Preparing 3dMax Models for Substance Painter

[Anonymous]

Hello, I have one problem

I haven't used Max for some time. I want to prepare my old models done in 3d's Max for Substance Painter. I used the following tutorials so problem is that they were not prepared in the tutorial with the procedure how they were made. I would like to work on them in Substance Panter to include in my Portfolio. Problem is that I followed two tutorials on how to do that and none of them worked. Not sure is a problem with Unwrapping or assigning Ids. because models have a lot of parts. With my Tank model, I assigned different Id's then changed color and connected them as diffuse maps in Slate Material Editor. Then after Collapsing to Editable Poly and Unwrapping I started to Render To Texture. Problem is that it is not allowing me to render only Unwrap. I cannot export diffuse maps which are necessary to work in Substance Painter. Later in Substance Painter, it cannot bake fully because of problems with ids. Can someone explain to me the procedure so I can model them the right way to prepare them for Substance Painter. I used only Saline Renderer on those models when I started to learn Max. 

I followed these two tutorials and didn't work out

https://www.youtube.com/watch?v=o_N2rkMhk7Q&t=159s&ab_channel=MatthewPorcaro

https://www.youtube.com/watch?v=l8BZWU2NGVQ&t=1111s&ab_channel=PhotoBots