VoxelizeWEM

MLModule

author	MeVis Medical Solutions AG
package	MeVisLab/Standard
dll	MLOpenVDB
definition	MLOpenVDB.def
keywords	distance

Purpose

The VoxelizeWEM allows for voxelizing the surface of a WEM mesh to a given reference coordinate system defined by the input image (but only within the bounds of the input image). It supports both voxel thickness and world thickness; however, using voxel thickness is considerably faster. Additionally, it can fill the interior and provide anti-aliasing.

It utilizes the OpenVDB library.

Tips

If you want to voxelize the WEM to an image that has the appropriate size, you might consider using the GenerateImageForBoundingBox module, which will create an image grid of the needed size aligned to the world axes if you provide it with the bounding box values from, for example, WEMInfo module.

Windows

Default Panel

Output Fields

output1

name: output1, type: Image

The index of the closest triangle.

output2

name: output2, type: Image

The index of the closest node.

output3

name: output3, type: Image

The closest PVL value.

output4

name: output4, type: Image

The closest normal.

Parameter Fields

Field Index

Anti-aliasing: Bool	Invert Normals: Bool	PVL name: String
Clear: Trigger	Mode: Enum	Surface: Bool
Distance Mode: Enum	Normal Mode: Enum	Surface Thickness: Float
Exterior Bandwidth: Double	Normal Type: Enum	Update: Trigger
Fill Inside: Bool	Output Closest Node: Bool
Interior Bandwidth: Double	Output Closest Normal: Bool
Interpolate PVL: Bool	Output closest PVL: Bool
Invalid PVL value: Double	Output Closest Triangle: Bool

Visible Fields

Update

name: update, type: Trigger

When pressed, the output according to all parameters is updated.

Clear

name: clear, type: Trigger

When pressed, the output is cleared.

Mode

name: mode, type: Enum, default: Surface

Defines the mode in which the module operates.

Values:

Title	Name	Description
Signed Distance	SignedDistance	The module outputs a signed distance field, using float as the output data type. The distance is positive outside a closed mesh and negative inside.
Surface	Surface	The module outputs the surface and can optionally fill it and apply anti-aliasing.

Distance Mode

name: distanceMode, type: Enum, default: VoxelDistance

Defines whether the distance calculations use world or voxel distances.

The distance mode is utilized for Surface Thickness and for the output distances in SignedDistance mode.

NOTE: World distances are significantly slower, as the grid needs to undergo an extra resampling step.

Values:

Title	Name	Description
World Distance	WorldDistance	Use world distances in millimeters.
Voxel Distance	VoxelDistance	Use voxel distances.

Surface

name: surface, type: Bool, default: TRUE

If checked, the surface is voxelized.

Surface Thickness

name: surfaceThickness, type: Float, default: 1

Sets the thickness of the surface in voxels.

Fill Inside

name: fillInside, type: Bool, default: TRUE

If checked, the inside of closed meshes is filled.

Anti-aliasing

name: antiAliasing, type: Bool, default: TRUE

If checked, anti-aliasing on the borders of the surface and/or the filling is enabled.

Interior Bandwidth

name: interiorBandwidth, type: Double, default: 3, minimum: 1

Sets the inner bandwidth in voxels when SignedDistance mode is used.

The signed distance field is propagated only this far into the interior of a surface. All other inner voxels are set to the bandwidth distance.

Exterior Bandwidth

name: exteriorBandwidth, type: Double, default: 3, minimum: 1

Sets the outer bandwidth in voxels when SignedDistance mode is used.

The signed distance field is only propagated this far outside of a surface. All other outer voxels are set to the bandwidth distance.

Output Closest Triangle

name: outputClosestTriangle, type: Bool, default: FALSE

If checked, output1 outputs an int32 image, where the values indicate the closest triangle index of the WEM.

Output closest PVL

name: outputClosestPVL, type: Bool, default: FALSE

If checked, output3 outputs a double image where the values indicate the closest PVL value specified in PVL name.

Interpolate PVL

name: interpolatePVL, type: Bool, default: FALSE

If checked, per-node PVL values are interpolated using the barycentric coordinates of the triangle. Otherwise, the closest point’s PVL value is used without interpolation.

Invalid PVL value

name: invalidPVLValue, type: Double, default: 0

Sets the value that is written where no PVL value is available.

PVL name

name: pvlName, type: String, default: LUT

Sets the name of the PVL that is used. The module supports per-face and per-node PVLs.

Invert Normals

name: invertNormals, type: Bool, default: FALSE

If checked, the normals of the normal output image are inverted.

Output Closest Node

name: outputClosestNode, type: Bool, default: FALSE

If checked, an image with the indices of the closest WEM node is output at output2.

Output Closest Normal

name: outputClosestNormal, type: Bool, default: FALSE

If checked, the closest normals are output in output4.

Normal Mode

name: normalMode, type: Enum, default: FaceNormal

Defines which normals are used.

Values:

Title	Name	Description
Face Normal	FaceNormal	The closest face’s normal.
Node Normal	NodeNormal	The normal of the closest node.
Interpolated Node Normal	InterpolatedNodeNormal	The interpolated normal of the closest face’s node normals (renormalized).

Normal Type

name: normalType, type: Enum, default: Type_UInt8

Defines the data type of the normal output image.

Values:

Title	Name	Description
UInt8	Type_UInt8	Uint8 in three color channels, in the range of 0-255 (centered around 128). This format can be used for the SoGVRGradientVolume.
Double	Type_Double	Double values ranging from -1 to 1 in three color channels.
Vector3	Type_Vector3	Vector3 is used for the normals.