Normals disappearing after re-importing

Luferac

Hi,

It's my first time handling normals and I am currently having quite of a struggle with it.

What happens is that after generating the normals, applying it to my model inside Maya and exporting the obj, when I import to confirm that all is well I realize the normal is not there anymore. 

Can you help me with what I am doing wrong / not doing?


Thanks in advance.

Regards.

Eric Chadwick

Do you mean normal map? What software are you importing into? Usually you need to set up a material in each software, and load the normal map into it.

Luferac

Hi Eric,

Yes, normal map. I am generating the normal map in xNormal and applying to the model in Maya by setting up a material and load the normal map exactly as you said. All looks fine, I then export the model as obj but I decided to import that same obj into Maya to verify that all is well but it's not.. after re-importing, the normal map is gone. Is that a Maya issue?

Eric Chadwick

That's an issue with the OBJ format. The Maya OBJ exporter should create a .MTL file, which is a text file describing the material. Sometimes MTL creation is an option in the export dialog, and not always enabled.

However the MTL material description is very limited, and may not contain a normal map. OBJ/MTL are very old formats, pre-dating widespread use of normal maps.

You can open the MTL file, it is a plain text format, so you can read it and see what it contains.

The OBJ importer has to be able to read and use the MTL file properly, converting it into a proper Maya material. I'm not sure if Maya's importer does this. Many importers do not do a good job of this.