I’m trying to bake a normal map for this small pot mesh I plan on texturing later, but the resulting normal maps present lots of issues around the edges.
I’ve tried baking from a higher poly model to this lower poly version and with only the lower version, as well as changing the ray distances from 0 to 0.01,0.1,1 and 10, without sucess. I also tried a lot of different edges and bevels along with other ways of UV unwrapping but can’t get it work.
Here are some pictures of the low poly mesh with and without the Subdivision:
The UV for the body.
The higher poly is the same with more subdivisions.
I understand that the indentation near the base can cause issues since it’s very small (the whole pot is scaled realistically, and around 17 cm in diameter), but the remaining edges are also having issues and I don’t understand why.
I can post the Blend file, if more information is required.
In general I know of 2 situations where baking normals goes wrong:
The meshes of both objects intersect with each other. The normals of the high-poly mesh always need to point toward the low-poly.
Projection problems. If the low-poly mesh is strongly curved and/or the distance to the high-poly is too large, projection can get highly distorted or even discontinuous.
It could be either in your case. It might help to tweak the low-poly. Make it smoother. Make sure the high-poly is on the inside of the low-poly everythere, but close to it.
Just to add, you cannot judge a tangent-space normal map by how the normal map appears visually at seams. Color discontinuities at seams are expected and do not necessarily translate into normal discontinuities. The color is a measure of the new normal relative to the old normal and the UV tangent, and the UV tangent can be different for every island. (Even different for a single island, although continuous over the space of that island.)
In this case, the issues, specially around the crevice near the bottom and on the end and beggining of the handle are affecting the posterior bake of the AO and curvature maps which I need to texture the object. I’m not even that interested on the normal map, just need for the other bakes, or to at least fix the same issues that carry on the other kinds of bake. I would be fine baking with the low poly alone if it works.
Here is the blend file if anyone else is interested in taking a look. small pot.blend (1.3 MB)
Okay, thanks. Yes, the meshes are aligned so closely that one cannot tell anymore which is above, and as you already said yourself the bottom is highly creased.
If it is possible, baking onto the same object (not selected to active) is certainly preferred, as you will get rid of the issue completely.
You lost me, though, about the problems with baking AO and curvature. I decided to try AO, which works fine when baking onto the low-poly itself. Temporarily increasing the subdiv level for baking makes the result somewhat smoother, of course. When I did it, I got a weird glitch, though. At first there were holes in the bake near the bottom of the pot. But it wnet away after clicking around a bit, switching modes, selecting other objects and such. Is that what you also ran into, maybe?
The issues were mostly around the hard edges, of the top where the lid goes, the indentantion and the bottom. After a lot of messing around, and some more researching, I think that the main issue was the very hard edges, with a bigger angle than 90º.
I went back to only baking from the low poly, but upped the subdvisions, beveled all the hard edges and changed my UVs from the edges themselves to something closer to them. That seems to fixed most of the issue.
It’s not a perfect solution of course, since now the model isnt’t low poly at all, and the UVs are kinda weird. Which for the purpose of just practicing texturing isn’t a big deal, but in the future I would have to find an workaround the edges.