SoGVRGradientVolume

InventorModule
genre VolRendExtensions
author MeVis Medical Solutions AG
package MeVisLab/Standard
dll SoGVR
definition soGVR.def
see also SoGVRVolumeRenderer

Purpose

The SoGVRGradientVolume module allows for setting a gradient volume that the SoGVRVolumeRenderer Illuminated mode will use instead of the internal Sobel3D filter.

Usage

The input image must have the same size as the input volume of the SoGVRVolumeRenderer. The gradient volume has to be unsigned int8 data. The image can either be an RGB, RGBA, or Luminance image. The RGB component is interpreted as the gradient packed as unsigned int8. For a gradient in the range [-1, 1], the integer value is calculated component-wise as given below:

myIntGradientX = uint8(myFloatGradientX * 127) + 128;

The A or L component provides the gradient strength normalized from 0-255. If the image is a Luminance image, the gradient direction is calculated by the Sobel3D filter and the Luminance values are used as gradient strength.

Tips

The internal gradient estimator is quite good, so you seldom need this module, except when you want to experiment with different gradient strength values. It also has the disadvantage that it is a rather large additional volume (1-4 times the original image).

Input Fields

image

name: image, type: Image

ML image to use as gradient volume.

inVolume

name: inVolume, type: GVRVolume(MLBase)

GVRVolume to use as gradient volume.

Output Fields

self

name: self, type: SoNode

A node that should be put in front of the SoGVRVolumeRenderer