- Qt 6.8
- Qt Quick 3D
- QML Types
- FileInstancing
- Qt Quick 3D | Commercial or GPLv3

# FileInstancing QML Type

Allows reading instance tables from file. More...

Import Statement: | `import QtQuick3D`
Since: | Qt 6.2
Inherits: | Instancing

- List of all members, including inherited members

## Properties

- instanceCount : int `(since 6.3)`
- source : url

## Detailed Description

The FileInstancing type makes it possible to read instance tables from files.

There are two supported file formats: XML, and a Qt-specific binary format. The binary file format uses the same layout as the table that is uploaded to the GPU, so it can be directly mapped to memory. The instancer tool converts from XML to the binary format.

This is an example of the XML file format:

     <?xml version="1.0" encoding="UTF-8" ?>
     <InstanceTable>
       <Instance position="0 200 0"  scale="0.75 0.75 0.75" custom="20 20" color="#ffcf7f"/>
       <Instance position="0 -100 0" scale="0.5 0.5 0.5" color="red"/>
       <Instance position="0 -200 0" eulerRotation="0 0 60" color="darkred" custom="10 40 0 0"/>
     </InstanceTable>

In order to be valid, the XML file must have a top-level `InstanceTable` element. Each instance is represented by an `Instance` element inside the `InstanceTable`. Unknown elements are silently ignored.

An `Instance` element can have a number of attributes. `color` attributes are specified by the normal Qt SVG color names, or by hexadecimal notation. `vector3d` and {vector4d} attributes are specified by a string of space-separated numbers, where missing trailing numbers indicate zeroes. The following attributes are supported:

name | type
--- | ---
`position` | `vector3d`
`scale` | `vector3d`
`eulerRotation` | `vector3d`
`quaternion` | `vector4d`
`custom` | `vector4d`
`color` | `color`

Unknown attributes are silently ignored.

## Property Documentation

instanceCount : int `[since 6.3]`

This read-only property contains the number of instances in the instance table.

This property was introduced in Qt 6.3.

source : url

This property holds the location of an XML or binary file containing the instance data.

If the file name has a ".bin" extension, it is assumed to refer to a binary file. Otherwise it is assumed to refer to an XML file. If an XML file foo.xml is specified, and the file foo.xml.bin exists, the binary file foo.xml.bin will be loaded instead.