Batch Bake Error Maya

ENODMI

Getting a strange error when I try to batch bake lighting from my normals in Maya. Everything seems to be in order, normals facing same direction, uvs not flipped/overlapping, renderview preview from MR looks fine... but once I bake it to texture one side gets flipped lighting on one side. There arent any negative attributes that im aware of and the geo isnt parented to anything else. Ive frozen all attributes and cleared all of its history. Ive also tried exporting it out as an obj and importing it clean, but still no luck. I just cant figure out whats going on!?!? Anyone ever encountered something similar?

warby

- can you turn off double sided polys and than post highres close ups of the seam!? it looks soft to me in this pic as if the error was within the texture and not just mayas display also what does the actual lightmap look like why didnt you post it ? and if you bake occlusion what does that look like post please !? need more data !

ENODMI

Theres obviously some sort of negative attribute on the left side since the lighting is being reversed in the bake... i just dont know why or where to look for it. Its strange that It renders fine in the renderview, but not when it bakes to the texture.


Oh, and double sided polys is off

toddiej

I don't think I've ran into that particular problem but similar things. I'd try combining the object with a new sphere then delete the sphere and delete history and freeze transformations.

warby

okay so the issue is definitly that mental ray interprets the data it gets differently than the maya realtime viewport stuff ...and the seam ultimatly is in fact in the texture ...

if you want to research this further id assign your normal map material to a cube or better yet a plane bake that and see if it comes out messed up if not than we know there is something wrong with your low poly model

if you have a tight deadline on your shoulders id say just invert the green chanel of your normal map in photoshop bake it a second time and than stitch those 2 renders left and right together in photoshop

ZacD

turn on view normals in the view port and screen shot it.

ENODMI

Normals seem to be fine. Im going to try and rebuild the lowpoly and see if anything changes. somewhere in my process im getting negetive values locked in my lowpoly. Im thinking MR doesnt like the way im mirroring my geo

warby

have you tried "unlock normals" yet and than resmooth all the edges ?

my money is also on some form of corruption in the model that happens when you mirrored it. although nothing like that ever happend to me ... how did you mirror it btw ?

ENODMI

Well I give up. I have no idea what happened to this geo. I remade a similar scene to to test my workflow and I cant duplicate this error! Everything bakes out just fine...so...who knows!? Thanks guys for all your help.

warby

can you send me the model and the normal map i am curious !

ENODMI

Heres a link to the obj, maya scene and normal map. Thanks for taking a look. Hopefully its nothing too embarrassingly obvious:)

http://dl.dropbox.com/u/29382022/face%20lp.rar

mikezoo

dude, i have had this issue before when baking out lightmaps. I have no idea how or why it happens. Ive created new scenes and exported geometry out and yet still have the issue. Other times the issue fixes itself. If i learn anymore I'' be sure to share.

warby

okay here are my findings:

-there is nothing wrong with you model if i map the normal map onto a simple LOD verison of your face that i made out of a cube it fucks up as well without having mirrored anything.

-the orientation of the model has an effect on where the artifact appears if you rotate the model towards -X you wont get a seam in the face but probably on her back ( wasnt included in your model)

-its a mental ray bug

mikezoo

sooooo I managed to "fix" my problems with the batch bake artifacting.

In this particular case I combined my mesh with a Uv'ed primative cube. Exported them out and just imported them back into maya.

magic! it worked. Which is strange because I feel like I already tried this method. But the solution seems to make sense with new vert IDs

Give it a go.

ENODMI

Returning with a small update for anyone encountering similar. When building this model I was using Maya 2012. Ive since gone back to Maya 2010 and I have had no issues. So like Warby said, "Its a Mental Ray bug", at least in 2012

disanski

Just an idea from a max user I had similar problem in max and I could not figure out what did I break again turned out in max 2012 they have gamma correction on by default so I just had to disable it and it was fine. Do you guys have something similar in Maya?