|02 February 2018|
[Normal Map] ~ Polys around creased edges don't get baked into the normal map
I've just recently started to follow a game design course which is supposed to guide me through the whole process of creating a video game, from concepting to an Unreal Engine working product.
At the moment we're just one step beyond Maya 3D modeling, which involved making low-poly models of both our own concept and the one supplied by the teacher; the latter being a treasure chest with a skull embedded into the lid.
Now, the next step would be sculpting some details onto the low-poly models and bake them into a normal map (one single map for the whole trunk, skull included), but we've only just started to explore ZBrush.
But I couldnt really wait another week without doing anything (low-poly+UVs ready!), so I've started my own ZBrush sessions with that few information the teacher provided. Enough for me to get past its quirky import/drag-to-draw/edit workflow and start sculpting some details onto the low poly skull.
Now to the problem: the teacher told me to use the "Crease" to maintain certain edges of my skull so that the subdivision process wouldnt eat them away. And so I did, and it made my hi-poly model look much better.
Now, at the third attempt to nail a complete and flawless workflow from low-polys to normal maps I thought I could call it a victory. Three fourths into sculpting my (third) skull I decided to check what the resulting normal map would look like on a hypershade material in Maya, so I baked it and.....why, gods, why?!
The resulting normal map is missing some areas, like they're totally flat. I spent HOURS trying to figure out why. Double checked UVs, triple checked topology, and eventually tried every kind of fix I stumbled on while googling for a solution.
Until a post in a forum thread gave me a hint and so I noticed that the missing areas correspond to the polys surrounding the creased edges. All the teeth and a strip on the temple right behind the eye socket are left unrendered in the normal map and "flat" areas are in their place.
I tried "UnCreasing" the edges, but nothing changed. Top I could manage to achieve was losing the UV mapping (again!!).
I've also tried to bake the normal map with XNormal, but the results vary from an unusable set of weirdly colored squares to an improbable (for a normal map) palette of colors. I mean, for all I know yellow and orange arent supposed to be part of the spectrum, right?
Anyway, now I'm stuck with a nicely sculpted skull that I dont feel like finalizing because I dont know whether I'll have to redo it from scratch thanks to this issue. And I'm not even sure whether to move on to another object, since most of them also need some creased edges to prevent unwanted smoothing.
I'd really appreciate some help to solve this problem. I dont care if I have to start all over again, but I'd like to get to the end of a complete workflow without encountering such crippling issues.
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