Rocket Engine

[RocketNut]

Just something I'm working on.

[mirko]

it seems that your model is a half under the ground

[elliasp]

Yes, agree with mirko 

[PhilippeV8]

Other than the point made correctly by mirko, I'd suggest to increase Tessellation Quality.

[RocketNut]

Tessellation?

[elliasp]

Tesselation : the number of polygons if your polygons are triangles.

Renders are often better with quadrangles. But it's my opinion...

[RocketNut]

How do I increase the number of polygons? I am using KeyShot that came with my CAD package (Alibre).

[PhilippeV8]

Depending on what package you use ...

There have been 2 situations so far I think.  Either you can set tessellation detail on the import dialog in KS.  If not, you need to find such a setting in your CAD program.

The tessellation can be seen in your render on the edges of the round parts.  There where you got corners instead of a smooth circle ..