Hi guys, I am not sure what is the problem for my baking but it seems it is not going well.
One question: Do I have to UV unwrap before duplicating and sculpting the original object?
I’d suggest unwrapping your target mesh after both your objects are done.
It’s hard to tell why your bake is failing just from the screenshot. At a casual glance, things look about correct. I’d suggest combining all your objects together into two objects, one low poly, and one high, and see how that does.
Really, the only thing you have to worry about is that your low poly mesh is unwrapped. It doesn’t matter for the high.
As for your goofy normals, it looks like what you’d get if you have your surfaces crammed too closely together, causing the rays to hit another surface after passing through the intended target, confusing the calculation. The thing is, your object is fairly simple, doesn’t really have any extraneous, overlapping details in any tight corners. There’s gotta be something else going on.
If you’re up to it, go ahead and upload your blend file. Admittedly, I’m still fairly new to baking myself, but I have a few success attempt under my belt by this point, so I might be able to help you out.
…and I also suggest reading this in the meanwhile. It helped me out considerably.
I have finally found the cause of the problem!
Right before I duplicate the simple mesh and start sculpting, I have applied a displacement modifier. And I should have done it to the sculpted equivalent instead.
Thanks again for the reply and I am grateful for the info provided! Feels so good to have a community behind for pushing myself further 