WEMSubdivide

MLModule

genre	WEMProcessing
author	MeVis Medical Solutions AG
package	MeVisLab/Standard
dll	MLWEMModules
definition	MLWEMModules.def
see also	WEMReducePolygons
inherits from	WEMProcessor
keywords	split, surface

Purpose

The module WEMSubdivide can be used to subdivide a WEM in order to produce more nodes, edges, and faces without modifying the overall geometry.

Details

Note: This module works on triangles only!

The WEMSubdivide module searches exhaustively in a WEM for edges with lengths that exceed an adjustable length threshold. Such an edge is split by inserting a node into the middle of the corresponding edge (and additionally, two edges and two faces are inserted into the WEM). Internally, a priority queue is used; because of this, the longest edges are split first. Additionally, after each run of splitting edges, the module attempts to optimize the triangles by applying an edge-swap operation. Furthermore, the faces’ normals are smoothed before checking for a potential swap.

Tips

The average edge length can be determined with the WEMInfo.

Windows

Default Panel

Input Fields

inWEM

name: inWEM, type: WEM(MLBase)

Any valid WEM that contains only triangles.

For accessing this object via scripting see the Scripting Reference: MLWEMWrapper.

Output Fields

outWEM

name: outWEM, type: WEM(MLBase)

The subdivided WEM.

For accessing this object via scripting see the Scripting Reference: MLWEMWrapper.

Parameter Fields

Field Index

Apply: Trigger	listenToFinishNotifications: Bool	PVL Threshold: Double
Auto Apply: Bool	listenToRepaintNotifications: Bool	shouldComputeNormals: Bool
Clear: Trigger	listenToSelectionChangedNotifications: Bool	Subdivision Mode: Enum
Description: String	Local Subdivision: Bool	triangulationMode: Enum
elapsedTime: Float	Max. Edge Length: Float	Update Mode: Enum
id: Integer	Overwrite label and description: Bool	workDirectlyOnInputWEMs: Bool
isProcessing: Bool	progress: Float
Label: String	PVL Name: String

Visible Fields

Auto Apply

name: autoApply, type: Bool, default: TRUE

If checked, all parameter changes take immediately effect.

see also WEMGenerator.autoApply

Update Mode

name: updateMode, type: Enum, default: AutoUpdate, deprecated name: autoUpdate

Defines how this module should react on any input field change.

see also WEMGenerator.updateMode

Apply

name: apply, type: Trigger

When pressed, the subdividing algorithm is applied to the WEM.

see also WEMGenerator.apply

Clear

name: clear, type: Trigger

When pressed, the output WEM is cleared (made empty).

see also WEMGenerator.clear

Overwrite label and description

name: overwriteLabelDescription, type: Bool, default: FALSE

If checked, label and description strings are set in the output WEM to Label and Description.

see also WEMGenerator.overwriteLabelDescription

Label

name: label, type: String

Sets a label string in the output WEM.

see also WEMGenerator.label

Description

name: description, type: String

Sets a description string in the output WEM.

see also WEMGenerator.description

Subdivision Mode

name: subdivisionMode, type: Enum, default: Adaptive Subdivision

Selects a subdivision mode.

Values:

Title	Name	Description
Split Each Edge Once	Split Each Edge Once	Each edge is split into two edges, independent of the edge length.
Adaptive Subdivision	Adaptive Subdivision	Each edge is recursively split in half until the resulting new edges are not longer than Max. Edge Length. Thus, each edge results in 2n edges, with n being determined adaptively for each edge.

Max. Edge Length

name: maxEdgeLength, type: Float, default: 1

Sets the maximum length an edge can have in a WEM. If any edge exceeds this length, it will be split by inserting a node in the middle of that edge.

Local Subdivision

name: localSubdivision, type: Bool, default: FALSE

If enabled, the PVL Name Primitive Value List is used to determine if an edge should be subdivided.

PVL Name

name: localSubdivisionPVL, type: String, default: LUT

Sets the name of the Primitive Value List (PVL) to use (only node and edge PVLs are supported).

PVL Threshold

name: localSubdivisionPVLThreshold, type: Double, default: 1

Sets the threshold for the Primitive Value List (PVL) value. If the PVL value is greater than or equal to the threshold, the edge can be subdivided.

Hidden Fields

isProcessing

name: isProcessing, type: Bool, persistent: no

see WEMGenerator.isProcessing

elapsedTime

name: elapsedTime, type: Float, persistent: no

see WEMGenerator.elapsedTime

id

name: id, type: Integer, default: 0

see WEMGenerator.id

shouldComputeNormals

name: shouldComputeNormals, type: Bool, default: TRUE

see WEMGenerator.shouldComputeNormals

workDirectlyOnInputWEMs

name: workDirectlyOnInputWEMs, type: Bool, default: FALSE

see WEMProcessor.workDirectlyOnInputWEMs

listenToFinishNotifications

name: listenToFinishNotifications, type: Bool, default: TRUE

see WEMProcessor.listenToFinishNotifications

listenToRepaintNotifications

name: listenToRepaintNotifications, type: Bool, default: TRUE

see WEMProcessor.listenToRepaintNotifications

listenToSelectionChangedNotifications

name: listenToSelectionChangedNotifications, type: Bool, default: TRUE

see WEMProcessor.listenToSelectionChangedNotifications

progress

name: progress, type: Float, persistent: no

see WEMProcessor.progress

triangulationMode

name: triangulationMode, type: Enum, default: Strip

see WEMProcessor.triangulationMode