Hi there! Sorry for the late response, had a long day.
The realtime render engine is the directX 9 engine, the one and the same. The shaders also are the same.
So when you render to file, WYSIWYG will be rendered to file.
So I guess you can say the game engine is default on the WS of trueSpace.
Now you can play with the lights and shaders and normal maps and stuff, etc, even do some animations. Do bear in mind that the more lights you have and the more geometry you have, the lower framerates you'll get. Also, subdivision will affect things a lot, also 4K images or higher.
But if works well for a nice game engine with 3D modeling and animation, though it would be great to have another stabler DirectX 11 engine one of these days with trueSpace features. I have a contact somewhere who made a W8 touch friendly direct X 11 modeller software, but it's not released yet......
I have attached a D3D shader based off Augustos multipurpose shader. It has images, dual normal map and reflective and specular properties and transparency properties that will do things as you need for practically any shader, if you need some other lambert or blinn or a fusion of blinn+phong others, I think I can get them to you also.
I also have some good foilage and translucent shaders out there.
Also, if you have a good graphics card, you should totally check out mt AO or IBL light rigs out there in the forums.
Here and
Here