title: Transfer Functions in xtk
body: <p>How would I go about plugging in a transfer function to determine coloring and opacity in xtk based on pixel scalar intensity and / or gradient magnitude. This may be a separable 1d transfer Functions or a <a href="https://blog.kitware.com/2d-transfer-function-support-in-gpuvolumemapper/" rel="nofollow noreferrer">2d transfer function</a>. In addition to VTK, <a href="http://www.sci.utah.edu/software/145-news/software-news-cibc/352-iv3d-2-0.html" rel="nofollow noreferrer">ImageVis3D</a> also supports this. </p>