Qt3D Core

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Qt3D Core

Core elements

The Core exposes a few default elements that make up all Qt3D scenes.

Node

A base Qt3D element.

Entity

An Entity is a Node which has a list of Component properties. This is the type of elements that are actually rendered.

Component

Components are elements that are used to further specify an Entity.

Custom elements

Custom elements can be created by subclassing an Entity and predefining a set of properties.

===== * Camera
The Camera elements is an Entity that contains a Transform and a CameraLens.

Camera {<br /> id : camera2 =====

lens : CameraLens {<br /> projectionType: CameraLens.PerspectiveProjection<br /> fieldOfView: 45<br /> aspectRatio: 16/9<br /> nearPlane : 0.01<br /> farPlane : 1000.0<br /> }

transform : Transform {<br /> LookAt {<br /> position: Qt.vector3d( 0.0, –1.0, –5.0 )<br /> upVector: Qt.vector3d( 0.0, 1.0, 0.0 )<br /> viewCenter: Qt.vector3d( 0.0, 2.0, 10.0 )<br /> }<br /> Rotate {<br /> axis : Qt.vector3d(0, 0, 1)<br /> angle : 40<br /> }<br /> }<br /> }

Resources Management

To achieve high rendering performances, the memory access to the resources has to be properly managed and structured. Therefore, a set of templated resources management oriented classes have been developed in the core of Qt3D.

• QHandle
• QArrayResourcesManager
• QListResourcesManager

The use of a Handle systems allows for resources to be easily accessed and managed while allowing for memory structure to be realigned so as to maintain a contiguous memory alignment and reduce fragmentation.
This should lower the amount of cache misses and speed up rendering.

Other Resources management oriented classes include :
* QCircularBuffer