The inverse for "Normal Map" node

I am aware of this topic Reverse conversion of the “Normal map” node (Cycles) - Support / Materials and Textures - Blender Artists Community, but there is no direct answer there.

I think that showing something like the baked normal map is cool during a VFX, however directing the normals into a base color does not look as a baked normal map, the coordinate space is different. The normals are generated mainly by a bump node with some extra modifications, and I want to be able to preview easily while I am painting the bump.

Hi,

So you want just to invert Normal Map node and that’s it?

I’ve found something here, maybe you should check it out:
https://blender.stackexchange.com/questions/13648/is-it-possible-to-invert-normal-maps-in-cycles

No. I want to get a normal map image, tangent space, from a normal vector purple node from the bump map, without baking.

Something like this one?

Yeah that matcap itself is somehow similar to the VFX I want to achieve, but that one does not count in bumps; going through geometry displacement as the video you attached may be a solution but I think there should be a way much simpler without generating the actual geometry from bump in very high resolution. Since we can convert tangent space normal map to normals via a normal vector without any performance impact, why can’t we do the reverse with a shader node (or group if there isn’t one already, but I actually expected there was one)?

Sorry, I’m not aware of making a normal map without baking, just trying to help to the best of my abilities. However, have you tried to use Multiresolution Modifier for this?

…but you can bake a Normal map from Bump, without needing to generate any geo :thinking: Simply use the bump map with a Bump node in the material, then Bake a normal texture… I think.

I am painting the bump in real time and I want to be able to preview the VFX session in real time when I am painting. Baking now and again is not as convenient.

Check and see if this will help you…start at 0:54
Though he uses a Normal Decal the same would work using standard B/W data from the painted image since you are dealing with Non-color data…

I gave it a shot and made a change to the video settings…since he used a Normal Decal …
Here is what I set up…

and after painting makes a nice Baked Normal Map…