true, vertex attribute data will be mapped from a 0 to 255 range down to 0 to 1 when fed to a shader. If false, vertex attribute data is left unchanged. If this property is unspecified, false is assumed.
vertexCount	number	When specified, vertex format will be set up for non-interleaved format with a specified number of vertices. (example: PPPPNNNNCCCC), where arrays of individual attributes will be stored one right after the other (subject to alignment requirements). Note that in this case, the format depends on the number of vertices, and needs to change when the number of vertices changes. When not specified, vertex format will be interleaved. (example: PNCPNCPNCPNC).

Properties

object[]elements 

The vertex attribute elements.

numberelements[].dataType 

The data type of the attribute. Can be:

stringelements[].name 

The meaning of the vertex element. This is used to link the vertex data to a shader input. Can be:

If vertex data has a meaning other that one of those listed above, use the user-defined semantics: SEMANTIC_ATTR0 to SEMANTIC_ATTR15.

booleanelements[].normalize 

If true, vertex attribute data will be mapped from a 0 to 255 range down to 0 to 1 when fed to a shader. If false, vertex attribute data is left unchanged. If this property is unspecified, false is assumed.

numberelements[].numComponents 

The number of components of the vertex attribute. Can be 1, 2, 3 or 4.

numberelements[].offset 

The number of initial bytes at the start of a vertex that are not relevant to this attribute.

numberelements[].size 

The size of the attribute in bytes.

numberelements[].stride 

The number of total bytes that are between the start of one vertex, and the start of the next.