I've just finished reading through this topic and I'd like to thank TReischl for starting this thread and everyone for all the great input.
I've been messing around trying to learn how to do some 2.5d carving and this helps a lot. I am trying to learn Blender and have been going through all the tutorials, it's a very powerful app, but maybe over kill for 2.5d stuff.
Today I was messing around with a gray scale object and found a app on my computer called 3D Builder by Microsoft. I'm guessing it was installed when I upgraded my computer to Win10. I googled it and found it's a free app from Microsoft you can download it at https://www.microsoft.com/en-us/store/a ... zdncrfj3t6
. It two will allow you to extrude gray scale images. I'm playing around with one of TReischi's gray scale images since his are much better quality to see what 3D Builder will do. So far I'm impressed with what it will do and how easy it is to use. There a YouTube videos of course, some better than others.
If you don't have PVC (like me) and want something free to try your hand at creating your own 2.5d objects, check out 3D Builder.