Why do flat-surface 3D objects have shading artifacts???

[VeryAnnoyed2016]

Hello all - Just trying to put a 3D object in some art and have it shade properly.  Running into several issues.  Have years of experience with PS Elements, and am brand-spanking newbie to the full PS [Side Bar: is there a way to just buy the blessed full-featured 2019 or whatever latest PS (am not even sure of the name as there seems to be multiple versions CC this CC Pro that--I think the one I am using does not even have the CC) rather than the subscription approach?].  

1. The object is modeled with flat faces.  The .stl files have flat faces.  But when I add textures and save as an .obj, I get these weird shading artifacts that guessing there is a name for and it is a well-known thing.  Including a portion of the image below.  The shading artifacts are lots of v-shaped straight lines along the background surface that appears to be some sort of mathematical artifact from the mesh process.  (Seeking some education in this area.)  I tried making the .obj in Meshmixer and 3D Builder, same thing.  I tried importing the .stl into PS and then generating UV's, same thing.  The object is nice and flat until last step to make it useable...then garbage.  So, question #1 is understanding what is going on and how to get rid of this "puckering" shading artifact.  [Ego Disclaimer #: DontJudgeMe404. This is not how the final 3D object is intended to be textured, yada yada--this is earlier version I am backtrack experimenting with to resolve issues.]  

Thanks in advance for the info,

Richard

[Ussnorway]

you have a few questions there so I'll try to answer them but I may need to see your Dn file so these are best guess on my part;

q1 can you export models = yes... assuming you have the current build of Dimension Obj is always your best option and avoid exporting as Dn if you need to update computers or move between systems

q2 can you adjust materials = yes and no... there are two different types, normal i.e, Nvidia standard allows you to adjust everything but if you use a map {black and white mask image} then that overrides the sliders.

the second type is Substance materials and you need the Substance software to make | adjust these... they do have some adjustments but its up to who ever made them as to what those adjustments are

q3 sounds like you made a woppie like the first image below with lots of default materials you don't want?

the fix [see 2nd image] is to use the eyedrop sample tool

1 select one of the default materials you want to remove

2 use the eyedrop tool to click on a part of the model (in this example titanium is my base material)... the default material now is removed and replaced with what ever you clicked on

something like this?

q4 save to cc library is new and riddled with bugs so be careful

image 1 = how to get the model into your library... note that you should only select the model itself... the image you see in the library panel is a snapshot

what you get back out in Dimension is the model only however if you try to open the file in Photoshop its the snapshot that gets sent

q5 Photoshop can open but not import?

have you got all formats selected... is there more than one build of Photoshop installed on that system

q6 assuming you have the current build of Dimension and use the export to Obj option then models will import to Photoshop with whatever maps, materials etc they had in Dimension... lights don't import with Obj but you can add them after and Photoshop preview is very old school as has been pointed out before so save first, then do a rendor to see what the model will really look like once you get it in

as always, good luck and share your files = best chance to get good answers in stead of guesses

[VeryAnnoyed2016]

Thanks, had not seen how to export to .obj before...suppose presumed it would not work here since other attempts at .obj import to PS had the shading issue.  Surprises me to no end that cannot import a .dn file into PS?!?  That in theory would avoid the limitations of the .obj format.  

At any rate, I did get it to more or less properly import the .obj format...once.  The problem was that there were two other objects in the Dimension scene that also got exported.  Yes, I could delete them from inside PS but I decided to clean it up by deleting them in Dimension and exporting again.  Has not worked ever since!  (Yes, I restarted both Dimension & PS to attempt to fix, deleted all files in the dedicated folder for the export.)  Will experiment more on that soon and provide details/files with findings.  

Regarding the materials, I want to have different parts of the object(s) be different materials is all.  Not understanding how to use dropper for that, as Dimension treats entire scene as one object.  Have tried not "combine objects" during export in 123D but then the file will not load in 3D Builder or Dimension.  But the workaround--though tedious--is to make separate 123D files for each component and export them individually, then reassemble the object in Dimension (with different materials).  

Hopefully after all that, the compound object will export as .obj from Dimension and import correctly into PS.  

[VeryAnnoyed2016]

Ok!  The separate component exports assembled nicely in Dimension, exported to a .obj, and imported properly to PS.  No shadow "puckering" artifacts!  And can change their materials both in Dimension and PS.  Have a process that works.  

Thank you, all, for helping me work through this.