Painting over a computer rendering

One of my goals with this is to present what I'm doing in a way that family and friends can get. I want to show what i'm doing and the progress I'm making in a way everyone can see. So I know to people in the Art community some of my explanations will be obvious, Sorry about that.. lol.

About two years ago I started using a free 3d modeling program called sketchup. Its used for many purposes, but one is for concept art. Its good at blocking things in, then doing a paint over to finish the drawing off. I've done a few drawings like these, but I always end up giving up in the painting stage. This is another reason it has become clear to me I need to back up and work on my basics.

This is a computer render of a model I designed in sketchup. It started as a 2d drawing in photoshop, then was modeled, rendered, and I started to over paint. This is an example of where I was getting stuck. My next post will show some of the value sketches and stuff I've been doing recently to try and overcome these problems.

first sketch-

 Current work in progress, partially painted-

 Showing a after and before of painted area-

 And last but should be second, straight out of the renderer, before any photoshop-