It'll generally be obvious to the trained eye that it's in engine. These days there's no real excuse not to put it in an engine or real time viewer, with free access to the latest tech (UE4, Unity) or the ability time view real time assets at high real-time quality in Substance or Marmoset, etc. Putting things in engine is…
For the finish product, you should show them in game engine. Download Unreal Engine 4 and do whatever it takes to look good in it. For high poly sculpt, show them as is. Render them out with grey shader.
Doesn't really matter how you render your hp, it just has to look good. Lp should be always rendered in a game engine. Depending on the asset, you can add displacement, but actually its still not used widely...
thanks a lot PANUPAT AND OBSURA! any reason to use unreal over unity? or is it basically the same and just personal preference also how do I show that its in engine? Just maybe a little txt in the image or video? you guys got any links to good starting portfolios that are doing this? THANKS AGAIN! you guys are awesome