Maya Objs black

dinmeolas

Hi,
 Maya 2014
 Trying to create props to use in Vue so saving as Objs. Didnt have an issue til last night. When I save an Obj and open it in Vue or even maya the texture is gone and replaced by black  shading group. I hadnt changed any settings and after searching no fixes have worked. Does anyone have any ideas?
Thanks
Scott

JohnnyRaptor

possibly inverted normals. Try selecting the mesh, unlocking and flipping normals

dinmeolas

Hey, thx for the help. Normals are correct. Doing more testing and Blinn works fine so maybe its just Lamberts.  Will test others. Will run up mia-mat-x as really need my sp2 stuff. Will post what I find.
Thx again,
Scott

dinmeolas

very strange, No matter what I do once I save as Obj and reopen its black, lambert 2 turns into lambert2SG1 and has no shader, same with blinn, so something about eporting as Obj.  changes the shader designation? Am rather new so no clue on this.

throttlekitty

Do the objects have per-face materials assigned? There's a long-winded bug of sorts you can run into if so (multiple empty groups pointing to shading engines). Try breaking all material connections and reassigning one of your materials at the object level.

dinmeolas

throttlekitty said:

Do the objects have per-face materials assigned? There's a long-winded bug of sorts you can run into if so (multiple empty groups pointing to shading engines). Try breaking all material connections and reassigning one of your materials at the object level.

Thank you...what ive been testing with after the initial issue is just a simple cube...

throttlekitty

dinmeolas said:

Thank you...what ive been testing with after the initial issue is just a simple cube...

And you have the same issue?

quick edit: obj/mtl export references the name of the shading group not the material, that's why you get the lambert2SG instead of lambert2

dinmeolas

yes, doesnt appear to be specific to the mesh. Its exporting an Obj with a lambert. Upon import its black. I just  used a blinn and used a uvchecker jpg thru the blinn, exported as an obj and then imported and is fine. But if I use a lambert its just black, really weird.

throttlekitty

Something I forgot was that if you have a texture slotted in diffuse in Maya, it also sets the diffuse channel to black (which gets written to the mtl file). I don't know Vue, but some other programs I've used have two slots for diffuse: a texture slot and a diffuse tint slot. So it could just be that?

dinmeolas

in common material attributes im going to color and clicking on the file and adding a jpg to use.  My lambert2 shows the proper map and when I go into the  Hypershade editor and click that lambert2 and click for inputs and outputs the SG also shows the proper jpg image. But after I export that turns black and upon importing the cube it just shows the lambert2SG which is black and doesnt have the lambert2. Its like its not saving the jpg fueled lambert so the SG has nothing to use and is black. I just dont know whats going on, why its doing this and how to fix.  Can work around of course, just had thought  along w/ using meshes in Vue to post some props from practice as Objs on Renderosity as freebies. 
 Thx again for taking your time to help
Scott