3D volume calculation

I have a 3D point cloud and would like to find its volume. My strategy has been to perform a ConvexHull on my tripletwave (x,y,z coords). I have M_Hull and can visualise it in the Gizmo, but I am stuck as to how to get out a volume for it. Any help appreciated. Maybe there is a much simpler way to do this, that I am missing?
Using the convex hull makes sense but you should do so via the operation Triangulate3D. Here is an example:
make/n=(33,3) ddd=enoise(1)  // create sample data
triangulate3d/out=2 ddd  // perform the triangulation and get tetrahedra output

To plot this data use:
Window gizmo0() : GizmoPlot
    PauseUpdate; Silent 1       // building window...
    // Building Gizmo 7 window...
    ModifyGizmo startRecMacro=700
    ModifyGizmo scalingOption=63
    AppendToGizmo Scatter=root:ddd,name=scatter0
    ModifyGizmo ModifyObject=scatter0,objectType=scatter,property={ scatterColorType,0}
    ModifyGizmo ModifyObject=scatter0,objectType=scatter,property={ markerType,0}
    ModifyGizmo ModifyObject=scatter0,objectType=scatter,property={ sizeType,0}
    ModifyGizmo ModifyObject=scatter0,objectType=scatter,property={ rotationType,0}
    ModifyGizmo ModifyObject=scatter0,objectType=scatter,property={ Shape,2}
    ModifyGizmo ModifyObject=scatter0,objectType=scatter,property={ size,0.25}
    ModifyGizmo ModifyObject=scatter0,objectType=scatter,property={ color,1,0,0,1}
    AppendToGizmo Axes=boxAxes,name=axes0
    ModifyGizmo ModifyObject=axes0,objectType=Axes,property={-1,axisScalingMode,1}
    ModifyGizmo ModifyObject=axes0,objectType=Axes,property={-1,axisColor,0,0,0,1}
    ModifyGizmo ModifyObject=axes0,objectType=Axes,property={0,ticks,3}
    ModifyGizmo ModifyObject=axes0,objectType=Axes,property={1,ticks,3}
    ModifyGizmo ModifyObject=axes0,objectType=Axes,property={2,ticks,3}
    ModifyGizmo modifyObject=axes0,objectType=Axes,property={-1,Clipped,0}
    AppendToGizmo Path=root:M_TetraPath,name=path0
    ModifyGizmo ModifyObject=path0,objectType=path,property={ pathColorType,1}
    ModifyGizmo ModifyObject=path0,objectType=path,property={ lineWidthType,0}
    ModifyGizmo ModifyObject=path0,objectType=path,property={ pathColor,0,0,1,1}
    ModifyGizmo setDisplayList=0, object=scatter0
    ModifyGizmo setDisplayList=1, object=axes0
    ModifyGizmo setDisplayList=2, object=path0
    ModifyGizmo autoscaling=1
    ModifyGizmo currentGroupObject=""
    ModifyGizmo showInfo
    ModifyGizmo infoWindow={551,23,1368,320}
    ModifyGizmo zoomFactor=1.180000
    ModifyGizmo endRecMacro
    ModifyGizmo SETQUATERNION={-0.497650,0.659761,0.323963,-0.460555}

If you inspect the wave M_TetraPath you will see that it contains triangle vertices separated by NaN rows. In each triangle the last vertex repeats the first in order to close the path for drawing. If you collect every 4 consecutive triangles you have a full tetrahedron.

Given the list of tetrahedra, you can compute the volume by summing the individual volumes of all the tetrahedra because by definition, the triangulation decomposes the volume into non-overlapping tetrahedra. One way to compute the volume of an arbitrary tetrahedron is using Igor's function MatrixDet(waveT)/6 where waveT is a 2D wave constructed from the vertices of the tetrahedron as follows:

 Make/O/N=(4,4) waveT={{x1,x2,x3,x4},{y1,y2,y3,y4},{z1,z2,z3,z4},{1,1,1,1}}

for a matrix of the form:

I hope this helps,

WaveMetrics, Inc.

Note: in IP7 (after the nightly build) you can get the result directly using the commands:
 Triangulate3D/VOL ddd
Print V_value

Thanks A.G.

The new flag in the nightly build works great.

Edit: deleted my comment about timing since this referred to my own procedure and isn't of interest to anyone else.