Sorry for joining the conversation so late. I didn’t know this was going on and Andras just told me about it.
@Sunderlandkyl, this is really exciting work! I have wanted something like this for a while. The main reason why it is important is for interactive rendering and in particular volume rendering. For regular image processing tasks, users can often tolerate to wait a second or two. For volume rendering, many advanced illumination techniques rely on the ability to preprocess certain information over the whole volume and at interactive rates. For example, most recent volume self-shadowing techniques need to pre-integrate light attenuation every time the position of the light source or the transfer function change. There are many more application.
VTK-m looks nice, but I think most medical imaging projects such as Slicer are not willing to pay the price of such a heavy dependency to obtain advanced rendering, so it makes a lot of sense to integrate your work in VTK itself. Please let me know if you are still considering integrating this work in VTK. I could help with making sure the GPU volume rendering classes supports it.