- Qt 6.9
- Qt 3D
- Qt 3D Render C++ Classes
- Qt 6.9.2 Reference Documentation

# Qt 3D Render C++ Classes

The Qt 3D Render module contains functionality to support 2D and 3D rendering using Qt 3D. More...

This module is deprecated since 6.8. We strongly advise against using it in new code.

## Namespaces

Qt3DRender | Contains classes that enable 2D and 3D rendering
Qt3DRender::Render | Namespace used for accessing the classes Renderer and QRenderPlugin

## Classes

Qt3DRender::QAbstractLight | Encapsulate a QAbstractLight object in a Qt 3D scene
Qt3DRender::QAbstractRayCaster | An abstract base class for ray casting in 3d scenes
Qt3DRender::QAbstractTexture | A base class to be used to provide textures
Qt3DRender::QAbstractTextureImage | Encapsulates the necessary information to create an OpenGL texture image
Qt3DRender::QAlphaCoverage | Enable alpha-to-coverage multisampling mode
Qt3DRender::QAlphaTest | Specify alpha reference test
Qt3DRender::QBlendEquation | Specifies the equation used for both the RGB blend equation and the Alpha blend equation
Qt3DRender::QBlendEquationArguments | Encapsulates blending information: specifies how the incoming values (what's going to be drawn) are going to affect the existing values (what is already drawn)
Qt3DRender::QBlitFramebuffer | FrameGraph node to transfer a rectangle of pixel values from one region of a render target to another
Qt3DRender::QBufferCapture | Exchanges buffer data between GPU and CPU
Qt3DRender::QCamera | Defines a view point through which the scene will be rendered
Qt3DRender::QCameraLens | Qt3DRender::QCameraLens specifies the projection matrix that will be used to define a Camera for a 3D scene
Qt3DRender::QCameraSelector | Class to allow for selection of camera to be used
Qt3DRender::QClearBuffers | Class to clear buffers
Qt3DRender::QClipPlane | Enables an additional OpenGL clipping plane that can be in shaders using gl_ClipDistance
Qt3DRender::QColorMask | Allows specifying which color components should be written to the currently bound frame buffer
Qt3DRender::QComputeCommand | QComponent to issue work for the compute shader on GPU
Qt3DRender::QCullFace | Specifies whether front or back face culling is enabled
Qt3DRender::QDebugOverlay | Enables a visual overlay with scene details
Qt3DRender::QDepthRange | Enables remapping depth values written into the depth buffer
Qt3DRender::QDepthTest | Tests the fragment shader's depth value against the depth of a sample being written to
Qt3DRender::QDirectionalLight | Encapsulate a Directional Light object in a Qt 3D scene
Qt3DRender::QDispatchCompute | FrameGraph node to issue work for the compute shader on GPU
Qt3DRender::QDithering | Enable dithering
Qt3DRender::QEffect | Base class for effects in a Qt 3D scene
Qt3DRender::QEnvironmentLight | Encapsulate an environment light object in a Qt 3D scene
Qt3DRender::QFilterKey | Storage for filter keys and their values
Qt3DRender::QFrameGraphNode | Base class of all FrameGraph configuration nodes
Qt3DRender::QFrontFace | Defines front and back facing polygons
Qt3DRender::QFrustumCulling | Enable frustum culling for the FrameGraph
Qt3DRender::QGeometryRenderer | Encapsulates geometry rendering
Qt3DRender::QGraphicsApiFilter | Identifies the API required for the attached QTechnique
Qt3DRender::QLayer | Way of filtering which entities will be rendered
Qt3DRender::QLayerFilter | Controls layers drawn in a frame graph branch
Qt3DRender::QLevelOfDetail | Way of controlling the complexity of rendered entities based on their size on the screen
Qt3DRender::QLevelOfDetailBoundingSphere | Simple spherical volume, defined by its center and radius
Qt3DRender::QLevelOfDetailSwitch | Provides a way of enabling child entities based on distance or screen size
Qt3DRender::QLineWidth | Specifies the width of rasterized lines
Qt3DRender::QMaterial | Provides an abstract class that should be the base of all material component classes in a scene
Qt3DRender::QMemoryBarrier | Class to emplace a memory barrier
Qt3DRender::QMesh | A custom mesh loader
Qt3DRender::QMultiSampleAntiAliasing | Enable multisample antialiasing
Qt3DRender::QNoDepthMask | Disable depth write
Qt3DRender::QNoDraw | When a Qt3DRender::QNoDraw node is present in a FrameGraph branch, this prevents the renderer from rendering any primitive
Qt3DRender::QNoPicking | When a Qt3DRender::QNoPicking node is present in a FrameGraph branch, this prevents the render aspect from performing picking selection for the given branch
Qt3DRender::QObjectPicker | Instantiates a component that can be used to interact with a QEntity by a process known as picking
Qt3DRender::QPaintedTextureImage | A QAbstractTextureImage that can be written through a QPainter
Qt3DRender::QParameter | Provides storage for a name and value pair. This maps to a shader uniform
Qt3DRender::QPickEvent | Holds information when an object is picked
Qt3DRender::QPickLineEvent | Holds information when a segment of a line is picked
Qt3DRender::QPickPointEvent | Holds information when a segment of a point cloud is picked
Qt3DRender::QPickTriangleEvent | Holds information when a triangle is picked
Qt3DRender::QPickingProxy | Can be used to provide an alternate QGeometryView used only for picking
Qt3DRender::QPickingSettings | Specifies how entity picking is handled
Qt3DRender::QPointLight | Encapsulate a Point Light object in a Qt 3D scene
