In order to successfully perform a normal bake as intended, there seems to be a trick to the UV development method and smoothing settings.
What does the “angle” in the automatic smoothing setting mean?
Each software has a setting item for automatically applying smoothness. Smoothing is applied to angles that are less than the specified value. So, if you want to avoid applying smoothness to a 90° corner, you will need to set a value smaller than 90°, such as “89°”, or if you want it to be more precise, you should set it to “89.9°”.
There are two main points necessary for normal baking.
① Separate UVs with hard edges in UV expansion
On the low-poly side, decide “edges you want to have sharp edges” (hard edges) and “edges you want smoothed” (soft edges).
② Avoid smoothing hard edges when baking
Set the value of “Setting items for automatic smoothing” of each software to “89.5°” etc. so that smoothing will not be applied to edges where the angle is 90° or more.
3DCoat can highlight hard edges during UV development
3DCoat has a function that helps you add seams to hard edges during UV development. *In 3DCOAT, “hard edge” is treated as “sharp edge” .
Settings required when importing a model for UV unfolding
In order to highlight hard edges in the “UV” room, you need to pay attention to the following settings when importing the model:
Set sharp edges (normal division) on UV seams: If checked, all “edges with seams” will be set to “also be highlighted as sharp edges” and imported. (This is added when importing a model that has already been UV-developed or to the UV-developed results using “auto mapping “, but I can’t think of a use for it at the moment.)
Auto smoothing group/max angle: The edges highlighted by “Show sharp edges” introduced below are set based on this value. A good value would be “89.5”.
Show Sharp edges: When checked, parts corresponding to sharp edges will be highlighted in red in the viewport.
SharpSeams: When you use this tool, edges with angles greater than the value specified in “Fold Angle” will be judged as sharp edges, and if you press “OK”, a seam will be added automatically.