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XVOL-RESAMPLE-VOLUME

source files: xvol.[ch]

SYNTAX

(XVOL-RESAMPLE-VOLUME
  :VOXELS <grl:voxels>
  :RESULT-IN <grl>
  :TRANSFORM <modelling-matrix>
[ :RENDERING-RELATION <grl:rendering-relation> ]
[ :FILTER-SHAPE { :IMPULSE | :BOX | :TRIANGLE | :QUADRADIC | :MITCHELL  } ]
)

DESCRIPTION

This function samples values at a given set of points within a volume dataset. A typical use is to compute and display arbitrary slices through a dataset by constructing a rectangular surface built of (say) a 64x64 array of quadralateral polygons, assigning each vertex in this surface an appropriate color, and then displaying the resulting model.

The :VOXELS argument must (currently) be a 256x256x256 or 128x128x128 16-bit voxel array.

The :TRANSFORM argument must be a 4x4 tranform matrix. This matrix specifies the location of the :RESULT-IN points within the :VOXELS array, which for this purpose is currently understood to occupy a space with the origin at the center and the extremes at (-1.0, 1) on each axis.

The :RENDERING-RELATION, if present, must be as in xvol-build-rendering-relation. (See section XVOL-BUILD-RENDERING-RELATION.) See next.

The :RESULT-IN argument must be a graphic relation containing :POINT-X, :POINT-Y and :POINT-Z float arrays. This relation will normally be a thing :POINT-RELATION. If a :RENDERING-RELATION is present, xvol-resample-volume returns its results in CLASS-UNIT-FLOAT-ARRAY :POINT-RED, :POINT-GREEN :POINT-BLUE arrays in the :RESULT-IN, which will be created if missing or of wrong type. If a :RENDERING-RELATION is not present, xvol-resample-volume returns its results in a CLASS-16-BIT-FLOAT-ARRAY.

The :FILTER-SHAPE parameter is currently ignored.


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