View3D QML Type

Provides a viewport on which to render a 3D scene. 更多...

导入语句: import QtQuick3D 1.15

特性

方法

详细描述

View3D provides a 2D surface for 3D content to be rendered to. Before 3D content can be displayed in a Qt Quick scene, it must first be flattend.

There are two ways to define a 3D scene for View3D to view. The first and easiest is to just define a higharchy of Node based items as children of the View3D. This becomes the implicit scene of the viewport.

It is also possible to reference an existing scene by using the importScene property of the scene you want to render. This scene does not have to exist as a child of the current View3D.

There is also a combination approach where you define both a scene with children nodes, as well as define a scene that is being referenced. In this case you can treat the referenced scene as a sibling of the child scene.

This is demonstrated in View3D example

To control how a scene is rendered, it is necessary to define a SceneEnvironment environment 特性。

To project a 3D scene to a 2D viewport, it is necessary to view the scene from a camera. If a scene has more than one camera it is possible to set which camera is used to render the scene to this viewport by setting the camera 特性。

It is also possible to define where the 3D scene is rendered to using the renderMode property. This can be necessary for performance reasons on certain platforms where it is expensive to render to intermediate offscreen surfaces. There are certain tradeoffs to rendering directly to the window though, so this is not the default.

特性文档编制

camera : QtQuick3D::Camera

This property specifies which camera is used to render the scene. It is possible for this value to be undefined, in which case the first enabled camera in the scene will be used instead.

If it is desired to not render anything in the scene, then make sure all cameras are disabled.

另请参阅 PerspectiveCamera , OrthographicCamera , FrustumCamera ,和 CustomCamera .


environment : QtQuick3D::SceneEnvironment

This property specifies the SceneEnvironment used to render the scene.

另请参阅 SceneEnvironment .


importScene : QtQuick3D::Node

This property defines the reference node of the scene to render to the viewport. The node does not have to be a child of the View3D . This referenced node becomes sibling with possible child nodes of View3D .

注意: This property can only be set once, not removed or changed later.

另请参阅 Node .


renderMode : enumeration

This property determines how the scene is rendered to the viewport.

常量 描述
View3D.Offscreen Scene is rendered to a texture. Comes with no limitations.
View3D.Underlay Scene is rendered directly to the window before Qt Quick is rendered.
View3D.Overlay Scene is rendered directly to the window after Qt Quick is rendered.
View3D.Inline Scene is rendered to the current render target using QSGRenderNode .

默认模式为 View3D.Offscreen as this is the offers the best compatibility.


renderStats : QtQuick3D::RenderStats

Accessor to RenderStats , which can be used to gain information of fps , frameTime , renderTime , syncTime ,和 maxFrameTime .


scene : QtQuick3D::Node

Holds the root scene of the View3D .

另请参阅 importScene .


方法文档编制

vector3d mapFrom3DScene ( vector3d scenePos )

变换 scenePos from scene space (3D) into view space (2D). The returned x- and y-values will be be in view coordinates. The returned z-value will contain the distance from the near side of the frustum (clipNear) to scenePos in scene coordinates. If the distance is negative, the point is behind the camera. If scenePos cannot be mapped to a position in the scene, a position of [0, 0, 0] is returned. This function requires that a camera is assigned to the view.

另请参阅 mapTo3DScene() and Camera.mapToViewport() .


vector3d mapTo3DScene ( vector3d viewPos )

变换 viewPos from view space (2D) into scene space (3D). The x- and y-values of viewPos should be in view coordinates. The z-value should be the distance from the near side of the frustum (clipNear) into the scene in scene coordinates. If viewPos cannot be mapped to a position in the scene, a position of [0, 0, 0] is returned.

另请参阅 mapFrom3DScene() and Camera.mapFromViewport() .


PickResult pick ( float x , float y )

Transforms the screen space coordinates x and y to a ray cast towards that position in scene space. Returns information about the ray hit.