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How can I draw (not bake) normal map over my model, like a texture in texture paint mode? Render cycles.

Thank you in advance!

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    $\begingroup$ I don't think you can draw a normal map directly like that, at least not easily. You could however pain a bump map $\endgroup$ – Duarte Farrajota Ramos Apr 5 '17 at 0:45
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    $\begingroup$ Check this, it's possible: youtu.be/TMbx5UVjz7Q $\endgroup$ – cgslav Apr 5 '17 at 1:43
  • $\begingroup$ @LukeD Thank you! I downloaded the blend file from the creator of this video, but i can't understand how to use it yet... $\endgroup$ – Rumata Apr 5 '17 at 17:14
  • $\begingroup$ @DuarteFarrajotaRamos Yes, but I need to have a normal map at the end. However, I think I will try to turn bump texture into a normal map. $\endgroup$ – Rumata Apr 5 '17 at 17:17
  • $\begingroup$ @Rumata Check my answer, I think you'll manage to get this working. $\endgroup$ – cgslav Apr 5 '17 at 17:50
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It is easier and more intuitive to paint a height-map, then convert it into a normal map:

enter image description here

There is GIMP normalmap plugin, Photoshop plugins like xNormal, apps like CrazyBump and a lot of others. These all can do the conversion. Also, it can be done through Blender Baking.

If you already have a normal map, and you need to add to it, you can combine normal maps with overlay blending operation - generally it is ok enough but note that it is not the correct operation - more on combining normal maps is here: Blending in detail.

You can also paint directly into normal maps:

  • you can erase with RGB[128,128,255] brush
  • you can average with ordinary Soften (smooth) brush
  • you can smudge with Smear brush
  • you can paint with a special texture brush:

    1. create a brush height texture that you want to paint with
    2. convert to normal map texture

      enter image description here

    3. paint with this texture in overlay mode. It will be like sculpting, but on a texture. The brush color must be white, spacing of strokes very low and strength of brush also low

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  • $\begingroup$ Worth noting that the conversion can be done with baking within blender. You can set the height map as bump map in BI and then bake it to a tangent space normal map, no need for external software. $\endgroup$ – Sazerac Apr 6 '17 at 1:12
  • $\begingroup$ @Sazerac Yep, very true. Thanks for adding this. I don't paint textures in Blender so that makes Blender baking external software for me and those plugins actually internal, that's why it didn't hit me as solution right away. $\endgroup$ – Jaroslav Jerryno Novotny Apr 6 '17 at 9:19
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Result:

Final

Credits:

First of all this is not my work, it's from riceart41 on BlendSwap (download this file to make all of this to work). You can find more information on YouTube and on BlenderArtists.

Overview:

There is no accurate tutorial from the creator of this method but I've managed to get it to work in a way presented below:

overview

You'll need to create Paint Slot, assign it to Height Map Image in Texture Group and connect Normals to shaders.

Don't forget to set Texture X and Texture Y size in Bump_to_normal group accordingly to created Paint Slot.

That's really all you'll need to do.

I don't know what sorcery is behind this but it is converting Height Map to Normal Map pretty good.

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  • $\begingroup$ Invaluable information. Thank you very much. $\endgroup$ – Rita Geraghty Feb 27 at 17:15

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