Hi Mat,
Sorry for the late reply.
I was trying to have an utility or a script in Paraview that would integrate the requested 3D scalar field f(\vec{x}) along a line of sight \hat{n} , given by the axis parameter (e.g. \hat{i},\hat{j} or \hat{k}) and a weight factor scalar field w(\vec{x}).
g(\vec{X})=\frac{\int f(\vec{x}) w(\vec{x}) \hat{n} \cdot d \vec{x}}{\int w(\vec{x}) \hat{n} \cdot d \vec{x}}
Thus create a 2D projection from 3D scalar field dataset.
These examples are taken from the yt python module which creates such projections
Projection along z-axis:
Projection along an arbitrary axis :
