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 for subdividing a WEM in order to produce more nodes, edges and face without modifying the overall geometry.

Details¶

Note: This module works on triangles only!

The WEMSubdivide module searches exhaustively in a WEM for edges with a length that exceeds an adjustable length threshold. Such an edge is split by inserting a node into the middle of the concerning edge (and additionally two edges and two faces are inserted into the WEM). Internally, a priority queue is used and because of that, the longest edges are split first. Additionally, after each run of splitting edges, the module tries to optimize the triangles by applying a edge-swap operation. Also, 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¶

../../../Modules/ML/MLWEMModules/mhelp/Images/Screenshots/WEMSubdivide._default.png

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.

Update Mode¶

name: updateMode, type: Enum, default: AutoUpdate, deprecated name: autoUpdate¶: Defines how this module should react on any input field change.

Apply¶

name: apply, type: Trigger¶: If pressed, the splitting algorithm is applied to the WEM.

Clear¶

name: clear, type: Trigger¶: If pressed, the output WEM is cleared (made empty).

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.

Label¶

name: label, type: String¶: Sets a label string in the output WEM.

Description¶

name: description, type: String¶: Sets a description string in the output WEM.

Subdivision Mode¶

name: subdivisionMode, type: Enum, default: Adaptive Subdivision¶: Selects 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 into half until the resulting new edges are not longer than `Max. Edge Length`. Hence, each edge results in 2^n edges, with n being determined adaptively per 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 into the middle of such an edge.

Local Subdivision¶

name: localSubdivision, type: Bool, default: FALSE¶: If enabled, the PVL Name PVL is used to determine if an edge should be subdivided.

PVL Name¶

name: localSubdivisionPVL, type: String, default: LUT¶: The name of the PVL to use (node and edge PVLs are supported).

PVL Threshold¶

name: localSubdivisionPVLThreshold, type: Double, default: 1¶: The threshold for the PVL value. If the PVL value is >= the threshold, the edge can be subdivided.