Qt3DRender::QPointSize | Specifies the size of rasterized points. May either be set statically or by shader programs
Qt3DRender::QPolygonOffset | Sets the scale and steps to calculate depth values for polygon offsets
Qt3DRender::QProximityFilter | Select entities which are within a distance threshold of a target entity
Qt3DRender::QRasterMode | Render state allows to control the type of rasterization to be performed
Qt3DRender::QRayCaster | Qt3DRender::QRayCaster is used to perform ray casting tests in 3d world coordinates
Qt3DRender::QRayCasterHit | Details of a hit when casting a ray through a model
Qt3DRender::QRenderAspect | Class
Qt3DRender::QRenderCapabilities | Holds settings related to available rendering engines
Qt3DRender::QRenderCapture | Frame graph node for render capture
Qt3DRender::QRenderCaptureReply | Receives the result of render capture request
Qt3DRender::QRenderPass | Encapsulates a Render Pass
Qt3DRender::QRenderPassFilter | Provides storage for vectors of Filter Keys and Parameters
Qt3DRender::QRenderSettings | Holds settings related to rendering process and host the active FrameGraph
Qt3DRender::QRenderState | An abstract base class for all render states
Qt3DRender::QRenderStateSet | FrameGraph node offers a way of specifying a set of QRenderState objects to be applied during the execution of a framegraph branch
Qt3DRender::QRenderSurfaceSelector | Provides a way of specifying the render surface
Qt3DRender::QRenderTarget | Encapsulates a target (usually a frame buffer object) which the renderer can render into
Qt3DRender::QRenderTargetOutput | Allows the specification of an attachment of a render target (whether it is a color texture, a depth texture, etc... )
Qt3DRender::QRenderTargetSelector | Provides a way of specifying a render target
Qt3DRender::QSceneLoader | Provides the facility to load an existing Scene
Qt3DRender::QScissorTest | Discards fragments that fall outside of a certain rectangular portion of the screen
Qt3DRender::QScreenRayCaster | Performe ray casting test based on screen coordinates
Qt3DRender::QSeamlessCubemap | Enables seamless cubemap texture filtering
Qt3DRender::QSetFence | FrameGraphNode used to insert a fence in the graphics command stream
Qt3DRender::QShaderData | Provides a way of specifying values of a Uniform Block or a shader structure
Qt3DRender::QShaderImage | Provides Image access to shader programs
Qt3DRender::QShaderProgram | Encapsulates a Shader Program
Qt3DRender::QShaderProgramBuilder | Generates a Shader Program content from loaded graphs
Qt3DRender::QSharedGLTexture | Allows to use a textureId from a separate OpenGL context in a Qt 3D scene
Qt3DRender::QSortPolicy | Provides storage for the sort types to be used
Qt3DRender::QSpotLight | Encapsulate a Spot Light object in a Qt 3D scene
Qt3DRender::QStencilMask | Controls the front and back writing of individual bits in the stencil planes
Qt3DRender::QStencilOperation | Specifies stencil operation
Qt3DRender::QStencilOperationArguments | Sets the actions to be taken when stencil and depth tests fail
Qt3DRender::QStencilTest | Specifies arguments for the stecil test
Qt3DRender::QStencilTestArguments | Specifies arguments for stencil test
Qt3DRender::QSubtreeEnabler | Enables or disables entire subtrees of framegraph nodes
Qt3DRender::QTechnique | Encapsulates a Technique
Qt3DRender::QTechniqueFilter | A QFrameGraphNode used to select QTechniques to use
Qt3DRender::QTexture1D | A QAbstractTexture with a Target1D target format
Qt3DRender::QTexture1DArray | A QAbstractTexture with a Target1DArray target format
Qt3DRender::QTexture2D | A QAbstractTexture with a Target2D target format
Qt3DRender::QTexture2DArray | A QAbstractTexture with a Target2DArray target format
Qt3DRender::QTexture2DMultisample | A QAbstractTexture with a Target2DMultisample target format
Qt3DRender::QTexture2DMultisampleArray | A QAbstractTexture with a Target2DMultisampleArray target format
Qt3DRender::QTexture3D | A QAbstractTexture with a Target3D target format
Qt3DRender::QTextureBuffer | A QAbstractTexture with a TargetBuffer target format
Qt3DRender::QTextureCubeMap | A QAbstractTexture with a TargetCubeMap target format
Qt3DRender::QTextureCubeMapArray | A QAbstractTexture with a TargetCubeMapArray target format
Qt3DRender::QTextureData | Stores texture information such as the target, height, width, depth, layers, wrap, and if mipmaps are enabled
Qt3DRender::QTextureDataUpdate | Holds content and information required to perform partial updates of a texture content
Qt3DRender::QTextureGenerator | Provides the image data for a texture
Qt3DRender::QTextureImage | Encapsulates the necessary information to create an OpenGL texture image from an image source
Qt3DRender::QTextureImageData | Stores data representing a texture
Qt3DRender::QTextureImageDataGenerator | Provides texture image data for QAbstractTextureImage
Qt3DRender::QTextureLoader | Handles the texture loading and setting the texture's properties
Qt3DRender::QTextureRectangle | A QAbstractTexture with a TargetRectangle target format
Qt3DRender::QTextureWrapMode | Defines the wrap mode a Qt3DRender::QAbstractTexture should apply to a texture
Qt3DRender::QViewport | A viewport on the Qt3D Scene
Qt3DRender::QWaitFence | FrameGraphNode used to wait for a fence in the graphics command stream to become signaled

