SoPathTracerMesh

InventorModule

author	MeVis Medical Solutions AG
package	MeVisLab/Standard
dll	SoPathTracer
definition	SoPathTracer.def

Purpose

The SoPathTracerMesh module allows for rendering triangle meshes in a SoPathTracer. It supports both opaque and transparent meshes and offers correct integration and blending with the rest of the scene. Transparent meshes are significantly slower to render than opaque meshes, as the rays need to traverse the entire mesh when triangles are transparent.

The inMeshScene can contain any number of SoPathTracerMaterial nodes. A SoPathTracerMaterial affects all meshes that are behind it in the Open Inventor scene. This enables a fast update of material properties without full mesh recreation by setting Mesh Update Mode to UpdateColors.

The meshes are gathered from the inMeshScene and converted into a bounding volume hierarchy (BVH) to facilitate fast ray tracing on the GPU.

Texturing is available via SoPathTracerMaterial; direct support for SoTexture2 is not yet implemented.

Model transformations below the SoPathTracerMesh module are statically applied to the BVH. Model transformations above the SoPathTracerMesh module are applied to the rays directly, eliminating the need to recreate the BVH.

Since the SoPathTracer module itself does not support transformations, you must use SoTransformSeparator or SoResetTransform to ensure that the model transformation at the SoPathTracer is identity.

In this rendering, meshes are utilized for rendering the liver segments and vessels. Note the use of a clipping plane and the ability to enable or disable clipping on individual meshes.

Windows

Default Panel

Input Fields

inMeshScene

name: inMeshScene, type: SoNode

The input scene that is scanned for triangle meshes.

Parameter Fields

Field Index

Enable Clipping: Bool

Enabled: Bool

Flip Clipping: Bool

If checked, the casting of shadows is enabled.: Bool

If checked, the receiving of shadows is enabled.: Bool

Mesh Update Mode: Enum

Update Meshes: Trigger

Visible Fields

Enable Clipping

name: enableClipping, type: Bool, default: TRUE

If checked, Open Inventor clipping planes affect the mesh rendering.

Flip Clipping

name: flipClipping, type: Bool, default: FALSE

If checked, the Open Inventor clipping planes are flipped before being applied to the mesh.

If checked, the casting of shadows is enabled.

name: castShadow, type: Bool, default: TRUE

If checked, the receiving of shadows is enabled.

name: receiveShadow, type: Bool, default: TRUE

Enabled

name: enabled, type: Bool, default: TRUE

If checked, the rendering is enabled.

Mesh Update Mode

name: meshUpdateMode, type: Enum, default: AutoUpdateAll

Defines the update mode.

Values:

Title	Name	Deprecated Name	Description
​Off	​Off		​The meshes are only update when Update Meshes is pressed.
​Auto Update All	​AutoUpdateAll	​AutoUpdateColors	​Automatically updates the scene when only the colors or transparency of materials have changed; otherwise, it is not updated.

Update Meshes

name: updateMeshes, type: Trigger

When pressed, the meshes from the input scene are updated.