Displacement map how do I get it to update as I paint?

So I have been searching around and asking people for weeks. No one knows apparently. Someone asked what kind of displacement? Huh? Displacement map for a plane, I don’t know what other answer you’d be looking for.

How do I get it to show my displacement result as I am painting on the texture? Is it somehow not possible? Do I really have to refresh the image and viewport after each adjustment? I have seen a video where the displacement map is updated as the guy moves his hand in his web cam, so I thought it would be possible.

I don’t really want to sculpt on a subdivided mesh and then bake the displacement. But seems like the closest match so far.

Thread can be closed. Due to the way things work, it cannot update the way I have mentioned. Sculpting then baking will have to do.

Yeah, displacement means real displacement of a subd surface.
However, if baking is what you have in mind, under GLSL + texture painting, you can directly paint B&W image-map and see results in real time. Faked but effective in many cases.

Faked as in bumpmap style?

Bump map painting.
Then, you may even like to convert it to tangent maps (normal), in blender render.
I know nothing about MudBox. I very well know what zbrush does, and it does sculpt on heavy subd meshes, bakes displ maps after.
3dcoat does some more in visualization. It indeed recreates somehow real displacements, in real time. However, it is for visualization only. Performance won’t be great, in this mode.
Fair enough.
It basically depends on your needs.

Yeah don’t think bumpmap style will be good enough, as I want to use a displacement map that can differ quite a lot. Think baking would give a decent displacement map?