Trouble baking a character, Weird seams on her side.

Nizidranamitz

Hello people ! This is my second thread on polycount (first being long, long ago when I presented myself on the appropriate forum). Nice to meet you all !

I have been modeling a Character on Zbrush, did the retopo and all the stuff buuut since this character have overlapping clothes, I had to set up a tedious exploded baking.

Here is the result : Bake is overall quite okay every where, but on the side of my character there are HUGE, tremendous, UGLY seams who wreck its all . Also, Some seams I did for UV are showing off in the normal a lot for some reason, like on the back of her arms.

Last but not least, the AO I baked from the non-exploded mesh is really weird . Maybe the cage...

Help me, please !

AtticusMars

Those don't look like seams, they look like projection errors from your cage not being far enough from your high poly mesh. Try pushing your cage out in those spots and see if it improves

Edit: Also that's a pretty crazy unwrap, unless your character is going to need to remove the armor at some point then you should just delete everything that will be hidden. If the character does need to remove it then I'd break them off into their own texture sheets personally.

Edit 2: Not 100% sure but it also looks like your green channel might be flipped

Nizidranamitz

Hey, Thanks a lot for the reply Atticusmars ! Yes the green channel was flipped, I fixed that ! Alriiight I'll try that for the uv, thanks !


I tried pushing back but it didn't work ...  however I double Checked the normal and the distortion always appears at the same area on unrelated element. Here is the normal. In my opinion, the issues is the (indeed) crazy UV. Its seems that the normals of separates elements are bleeding onto another  .I Guess i'll just have to redo the UV and baking. I'll try to separate UV sheets, I hope it ll solve the issue.

Nizidranamitz

Okay, I v tried to separate the mesh in four UV sheets and rebake it. Sames problems arises , but I can give a more precise diagnosis. Its seems some part of the mesh are like mirrored in the normal... like the reflection of the item is baked into it.  Its weird, I did a cage matching the subtools though.

Here is how I proceeded, tell me if I did a mistake

First try exploded bake : Used Xpose to explode the mesh, GoZ to max, Matched Low poly with subtools, did a cage in max, imported low poly and cage. For the HP, I kept the xpose and merged all subtool at maximum resolution and imported it as the hight poly.

Second try : did 4 separate UV sheets with no clothes overlapping each other. Once again, same issue at same spot (face, top, glove, pants) but the ''reflection'' is clearer.

May you help me please ?




 

AtticusMars

Yep, like I said, those are projection errors. There's something wrong with your cage, could be too close or too far away. You basically need your cage to be as close to your low poly as possible without intersecting it.

Nizidranamitz

I see... Thanks for answering me.  Its my first time ever having this kind of issues with baking, maybe because my older characters were continguous meshes...

I tried pushing the cage very far aways, or getting it as close as possible and its still the same results Here is a quick screen of the cage. Since the low poly has holes in it, it has holes as well, is it an issue?
 Gold color mesh is the low poly and the red one is the cage. As you can see they are very tighly matching. Even when I push the jaw lower or even push the whole mesh way further, I still have the same artifacts.


 

AtticusMars

Ugh sorry I misspoke, it the cage has to be as close to your HIGH poly as possible without going through it, not the low poly. The raycasts from your cage have to hit the high poly, if your cage is going through it then they will cast through the mesh and pick up the first thing it hits meaning you could get a hand on a thigh. The same applies if your cage is pushed too far out, it will pick up objects between the cage and the mesh it's trying to cast to.

It won't always be obvious in your 3D program that the cage is too close, it might look fine. This is when you do a test bake so you can see where the errors are.

The way I tend to make cages is I duplicate hte low poly, give it a push modifier, then do a test bake. If there are projection errors then I push the cage out a bit more in those spots by manually tweaking it and do more test bakes, and I just repeat until the bake is clean.

musashidan

It's as if you r cage is encompassing the entire model rather than each individual element, so all the outer parts are projecting down to the character in the middle. 

Macebo

Also, since you exploded the model, make sure that the high poly meshes are occupying the same space as the respective low poly ones.

EarthQuake

Macebo said:

Also, since you exploded the model, make sure that the high poly meshes are occupying the same space as the respective low poly ones.

Yeah, it looks like it's missing the high entirely and casting onto different sections of the high. This will happen if your high and low aren't properly aligned.

Scruples

Edit: Which software are you baking in, Max? If it's in Xnormal make sure the scale is set correctly in both 'High' and 'Low' tabs. I wouldn't use GoZ either, might be doing something strange to the transforms. Export with Subtool master.

Nizidranamitz

I see .  I understand better what's happening, thanks everyone for your feedback !

@Atticusmars Thanks for the thorough explanation. I checked with the HP from GoZ but its seems there is some issue with the HP position in Zbrush.
@Musashidan:  Okay, I get it .
@Macebo : I'll doublecheck it.
@EarthQuake I'll triple check it .
@Scruples : I'm baking in Xnormal, the mesh scale and default mesh scale is set to 16 in both Hight poly and Low poly tabs . Max frontal ray distance is 0.5 and I use exported normal.  As for the GoZ, its, it might be what's disfunctionning.  Maybe the hight poly is actually way smaller than the max version and that's the issue.

I'll try and export with Subtool master, and see if I didn't screw the mesh scale during export .

EarthQuake

The easiest way to check is to pop into the 3d viewer in xnormals, there you can set up a cage too.

Nizidranamitz

Thanks Eartquake its helped

So... I fixed it ! Thanks so much for your feedback guys, I wouldn't have made it without you !!!
The issue was, like you all told me, a poorly set up cage. In xnormal I could clearly see it, so I exported again all my ( 50 ) Hightpoly meshes, prayed for max to bear the polycounts  and did again my cage, tweaked it a lot, and it ended up working.  Sometime its seemed the cage was okay but some part were just too pushed resulting in wrong projection (just as Atticusmars pointed out ) I'm super happy, took me almost three days and much more bakes to finish that but thank to you I learnt a lot !


 As for the first exploded bake I dunno why it messed up because I payed attention to the cage and the HiPoly in max, but probably some human error from me while exporting. here are a few substance's screenshots of the meshes with normals.


Thanks so much again everyone !!


Niz

Scruples

Radical, have fun painting!

Nizidranamitz

Thanks !  I will !