Normal maps and smoothing groups

BenHenry

Alright, after plenty of reading around polycount, I cannot figure this out worth my life. And I figured I better make a thread so it is consistent with my model and such.
So I've sculpted some wooden stairs, here:


So, onto the problem. I've baked down to this lowpoly mesh:


Now, I've got smoothing group splits where the seams are, and matched them up accordingly.
Now, the result in cryengine:


As you can see, the light is directly in front of the model, yet parts are shaded, and obviously we have artifacts here.


So, what I decide to do is make everything hard edge and seperate the Uv's, and this is the result, which fixes that ugly thing but it gives me different errors:

Now, is it because the mesh is too low poly?


I still don't quite understand the smoothing group to normal map relation. And honestly, I've experimented so much, I just want to be sent in the right direction.

So what should I do?

Fwap

Looks like those highlighted faces are all the one smoothing group, un smooth these parts should fix it.

Also looks like one of your channels are flipped in cryengine. I would assume green. this might be causing it.

Jowens

What type of program did you bake in? Did you use a cage? did you xplode youre bake? You may want to look into what kind of format of normal map Cryengine uses (ex. udk uses -Y) it seems you understand the fundamentals of baking and uv'ing for bakes, but you may want to just add more geo to your trouble areas, what could it hurt?

My staircase for the challenge is about 1500 tri's, most of my boards have double and triple bevels, just because i didnt want to fool around with fixing baking errors, and besides thats not that much for 1 asset.

heres a semi close up of my stairs



You're obviously doing the same as I did, you have 2-3 unique steps, and the rest is uv'd separately. (I have 5 unique steps) your problems areas are in the large support beam on the steps. Where you have an angle cube, basically, in theory if you set up your smoothing groups up right, It still should give you a *decent bake.

This is how mine are setup, obviously where i have soft edges there is a quad bevel and where they are hard, is a separate UV island and hard edge (where the seams are, a different smoothing group)




and the normal map, some photooverlay wood detail in there as well



most of my model used smoothed smoothing groups (maya and max is different, im maya) so the double and triple bevels were appropriate to get clean bakes.

You'll want soft edges where uv's are connceted and hard edges where they are not, typically, however if you have enough geo, you can often get away with softening the entire model, it all depends on how high or low you want go go. Also, instead of beveling edges you can add supporting edge loops to your lowpoly ( the same principle as if you were doing a hp sub div model) this will change the way your normals behave, giving you a cleaner bake



both those cubes have the same silhouette, with one smoothing group (all soft) except the one on the right has supporting edges to make it appear more hard...

in the end its all just how you want your model to be really, i recommend checking the wiki as they have more than enough info on the matter.

Also, triangulating your mesh before baking may also help, and will definitely avoid issues.

As you can see, in your model, there is still some weird shading on the bottom edge where you have your geo smoothed, but since the angle at which they are smoothed is so harsh it is still black and weird. You probably need hard edges and UV splits in these areas.

I hope my drunken rambling helps haha...

AlexCatMasterSupreme

I can't tell if you split the UV's on the stairs. It looks like you have hard edges and you should split them. I think you should prolly try moving your islands apart more and then up your padding.

Ace-Angel

Anything that is a hard edge (EI: 90* looking angle kinda deal) then you need to make that it's own Smoothing group and UV split.

If you don't want to do that, then bevel the edge or add support loops.

For more information, please take a gander at the Sticky related to Normals.

AlecMoody

this error:

is the result of the projection splitting at your smoothing splits. If you are baking in xnormal you need to use a custom cage (either imported into xnormal or made inside xnormal) to get the projection to work correctly.

If you are working in maya you can select your cage mesh and average the normals before hitting bake.

Matthew100001

When it comes the islands on the UV map, you want to be as efficient as possible without having any overlap. Padding is important, but you want use as much as you can with the necessary padding to ensure the information meant for one island doesn't leak into another. Either way, I doubt that would be what's causing the smoothing error.