Normal Map Problem

Noanoww · Oct 6 2025

Hi guys, newbie here.

So I want to create a 3D asset. I want to bake my highpoly mesh to lowpoly. After baking, I tried the baked result to lowpoly, but why does the result have edges like this in the lowpoly mesh?

Image: https://us.v-cdn.net/5021068/uploads/editor/kd/bz8ew3nt8f2z.png

(Highpoly mesh)

Image: https://us.v-cdn.net/5021068/uploads/editor/nd/lojda40rrrjb.png

(Lowpoly Mesh)

Image: https://us.v-cdn.net/5021068/uploads/editor/uy/trhmc5bomvnl.png

Result

okidoki · Oct 6 2025

Not enough space (in blender, as this seems to be, called margin) between UV-islands ?? Just a guess.. you might give some more info..
Also the low-poly seems to have orthogonal but not-connected faces.. and n-gons.. (even if that part seems to lokk okay).

Neox · Oct 6 2025

looks to me like you do not have UV splits where you have hard edges.

Noanoww · Oct 7 2025

okidoki said:

Not enough space (in blender, as this seems to be, called margin) between UV-islands ?? Just a guess.. you might give some more info..
Also the low-poly seems to have orthogonal but not-connected faces.. and n-gons.. (even if that part seems to lokk okay).

I set my UV padding to 16px and I tried to increase the padding to 32px to bake in 4k resolution textures

Noanoww · Oct 7 2025

Neox said:

looks to me like you do not have UV splits where you have hard edges.

okay, so every hard edge has to have seams?

gnoop · Oct 7 2025

Noanoww said:

okay, so every hard edge has to have seams?

Basically yes , because its already a seam for a videocard and every hard edge is a split edge doubling vertexes along it. Yet not every UV seam needs to be a hard edge and you don't have to always do hard edges along beveled edges. Google and try to understand face weighted vertex/split normals or ask chat GPT?

Shading of any polygonal surfaces is defined by vertex or split (in Blender terminology) normals ( pink vectors) first. Normal map is just a cherry on top of it. Once you figure out the concept of vertex normals and how they create shading the else become instantly obvious.

Neox · Oct 7 2025

https://polycount.com/discussion/107196/making-sense-of-hard-edges-uvs-normal-maps-and-vertex-counts/p1

pior · Oct 7 2025

@Noanoww
"okay, so every hard edge has to have seams?"

To understand it fully, simply observe the current normalmap of this area (and also post a screenshot of it here, for the sake of future people potentially viewing this thread) :

The cause of these artefacts will be pretty much self-evident once you look at it closely.

Noanoww · Oct 7 2025

pior said:

@Noanoww
"okay, so every hard edge has to have seams?"

To understand it fully, simply observe the current normalmap of this area (and also post a screenshot of it here, for the sake of future people potentially viewing this thread) :

The cause of these artefacts will be pretty much self-evident once you look at it closely.

This is the UVs

Image: https://us.v-cdn.net/5021068/uploads/editor/5u/0czopy9eqcju.png

Neox · Oct 7 2025

these are the UV seams maybe, doesnt say much about the actual UVs. but yeah one can certainly see, you dont have seams where the hard edges are

the general rule of thumb is, every hard edge is a UV seam, but not every UV seam is a hard edge.

pior · Oct 7 2025

@Noanoww

Hi,
I am suggesting you to post a *screenshot of the normalmap* corresponding to this area. Once you do so and take the time to observe it closely, you'll understand your issue.

Also, @gnoop , I hate to be a bit of an ass but "Google and try to understand face weighted vertex/split normals or ask chat GPT?" or "something something videocard" isn't contributing anything to help the OP understand the issue. If anything this is just adding even more misinformation/slop to a topic that has been hard to grasp for artists for years.

Celosia · Oct 7 2025

Noanoww said:
This is the UVs

Select the object then look for the "UV Editing" workspace tab at the top. Press "A" to select all geometry. We want to see the UVs that'll appear on the left.

In case there's no image under the UV you can select it from the header in the UV Editor or click on it from a Shader Editor and it'll appear automatically, but in this case having the normal map itself visible isn't necessary to see how the object was unwrapped; you'll see it highlighted as geometry on the left if you selected the vertices (or use UV Sync Selection).

gnoop · Oct 7 2025

isn't contributing anything to help the OP understand the issue.

Yeah, Google maybe is not very specific and helpful advice but chat GPT sure is. I didn't ask it to explain me vertex based shading personally but did for a lot of real time shader and pixel manipulating techniques and it have been best teacher and best focused and compacted info no nvidua published GPU gems ever been for me .

poopipe · Oct 8 2025

the robot is only going to recycle the misinformation
this is a subject that cannot be googled because at least half the people who write with 'authority' on the subject are wrong.

The one good source of information I've found - and the only one I hand over to artists who encounter this - is the sticky thread about wavy normal maps on this very forum.

HAWK12HT · Oct 9 2025

This will help you understand the issue and fix it.

https://www.artstation.com/artwork/rlGqrE

pior · Oct 9 2025

Well, while breakdowns and explanations about wavy bakes are indeed useful, the artefacts in the work of the OP aren't caused by that. They are more than likely caused by the baked pixels of the normalmap instantly jumping from one value to another across the (hard) edge but without UV room to breathe since the UVs have been left continuous instead of being split off. Hence the texture filtering causing improper values to show up on both sides. Or perhaps I am misunderstanding it ; either way, showing the map and the UVs overlaid on top as suggested by Celosia would help.

If anything this one case of hard edge artefacts is great for educational purposes as it is quite clear and self-contained. Looking forward to the OP solving it and this thread perhaps becoming a useful learning resource.

Normal Map Problem

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