3d preview for handpainted normal maps?

What are the advantages to having this Feature? How will it benefit MyPaint’s work flow?

Helps bridge the gap between 2d and 3d art. Great for artists who prefer the 2d workflow but want dynamic lighting or working in asset design.

What will be the challenges to adding this feature?

My paint currently does not support a 3d workflow

Do you have any mockups or examples from other programs which implement this?

This is something Spriteilluminator does, but sadly does not have all the tools available in my paint.

Hand Painted normal map for reference

It seems to me like this is something very much outside the scope of MyPaint. Isn’t it easier to just use e.g. Blender together with a texture reloading add-on (GitHub - samytichadou/Auto_Reload_Blender_addon: Handy automatic reload for Image Textures)? That way you can work on your texture in MyPaint and see the results using Blender’s render preview.

Additionally, normal maps are often created for use with specific geometry, so I don’t see a generic flat preview being very useful. Apart from that, isn’t it very unusual to work with normal maps manually, except for minor edits? My experience is that they are almost always generated in one way or another.

I think the issue is misunderstood here. This isn’t a 3d model. This is a 2d drawing, with a painted normal map. I’m not doing anything with textures at this point.

It is a bit niche, but it is it’s own medium and can give you better results than generated normal maps. Typically hand drawn normal maps are done in photoshop because of the 3d preview it has.

I’ll give blender a shot, but I’m not a 3d artist and have never touched the software before.

Ah, I sort of understand the use-case now. I still think this is out-of-scope for MyPaint, but I can see where it might be useful for asset-generation. Out of curiosity, do you have any links to tutorials or examples of this kind of workflow?

To me it seems more clunky and less powerful than “just using blender”, but I tend to forget the amount of time I had to spend with 3d-software back in the day to reach my current proficiency.

Edit: Here’s a post about use cases for game development: Handmade Normal Maps | Simonschreibt. Really cool stuff (but my previous personal opinion still stands).