Baked Normal map has a seam I don't know how to fix

Ootman

So the story is that I've been working on this character in Zbrush. I decided I would call it done, so I exported the High poly, set it up with the low poly in 3DS Max 2010, and I fixed all of the problems that showed up when rendering the normal map. I loaded it up in Crazybump to see how the low poly looked with the normal map, and I was happy with the result until I noticed some pretty obvious seams going directly along the UV seams.

I've tried expanding the padding and messing with some hard/soft edges, but I can't figure out how to get rid of the seam. I tried googling it, but there's a thousand different problems that create seams so I didn't find an answer there either.

I'm totally new to Polycount and forums in general, so I'm not sure of the best way to attach an image, I'm going to see if this works... It should be an image of the most obvious UV seam, as seen in Crazybump.

Any help would be greatly appreciated.

Joao Sapiro

why are you viewing it in crazybump and not on 3ds max ?

Ootman

I don't have the 3pointshader, so I'd have to do renders in max to see how the normal is working. Besides that, default lighting in max is pretty awful. In Crazy bump I can move the camera around the model and see it from any angle quickly and easily.

I did also try doing a couple renders in max though, hoping that maybe the seams were only in Crazybump, but that unfortunately wasn't the case.

ZacD

What is your target game engine or viewer? Crazybump isn't a good way to present models.

Ootman

I hadn't really thought about it that much, I just wanted it to look really good when I put it in my portfolio or try to animate it. If I was going to put it into a game engine though, I'd probably use CryEngine.

ZacD

There's so many different minor variations in normal maps, and some techniques are more important with certain apps, you should only test and try to fix issues on the target platform.

Ootman

Well I guess I'll try getting it into CryEngine to check it then, but I'm guessing that probably won't fix the seam?

ZacD

You could have completely different issues in CryEngine, it's hard to say how similar the 2 engines are.

Ootman

Well, it took some time to get everything set up, but I got the model into CryEngine. The seam on the foot I showed before is still there, but not as obvious, so here's a picture of the seam going around the shoulder.

Ootman

Well despite the disheartening lack of responses in the past week, I've continued attempting to solve this problem myself. I tried rendering the normal in XNormal, but the same seams occur. The only success I've had was when I tried using the 3pointshader.

While it didn't solve my problem or answer any questions, the seams have become nearly unnoticeable without getting absurdly close to the UV seams. The only place that's still apparent is around the shoulder, as it was in the picture I took in CryEngine.

So while I am quite pleased to see my model looking more like it should, it bothers me that the same normal map and same OBJ work with 3pointshader but get terrible seams anywhere else. Just thought I'd update in case anyone finds this thread and has any ideas?

ZacD

Try this http://docs.cryengine.com/display/SDKDOC3/Normal+map+baking+with+xNormal?desktop=true&macroName=english

Ootman

Well that CryTB.dll method sounds great and I was looking forward to trying it, but that page doesn't have a link or location for downloading it. I also checked in my CryEngine folder and couldn't find it anywhere. Even Google couldn't tell me where to find it. If anyone can share it somehow or tell me where it is, I'll definitely give it a shot.

I hadn't heard of Handplane before, but I just looked it up and I see how it might be able to help. I'll try to see if it'll help.

Oh, and thanks for the suggestions guys.

ZacD

I think it might of been renamed Crytiff but I could be wrong.

Ootman

Well I used Crytiffs for my export to CryEngine, but I just re-saved the baked normal map I got from 3DS Max. Turned it from a TGA to a Crytiff in Photoshop before making a final export file. Is that the same thing or did you mean there's a Crytiff plugin for XNormal as well?

ZacD

There's a Crytiff plugin for XNormal, not sure if it's the same thing as CryTB

divi

not 100% sure since you didnt post your UVs, but i might have come across this issue in the past. the solution i've found(there might be others out there) was to not rotate the uv shells after i cut the seam and if possible also straighten the seam on the U or V axis. preferably snap to a pixel edge as well, but that might be overkill ^^. but not rotating the uv shell should probably help with that problem.

Ootman

Well here's the Normal map, shrunk it down from 2048 to 512 and saved as a JPEG because I'm not sure how big Polycount lets us post images, but hopefully its good enough.

To be honest, I've thought about the pixels lining up properly, but I'm still pretty new to baking normal maps and doing UV layouts for characters in general, so I figured it would be extremely difficult if not impossible to get all the sides straight for an organic character like this. If I'm wrong or there's a trick to it, I'd love to hear it though.

iconoplast

Are you using a cage when you bake?

Ootman

So first of all, I tried Handplane and I'm thinking that object space normal maps must be different from the normal maps that I know how to use. I got some crazy normal map with yellows and greens and all sorts of colors, and doesn't seem to work all that well when I apply it to my model. Also it doesn't have the option of exporting for CryEngine, so that's unfortunate.

I also started looking into the Crytiff plugins for Xnormal, and it seems they exist, but I can't find those anywhere either. They don't seem to be in my CryEngine folders, and Google has once again failed to draw up any useful answers of where to find the files.

And to iconoplast, yeah, I built a cage in 3DS max with the projection modifier.

iconoplast

Just making sure!

Object space normal maps are indeed very different. Try putting the low poly and object space map in to handplane and use Max as the target -- it tends to work decently for CryEngine.