ST_MakeMaterial-PolarDB(PolarDB)-阿里云帮助中心

Creates a material object for use in 3D spatial data.

Syntax

Syntax 1 — Define a material using Open Computing Language (OpenCL) color attributes:

material ST_MakeMaterial(cstring ambient default NULL,
                         cstring diffuse default NULL,
                         cstring specular default NULL,
                         integer shininess default NULL,
                         integer transparency default NULL,
                         integer texture_index default NULL)

Syntax 2 — Reference a material stored in another table:

material ST_MakeMaterial(text table_name,
                         text column_name,
                         text key_value,
                         text schema_name default NULL)

Syntax 3 — Define a material using a PBR JSON string in GL Transmission Format (glTF):

material ST_MakeMaterial(cstring attributes,
                         texture[] textures default NULL)

Description

ST_MakeMaterial returns a material object. Choose the syntax based on how you want to define the material:

Syntax 1 describes the material using OpenCL color attributes (ambient, diffuse, specular, shininess, transparency). The function converts the OpenCL-style description to a JSON-formatted output.
Syntax 2 references a material stored in another table. This approach reduces the amount of mesh data and makes it easier to update materials in one place.
Syntax 3 accepts a PBR material description in glTF format as a JSON string, with an optional array of textures.

Parameters

Syntax 1

Parameter	Type	Description
`ambient`	cstring	The ambient light color, as an RGBA hexadecimal string. Example: `#FF88FF00`.
`diffuse`	cstring	The diffuse color, as an RGBA hexadecimal string. Example: `#FF88FF00`.
`specular`	cstring	The specular color, as an RGBA hexadecimal string. Example: `#FF88FF00`.
`shininess`	integer	The glossiness. Valid values: 0 to 100.
`transparency`	integer	The transparency. Valid values: 0 to 100.
`texture_index`	integer	The index of the texture to which the material belongs. Valid values: 0 to 32767.

Syntax 2

Parameter	Type	Description
`table_name`	text	The name of the table that contains the existing material.
`column_name`	text	The name of the column that contains the existing material.
`key_value`	text	The ID of the existing material, used in the WHERE clause.
`schema_name`	text	The schema of the table. Defaults to the schema of the table specified in the search path.

Syntax 3

Parameter	Type	Description
`attributes`	cstring	A PBR material description in glTF format, as a JSON string.
`textures`	texture[]	The array of textures included in the material.

Examples

Syntax 1 — OpenCL color attributes

Specify all color attributes and a texture index:

SELECT ST_AsText(ST_MakeMaterial('#FFDDEEAA', '#FFDDEEAA', '#FFDDEEAA', 30, 70, 2));

Output:

{"type":"raw", "attributes": {"ambient":"#FFDDEEAA","diffuse":"#FFDDEEAA","specular":"#FFDDEEAA","shininess":30,"transparency":70,"texture":2}}

Specify only the diffuse color using a named parameter:

SELECT ST_AsText(ST_MakeMaterial(diffuse => '#FFDDEEAA'));

Output:

{"type":"raw", "attributes": {"diffuse":"#FFDDEEAA"}}

Syntax 2 — Reference an existing material

Reference a material stored in the t_material table:

SELECT ST_AsText(ST_MakeMaterial('t_material'::text,
                                 'the_material'::text,
                                 'num=1'::text));

Output:

{"type":"db", "attributes": {"schema":"public","table":"t_material","column":"the_material","key":"num=1"}}

Syntax 3 — PBR JSON string with textures

Define a material using a PBR JSON string and include textures from a table:

SELECT ST_AsText(ST_MakeMaterial(
    '{"pbrMetallicRoughness": {"baseColorFactor": [ 1.000, 0.766, 0.336, 1.0 ], "metallicFactor": 0.5,"roughnessFactor": 0.1}}',
    ARRAY(SELECT the_texture FROM t_texture)));

Output:

{"type":"raw", "textures":[{"compressionType" : "None", "format" : "JPEG", "wrap" : "Wrap", "type" : "Raw", "depth" : 3, "width" : 256, "height" : 256, "size" : 6, "data" : "313233343536"}], "attributes": {"pbrMetallicRoughness":{"baseColorFactor":[1.0,0.766,0.336,1.0],"metallicFactor":0.5,"roughnessFactor":0.1}}}