Hi parazaine
There's a free 3d package that includes modeling & rendering called Blender (
http://www.blender.org/), i haven't tried it myself but the new release is getting a lot of praise, it might be too complex for Oolite oxp-ing though, especially if you've no previous experience using 3d software - have you had a look at wings3d
www.wings3d.com for a free modeling package (used for building the actual ship geometry) and GIMP
www.gimp.org for a free texturing package (used for painting the metal surfaces (sometimes called 'textures' or 'skins' onto the ship once you've built it in wings)?
There's a great thread here
https://bb.oolite.space/viewtopic.php?t=5580 with a lot of tips on how to paint really great looking texture maps!
The griff thargoid gets a lot of it's shiny metal-ness from its 'shader'* files in it's oxp, the actual texture maps are quite drab and unexciting. The shader adds a fake reflection effect to the ships surface as well as ramping up the specular highlight intensity, these are what is really giving the ship its polished metal look.
You don't have to write a shader to access Oolites shader effects, most of them are available using the 'Materials' settings in your ships shipdata.plist file (
http://wiki.alioth.net/index.php/Materials_in_Oolite ), eg, for a shiny metal ship painting out a custom specular_map would be an option - make a greyscale copy of your colour texture map and then work over it using the brightness/contrast painting tools (dodge and burn). A specular map works like this, the parts of the image that are darker in tone will appear dull and less shiny in oolite than the parts of the specular map image that are lighter in tone.
*A shader is a small program written in glsl (
http://en.wikipedia.org/wiki/GLSL) that 'plugs into' oolites graphics engine and is used by oolite when it wants to know how to draw the relevent ship onto the screen,
if you want to experiment with shaders i highly recommend downloading a shader development program (i think maybe Apple Mac's come with a free one built in? If you're on a windows xp/vista pc you could try AMD's free 'Rendermonkey' program although annoyingly you have to register an email address with them before you can download it
http://developer.amd.com/gpu/rendermonk ... fault.aspx ).