Qt3D Renderer Elements

Qt3D Scene Structure and Elements

Renderer elements

The Renderer aspect defines its own set of elements.

Nodes

• Effect

Specifies a list of techniques and default values to be used by the renderer to properly assign shaders and uniforms. =====

• RenderPass

Specifies the ShaderProgram o be used for a pass of a technique. The render pass should have a name.

• Technique

Contains a list of RenderPass elements.

• ShaderProgram

Has paths pointing to fragment and vertex shader sources.

FrameGraphItems

Only a single framegraph can be used at any moment for the rendering of the scene.

• Viewport

Defines the viewport rectangle to be used.Note : The viewport rectangle is defined from top left unlike OpenGL which defines it from bottom left. =====

• CameraSelector

Defines the camera entity to be used.

• RenderPassFilter

Defines the name of the RenderPass to be used.

• RenderTargetSelector

To be done - Defines the RenderTarget (Texture/FBO/Screen)

• TechniqueFilter

Defines the name of the technique to be used.

Entity

• Scene

Has a source property that can be set to the path of a 3D scene file to be loaded into the current scenegraph tree.

Components

• Mesh

Specifies the path toward a mesh source file.

• Material

Specifies an Effect and may override uniforms set by the Effect to be used by the Techniques' ShaderPrograms Also specifies the textures.

• Shape

Can be a shaper of one of the types : ' Cube ' Sphere ' Cylinder ' Torus Additional properties allow to further define the shape and its precision. =====

 Mesh {
 id: ballMesh
 objectName: "ballMesh"
 source: ":/assets/ball.obj"
 }

Material {
 id: ballMaterial
 objectName: "ballMaterial"
 // effect: adsEffect

// Custom properties go here
 }

Entity {
 id: ball
 objectName: "ball"

property Transform transform: Transform {
 Translate{ dx: 0; dy: –10; dz : 25 }
 Scale {scale : 0.1}
 }
 property Mesh mesh: ballMesh
 property Material material: ballMaterial
 }

• FrameGraph

Defines the tree of FrameGraphItems to be used as the rendering pipeline. ====

import Qt3D 2.0
import Qt3D.Render 2.0

TechniqueFilter {

property alias viewportRect: viewport.rect
 property alias cameraViewportTopRight: cameraSelectorTopRight.camera
 property alias cameraViewportBottomLeft: cameraSelectorBottomLeft.camera

tags: [
 Tag { name: "style"; value: "forward"}
 ]

Viewport {
 id: viewport
 objectName : "viewport"
 rect: Qt.rect(0.0, 0.0, 1.0, 1.0) // From Top Left

Viewport {
 id : top_right_viewport
 rect: Qt.rect(0.5, 0, 0.5, 0.5)
 CameraSelector {
 RenderPassFilter { renderPassName: "zFill" }
 RenderPassFilter { renderPassName: "lighting" }
 }
 }

Viewport {
 id : bottom_left_viewport
 rect: Qt.rect(0.0, 0.5, 0.5, 0.5)
 CameraSelector {
 RenderPassFilter { renderPassName: "zFill" }
 RenderPassFilter { renderPassName: "lighting" }
 }
 }
 }
}