Is my low poly the cause of my bad bakes?

RaptorCWS

I am working on a tar 21 and I think my low poly is the cause of bad bakes. doe groups of thin tris do that? here is cropped image of the normal of where one of the problems are happening.


This gun has a lot of molding and rounded parts some of which i have decided to just make as floating geometry on the low poly but some parts are cut right through. any suggestions on how to have this optimized and not going to cause problems baking?

Here is a link to the guns thread.

http://www.polycount.com/forum/showthread.php?t=147983

billymcguffin

Yes, long thin triangles cause shading issues. Are you using smoothing groups/hard edges on your lowpoly?

RaptorCWS

I did not set any up before i unwrapped it. is that a problem?

billymcguffin

Yeah, you should have a smoothing split on edges with sharp angles (maybe 50 degrees or so). This makes it so the normal map doesn't have to do as much work compensating for the normals of the lowpoly.

RaptorCWS

Thanks. Ok so I've read all of the threads on the importance of putting smoothing splits where you want hard edges and putting hard edges on their own UV island with edge padding, and adding edge loops around problem areas and I believe I understand that, but I am still having problems No matter what I do, smooth/ hard edge or attached or separate UV Island I still get some nasty artifacts in my bakes. and when I smooth some edges it causes problems all over the mesh's flat surfaces. cage/ no cage, about the same result.

What should I do about this? I have been trying to figure this out for 2 weeks and I feel like I am banging my head up against a wall.

Fwap

What software are you baking your maps out in?
Maybe upload a portion of your model and we can have a look?

RaptorCWS

Fwap wrote: »

What software are you baking your maps out in?
Maybe upload a portion of your model and we can have a look?

I'm baking in xnormal,

Here is a link to the receiver.

https://drive.google.com/folderview?id=0B2uEKvb_ntvQOUhxOW1SOXQzWlE&usp=sharing

Fwap

Hmm, i'm not seeing anything that stands out that might be causing the problem.
I'm inclined to say its party your cage though, I'm not sure what program you are modeling in but try tweaking the cage and UV splits at the troublesome spots.

Triangulate your entire mesh as well before baking it out, it should help with some of those bigger issues, i think you have some non planar faces in there.

As for the edges, i know you said you set your uv borders to have a hard normal, make sure that in your export options that the normals are being exported with your low poly.

SuperFranky

I would recommend you reading a Troubleshooting section in my Normal Mapping guide to see if you're doing anything wrong in preparing your mesh for baking.

huffer

Are you using Maya? Perhaps use Unlock normals and rebuild the hard edges?

[Deleted User]

There are couple problems with your normals.

From top to bottom:
- left side of your geometry after I oriented all normals in Houdini
- left side of you geometry directly after I downloaded it
- right side of your geometry after I oriented all normals in Houdini. Notice that there is a big problem with you polygon where arrow points.
- right side of your geometry directly after I downloaded it

In couple places you got theoritically flat geometry from two triangles, but normals on them doesn't point in the same direction, so they give you problems after baking. Plus this messed polygon on right side.

BTW. Take what I say with a big grain of salt, because I'm not a game modeler. I'm just saying what I see wrong with normals in your geometry after I loaded it into Houdini. Maybe guys knows some techniques that works in low poly that doesn't have to look exactly correct in viewport before normal texture applied. But the messed polygon for sure shouldn't be there

RaptorCWS

Thanks everyone, You all have helped solved those artifact problems... now I have ran into a skewing problem.

I tired adding geometry around the problem on the mesh I was using to bake but it seemed to have the opposite of my desired effect.

RaptorCWS

So I believe I understand Earthquakes and SuperFranky's post on normal maps after struggling with this stuff for over a month nowand how to avoid errors on them and their information has helped out a lot but i can not for the life of me get rid of these errors. There is no geoemety intersecting with my cage. Ive unlocked and re smoothed the normals in maya. Just nothing that I do seems to give me a clean bake. everywhere but these spots are fine.



These Uvs are temporary anyways, I just want to make sure I understand how to bake normal maps properly before unwrapping the whole gun.

pmiller001

The only time i get problems like that are when either of these things has/hasn't happened.
1. I didn't make a split near a 90 Degree angle(or another sharp angle)
2. There's a problem with my cage.
3. There's a problem with my low poly.