Returns the number of materials in an sfmesh object.
Syntax
int4 ST_NumMaterials(sfmesh sfmeshObject);Parameters
| Parameter | Description |
|---|---|
sfmeshObject | The sfmesh object to query. |
Description
ST_NumMaterials counts the entries in the materials array of an sfmesh object and returns the count as an integer.
Example
The following example queries an sfmesh object that has one material entry. The sfmesh object is constructed inline using a JSON literal cast to the sfmesh type.
SELECT ST_NumMaterials('{
"meshgeoms": ["MESHGEOM(PATCH(TRIANGLESTRIP(0 0,0 10,10 10,10 0)))"],
"materials": [{"type": "db", "attributes": {"schema": "public", "table": "t_material", "column": "the_material", "key": "num=1"}}],
"primitives": [{"meshgeom": 0, "material": 0}],
"nodes": [{"primitive": 0}]
}'::sfmesh);
-- Result: 1 (the materials array contains one entry)