## Detailed Description

The Qt 3D Render module provides an aspect, components, and other supporting types necessary to implement 2D and 3D rendering as part of the Qt 3D framework.

To use classes from this module, add this directive into the C++ files:

     #include <Qt3DRender>

To link against the corresponding C++ library, add the following to your qmake project file:

     QT += 3drender

Classes, types, and functions are declared under the Qt3DRender namespace.

### Overview

The Qt 3D Render aspect offers support for data-driven configuration as described in Qt 3D Render Framegraph.

### Selecting a Rendering Backend

The Render aspect comes with two rendering backends.

- OpenGL backend (ES 2, ES 3.2, GL 2, GL 3, GL 3.2, GL 4.3)
- RHI backend (ES 2, GL, DirectX, Vulkan, Metal)

If you are targeting OpenGL exclusively and are using specific OpenGL features, you might be better off using the OpenGL backend. This is the OpenGL backend that Qt 3D exclusively used in the Qt 5 series.

For cases where you are not using specific OpenGL features and want to target different platforms that might have deprecated OpenGL, using the RHI backend is a better alternative.

To select your rendering backend, the environment variable QT3D_RENDERER is to be set to either "opengl" or "rhi". Defaults to the OpenGL backend.

When using the RHI backend, you can further force the internal RHI backend by setting the QSG_RHI_BACKEND to one of the following values:

- opengl -> RHI OpenGL backend
- gl -> RHI OpenGL backend
- gles2 -> RHI OpenGL backend
- metal -> RHI Metal backend
- vulkan -> RHI Vulkan backend
- d3d11 -> RHI DirectX 11 backend

If not specified, RHI will default to what it deduces to be the best backend for the platform.

### Reference

- Qt 3D Render C++ Classes
- Qt 3D Examples